CN110692152A - Alkali metal battery with deformable quasi-solid electrode material - Google Patents

Abstract

An alkali metal cell and a method of making the alkali metal cell with a quasi-solid electrode are provided, the method comprising: (a) combining an amount of active material, an amount of electrolyte, and a conductive additive to form a deformable and conductive electrode material, wherein the conductive additive containing conductive filaments forms a 3D network of electron conducting pathways; (b)forming the electrode material as a quasi-solid electrode, wherein the forming step comprises deforming the electrode material into an electrode shape without interrupting the 3D network of electron conduction pathways, thereby causing the electrode to remain no less than 10^‑6Conductivity of S/cm; (c) forming a second electrode; and (d) forming an alkali metal cell by combining the quasi-solid electrode and the second electrode, the alkali metal cell having an ion-conducting membrane disposed between the two electrodes.

Description

Alkali metal battery with deformable quasi-solid electrode material

Cross Reference to Related Applications

This application claims priority from U.S. patent application No. 15/604,606 filed on 24.5.2017 and U.S. patent application No. 15/604,607 filed on 24.5.2017, which are incorporated herein by reference.

Technical Field

The present invention relates generally to the field of alkali metal batteries, including rechargeable lithium metal batteries, sodium metal batteries, lithium ion batteries, sodium ion batteries, lithium ion capacitors, and sodium ion capacitors.

Background

Historically, the most popular rechargeable energy storage devices today-lithium ion batteries-were actually developed from rechargeable "lithium metal batteries" that use lithium (Li) metal or Li alloys as the anode and Li intercalation compounds as the cathode. Li metal is an ideal anode material due to its light weight (the lightest metal), high electronegativity (-3.04V versus standard hydrogen electrode), and high theoretical capacity (3,860 mAh/g). Based on these outstanding characteristics, lithium metal batteries were proposed 40 years ago as an ideal system for high energy density applications. In the mid 1980 s, several prototypes of rechargeable Li metal batteries were developed. A notable example is a battery constructed of a Li metal anode and a molybdenum sulfide cathode developed by MOLI Energy, Inc. This and several other batteries from different manufacturers were abandoned due to a series of safety issues arising from the sharp inhomogeneity of Li growth (formation of Li dendrites) when the metal was re-plated during each subsequent recharge cycle. As the number of cycles increases, these dendritic or dendritic Li structures may eventually pass through the separator to the cathode, causing an internal short circuit.

To overcome these safety problems, several alternative methods have been proposed in which the electrolyte or anode is modified. One approach involves replacing the Li metal with graphite (another Li insertion material) as the anode. The operation of such batteries involves shuttling Li ions between two Li insertion compounds and are therefore referred to as "Li-ion batteries". It is speculated that Li-ion batteries are inherently safer than Li-metal batteries because Li exists in its ionic rather than metallic state.

Lithium ion batteries are the primary candidate energy storage devices for Electric Vehicles (EV), renewable energy storage, and smart grid applications. The last two decades have witnessed a constant improvement in energy density, rate capability and safety of Li-ion batteries, but for some reason Li metal batteries of significantly higher energy density have been largely ignored. However, the use of graphite-based anodes in Li-ion batteries has several distinct disadvantages: low specific capacity (372 mAh/g theoretical capacity versus 3,860mAh/g for Li metal), long Li intercalation times (e.g., low solid state diffusion coefficient of Li into and out of graphite and inorganic oxide particles) require long recharge times (e.g., 7 hours for electric vehicle batteries), do not impart high pulse power (power density < <1kW/kg), and require the use of pre-lithiated cathodes (e.g., lithium cobalt oxide), thereby limiting the choice of usable cathode materials. Moreover, these commonly used cathodes have relatively low specific capacities (typically <200 mAh/g). These factors have contributed to two major drawbacks of today's Li-ion batteries-low gravimetric and volumetric energy densities (typically 150-.

The emerging EV and renewable energy industries require the availability of rechargeable batteries with significantly higher gravimetric energy densities (e.g. requirements > >250Wh/kg and preferably > >300Wh/kg) and higher power densities (shorter recharge times) than current Li-ion battery technologies can provide. Furthermore, the microelectronics industry requires batteries with significantly greater volumetric energy densities (>650Wh/L, preferably >750Wh/L) because consumers need to have smaller volume and more compact portable devices (e.g., smartphones and tablets) that store more energy. These requirements have led to considerable research efforts to develop electrode materials for lithium ion batteries with higher specific capacity, excellent rate capability and good cycling stability.

Several elements from groups III, IV and V of the periodic table can alloy with Li at certain desired voltages. Therefore, various anode materials based on such elements and some metal oxides have been proposed for use in lithium ion batteries. Among these, silicon has been considered as one of the next-generation anode materials for high-energy lithium ion batteries because it has nearly 10 times higher theoretical gravimetric capacity (based on Li) than graphite_3.753,590mAh/g of Si vs. LiC₆372mAh/g) and about 3 times greater volumetric capacity. However, during lithium ion alloying and dealloying (cell charging and discharging), significant volume changes of Si (up to 380%) often result in severe and rapid battery performance degradation. The performance decay is mainly due to the pulverization caused by the volume change of Si and the inability of the binder/conductive additive to maintain electrical contact between the pulverized Si particles and the current collector. In addition, the inherently low conductivity of silicon is another challenge to be addressed.

Although several high capacity anode active materials (e.g., Si) have been discovered, there are no corresponding high capacity cathode materials available. The cathode active materials commonly used in current Li-ion batteries have the following serious drawbacks:

(1) the practical capacities that can be achieved with current cathode materials (e.g., lithium iron phosphate and lithium transition metal oxides) have been limited to the range of 150-250mAh/g, and in most cases, less than 200 mAh/g.

(2) The insertion and extraction of lithium into and out of these conventional cathodes is dependent uponLi has a very low diffusion coefficient (typically 10)^-8To 10^-14cm²S) in the solid particles (leading to very low power density (another long standing problem with present day lithium ion batteries)).

(3) Current cathode materials are electrically and thermally insulating and do not efficiently and effectively transport electrons and heat. Low conductivity means high internal resistance and the need to add large amounts of conductive additives, effectively reducing the proportion of electrochemically active material in the cathode which already has low capacity. Low thermal conductivity also means a higher tendency to suffer thermal runaway, which is a major safety issue in the lithium battery industry.

Low capacity anode or cathode active materials are not the only problems facing the lithium ion battery industry. There are serious design and manufacturing problems that the lithium ion battery industry does not seem to recognize or to largely ignore. For example, despite high gravimetric capacity at the electrode level (based on the weight of the anode or cathode active material alone) as often required in publications and patent documents, these electrodes unfortunately cannot provide batteries with high capacity (based on total battery cell weight or battery pack weight) at the battery cell or battery pack level. This is due to the following view: in these reports, the actual active material mass loading of the electrode was too low. In most cases, the mass loading (areal density) of active material of the anode is significantly below 15mg/cm²And most are<8mg/cm²(areal density-the amount of active material per electrode cross-sectional area along the thickness of the electrode). The amount of cathode active material is typically 1.5-2.5 times higher than the anode active material. As a result, the weight proportion of anode active material (e.g., graphite or carbon) in a lithium ion battery is typically from 12% to 17%, and cathode active material (e.g., LiMn)₂O₄) In a weight proportion of from 17 to 35% (mostly<30%). The weight fraction of the combined cathode active material and anode active material is typically from 30% to 45% of the cell weight.

As a completely different class of energy storage devices, sodium batteries have been considered as an attractive alternative to lithium batteries because of the abundant sodium content and the significantly more environmentally friendly production of sodium compared to the production of lithium. In addition, the high cost of lithium is a major problem.

Several research groups have described sodium-ion batteries using hard carbon-based anodes (Na-carbon intercalation compounds) and sodium transition metal phosphates as cathodes. However, these sodium-based devices exhibit even lower specific energy and rate performance than Li-ion batteries. These conventional sodium ion batteries require the diffusion of sodium ions into and out of the sodium intercalation compound at both the anode and cathode. The required solid state diffusion process of sodium ions in sodium ion batteries is even slower than the Li diffusion process in Li ion batteries, resulting in an excessively low power density.

Instead of hard carbon or other carbonaceous intercalation compounds, sodium metal may be used as the anode active material in the sodium metal cells. However, the use of metallic sodium as the anode active material is generally considered undesirable and dangerous due to dendrite formation, interfacial aging and electrolyte incompatibility issues. Most notably, the same flammable solvents previously used for lithium secondary batteries are also used in most sodium metal or sodium ion batteries.

The low active material mass loading was mainly due to the inability to obtain thicker electrodes (thicker than 100-200 μm) using conventional slurry coating procedures. This is not a trivial task as one might think, and for the purpose of optimizing cell performance, electrode thickness is not a design parameter that can be varied arbitrarily and freely. Conversely, thicker samples tend to become extremely brittle or have poor structural integrity, and will also require the use of large amounts of binder resin. Low areal and bulk densities (associated with thin electrodes and poor packing densities) result in relatively low volumetric capacity and low volumetric energy density of the battery cell.

With the increasing demand for more compact and portable energy storage systems, there is a strong interest in increasing the utilization of the volume of the battery. Novel electrode materials and designs that enable high volumetric capacity and high mass loading are critical to achieving improved cell volumetric capacity and energy density.

Thus, there is a clear and urgent need for lithium and sodium batteries with high active material mass loading (high areal density), high electrode thickness without significantly reducing electron and ion transport rates (e.g., with improved conductivity), high capacity, high power density, and high energy density. These batteries must be produced in an environmentally friendly manner.

Disclosure of Invention

The present invention provides a method of producing a lithium or sodium battery having a high active material mass loading, exceptionally low overhead weight and volume (relative to active material mass and volume), high capacity, and unprecedented high energy and power densities. The lithium or sodium battery may be a primary (non-rechargeable) or secondary (rechargeable) battery, including rechargeable lithium or sodium metal batteries (having a lithium or sodium metal anode) and lithium ion or sodium ion batteries (e.g., having a first lithium intercalation compound as the anode active material and a second lithium intercalation or absorbing compound having a much higher electrochemical potential than the first lithium intercalation compound as the cathode active material). The alkali metal battery also includes a lithium ion capacitor and a sodium ion capacitor, wherein the anode is a lithium ion or sodium ion cell type anode and the cathode is a supercapacitor cathode (e.g., activated carbon or graphene sheets as an active material used in an electric double layer capacitor or a redox quasi-capacitor).

In certain embodiments, the present disclosure provides an alkali metal cell comprising: (a) a quasi-solid cathode comprising from about 30% to about 95% by volume of a cathode active material, from about 5% to about 40% by volume of a first electrolyte comprising an alkali metal salt dissolved in a solvent, and from about 0.01% to about 30% by volume of a conductive additive, wherein the conductive additive comprising conductive filaments forms a 3D network of electron conducting pathways, whereby the quasi-solid electrode has from about 10^-6A conductivity of S/cm to about 300S/cm; (b) an anode; and (c) an ion-conducting membrane or porous separator disposed between the anode and the quasi-solid cathode; whereinThe quasi-solid cathode has a thickness of not less than 200 μm. The quasi-solid cathode preferably contains not less than 10mg/cm²Preferably not less than 15mg/cm²Further preferably not less than 25mg/cm²More preferably not less than 35mg/cm²Still more preferably not less than 45mg/cm²And most preferably greater than 65mg/cm²Mass loading of cathode active material.

In the cell, the anode may comprise a quasi-solid anode comprising about 30% to about 95% by volume of an anode active material, about 5% to about 40% by volume of a second electrolyte comprising an alkali metal salt dissolved in a solvent, and about 0.01% to about 30% by volume of a conductive additive, wherein the conductive additive comprising conductive filaments forms a 3D network of electron conducting pathways, such that the quasi-solid anode has from about 10^-6A conductivity of S/cm to about 300S/cm; wherein the quasi-solid anode has a thickness of not less than 200 μm. The quasi-solid anode preferably contains not less than 10mg/cm²Preferably not less than 15mg/cm²Further preferably not less than 25mg/cm²More preferably not less than 35mg/cm²Still more preferably not less than 45mg/cm²And most preferably greater than 65mg/cm²Mass loading of anode active material.

In certain embodiments, the present disclosure provides an alkali metal cell comprising: (A) a quasi-solid anode comprising from about 30% to about 95% by volume of an anode active material, from about 5% to about 40% by volume of an electrolyte comprising an alkali metal salt dissolved in a solvent, and from about 0.01% to about 30% by volume of a conductive additive, wherein the conductive additive comprising conductive filaments forms a 3D network of electron conducting pathways, whereby the quasi-solid electrode has from about 10^-6A conductivity of S/cm to about 300S/cm; (B) a cathode; and (C) an ion-conducting membrane or porous separator disposed between the anode and the quasi-solid cathode; wherein the quasi-solid cathode has a thickness of not less than 200 μm.

The invention also provides a method for preparing the quasi-solid capacitorA method of an alkali metal cell of a pole, the method comprising: (a) combining an amount of active material (anode active material or cathode active material), an amount of electrolyte, and a conductive additive to form a deformable and conductive electrode material, wherein the conductive additive containing conductive filaments forms a 3D network of electron conducting pathways; (b) forming the electrode material as a quasi-solid electrode, wherein the forming step comprises deforming the electrode material into an electrode shape without interrupting the 3D network of electron conduction pathways, thereby causing the electrode to remain no less than 10^-6S/cm (preferably not less than 10)^-5S/cm, more preferably not less than 10^-3S/cm, further preferably not less than 10^-2S/cm, still more preferably and typically not less than 10^-1S/cm, even more typically and preferably not less than 1S/cm, and further more typically and preferably not less than 10S/cm and up to 300S/cm); (c) forming a second electrode (the second electrode may also be a quasi-solid electrode); and (d) forming an alkali metal cell by combining the quasi-solid electrode and the second electrode, the alkali metal cell having an ion-conducting membrane disposed between the two electrodes.

The electrolyte may be a quasi-solid electrolyte containing a lithium salt or a sodium salt dissolved in a liquid solvent, the salt concentration being from 2.5M to 14M; preferably greater than 3M, more preferably greater than 3.5M, further preferably greater than 5M, still more preferably greater than 7M, and even more preferably greater than 10M. In the case where the salt concentration is not less than 2.5M, the electrolyte is no longer a liquid electrolyte; rather, it is a quasi-solid electrolyte. In certain embodiments, the electrolyte is a quasi-solid electrolyte containing a lithium or sodium salt dissolved in a liquid solvent, with a salt concentration from 3.0M to 11M.

In certain embodiments, the conductive filament is selected from a carbon fiber, a graphite fiber, a carbon nanofiber, a graphite nanofiber, a carbon nanotube, an acicular coke, a carbon whisker, a conductive polymer fiber, a conductive material coated fiber, a metal nanowire, a metal fiber, a metal wire, a graphene sheet, an expanded graphite platelet, combinations thereof, or combinations thereof with non-filament conductive particles.

In certain embodiments, the electrode is maintained from 10^-5A conductivity of S/cm to about 1S/cm.

In certain embodiments, the deformable electrode material has a thickness of 1,000s^-1An apparent viscosity of not less than about 10,000Pa-s, measured at an apparent shear rate. In certain embodiments, the deformable electrode material has a thickness of 1,000s^-1Is not less than about 100,000Pa-s at an apparent shear rate.

In the method, the amount of active material typically comprises from about 20% to about 95% by volume of the electrode material, more typically from about 35% to about 85% by volume of the electrode material, and most typically from about 50% to about 75% by volume of the electrode material.

Preferably, the step of combining the active material, the conductive additive, and the electrolyte (including dissolving the lithium or sodium salt in the liquid solvent) follows a specific sequence. This step comprises first dispersing the conductive filaments in a liquid solvent to form a homogeneous suspension, then adding the active material in the suspension and dissolving a lithium or sodium salt in the liquid solvent of the suspension. In other words, the conductive filaments must first be uniformly dispersed in the liquid solvent before other ingredients, such as active materials, are added, and before lithium or sodium salts are dissolved in the solvent. This sequence is crucial for achieving percolation of the conductive filaments in order to form a 3D network of electron conducting pathways. Without following this sequence, percolation of the conductive filaments may not occur or only occur upon addition of an excessively large proportion of conductive filaments (e.g., > 10% by volume), which would reduce the fraction of active material and thus the energy density of the cell.

In certain embodiments, the step of combining and forming the electrode material into a quasi-solid electrode comprises dissolving a lithium salt or a sodium salt in a liquid solvent to form an electrolyte having a first salt concentration and subsequently removing a portion of the liquid solvent to increase the salt concentration, thereby obtaining a quasi-solid electrolyte having a second salt concentration that is higher than the first concentration and preferably higher than 2.5M (and more preferably from 3.0M to 14M).

The step of removing a portion of the solvent may be performed in a manner that does not cause precipitation or crystallization of the salt and the electrolyte is in a supersaturated state. In certain preferred embodiments, the liquid solvent comprises a mixture of at least a first liquid solvent and a second liquid solvent and the first liquid solvent is more volatile than the second liquid solvent, wherein the step of removing a portion of the liquid solvent comprises partially or completely removing the first liquid solvent.

There is no limitation on the type of anode active material or cathode active material that can be used to practice the present invention. Preferably, however, the anode active material exceeds Li/Li when the battery is charged⁺(i.e. with respect to Li → Li as the standard potential)⁺+e^-) Lithium ions are absorbed at an electrochemical potential of less than 1.0 volt, preferably less than 0.7 volt.

In certain preferred embodiments, the alkali metal cell is a lithium metal battery, a lithium ion battery, or a lithium ion capacitor, wherein the anode active material is selected from the group consisting of: (a) particles of lithium metal or lithium metal alloy; (b) natural graphite particles, artificial graphite particles, mesocarbon microbeads (MCMB), carbon particles (including soft and hard carbon), needle coke, carbon nanotubes, carbon nanofibers, carbon fibers, and graphite fibers; (c) silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), nickel (Ni), cobalt (Co), manganese (Mn), titanium (Ti), iron (Fe), and cadmium (Cd); (d) alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al or Cd with other elements, wherein the alloys or compounds are stoichiometric or non-stoichiometric; (e) oxides, carbides, nitrides, sulfides, phosphides, selenides, and tellurides of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, Ni, Co, Ti, Mn, or Cd, and mixtures or composites thereof; (f) a prelithiated version thereof; (g) pre-lithiated graphene sheets; and combinations thereof.

In certain embodiments, the alkali goldThe generic cell is a sodium metal cell or a sodium ion cell and the active material is an anode active material comprising a sodium intercalation compound selected from: petroleum coke, carbon black, amorphous carbon, activated carbon, hard carbon (hard-to-graphitize carbon), soft carbon (easily-graphitize carbon), template carbon, hollow carbon nanowire, hollow carbon sphere, titanate, NaTi₂(PO₄)₃、Na₂Ti₃O₇、Na₂C₈H₄O₄、Na₂TP、Na_xTiO₂(x ═ 0.2 to 1.0), Na₂C₈H₄O₄Materials based on carboxylic acid salts, C₈H₄Na₂O₄、C₈H₆O₄、C₈H₅NaO₄、C₈Na₂F₄O₄、C₁₀H₂Na₄O₈、C₁₄H₄O₆、C₁₄H₄Na₄O₈Or a combination thereof.

In certain embodiments, the alkali metal cell is a sodium metal cell or a sodium ion cell and the active material is an anode active material selected from the group consisting of: (a) particles of sodium metal or sodium metal alloy; (b) natural graphite particles, artificial graphite particles, mesocarbon microbeads (MCMB), carbon particles, needle coke, carbon nanotubes, carbon nanofibers, carbon fibers, and graphite fibers; (c) sodium-doped silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), titanium (Ti), cobalt (Co), nickel (Ni), manganese (Mn), cadmium (Cd), and mixtures thereof; (d) sodium-containing alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Co, Ni, Mn, Cd, and mixtures thereof; (e) sodium-containing oxides, carbides, nitrides, sulfides, phosphides, selenides, tellurides, or antimonides of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, Ti, Co, Ni, Mn, Cd, and mixtures or composites thereof; (f) a sodium salt; and (g) graphene sheets pre-loaded with sodium ions; and combinations thereof.

In certain embodiments, the alkali metal cell is a sodium metal cell or a sodium ion cell and the active material is a cathode active material comprising a sodium intercalation compound or a sodium absorbing compound selected from: inorganic materials, organic or polymeric materials, metal oxide/phosphate/sulfide, or combinations thereof. The metal oxide/phosphate/sulfide may be selected from sodium cobalt oxide, sodium nickel oxide, sodium manganese oxide, sodium vanadium oxide, sodium mixed metal oxide, sodium/potassium transition metal oxide, sodium iron phosphate, sodium/potassium iron phosphate, sodium manganese phosphate, sodium/potassium manganese phosphate, sodium vanadium phosphate, sodium/potassium vanadium phosphate, sodium mixed metal phosphate, transition metal sulfide, or combinations thereof.

The inorganic material may be selected from sulfur, sulfur compounds, lithium polysulfides, transition metal dichalcogenides, transition metal trichalcogenides, or combinations thereof. In certain embodiments, the inorganic material is selected from TiS₂、TaS₂、MoS₂、NbSe₃、MnO₂、CoO₂Iron oxide, vanadium oxide, or a combination thereof.

In some embodiments, the alkali metal cell is a sodium metal cell or a sodium ion cell and the active material is a cathode active material comprising a sodium intercalation compound selected from: NaFePO₄、Na_(1-x)K_xPO₄、Na_0.7FePO₄、Na_1.5VOPO₄F_0.5、Na₃V₂(PO₄)₃、Na₃V₂(PO₄)₂F₃、Na₂FePO₄F、NaFeF₃、NaVPO₄F、Na₃V₂(PO₄)₂F₃、Na_1.5VOPO₄F_0.5、Na₃V₂(PO₄)₃、NaV₆O₁₅、Na_xVO₂、Na_0.33V₂O₅、Na_xCoO₂、Na_2/3[Ni_1/3Mn_2/3]O₂、Na_x(Fe_{1/ 2}Mn_1/2)O₂、Na_xMnO₂、λ-MnO₂、Na_xK_(1-x)MnO₂、Na_0.44MnO₂、Na_0.44MnO₂/C、Na₄Mn₉O₁₈、NaFe₂Mn(PO₄)₃、Na₂Ti₃O₇、Ni_1/3Mn_1/3Co_1/3O₂、Cu_0.56Ni_0.44HCF、NiHCF、Na_xMnO₂、NaCrO₂、Na₃Ti₂(PO₄)₃、NiCo₂O₄、Ni₃S₂/FeS₂、Sb₂O₄、Na₄Fe(CN)₆/C、NaV_1-xCr_xPO₄F、Se_zS_y(y/z ═ 0.01 to 100), Se, phosphomanalite (alluaudites), or combinations thereof, wherein x is from 0.1 to 1.0.

In some preferred embodiments, the cathode active material contains a lithium intercalation compound selected from the group consisting of: lithium cobalt oxide, doped lithium cobalt oxide, lithium nickel oxide, doped lithium nickel oxide, lithium manganese oxide, doped lithium manganese oxide, lithium vanadium oxide, doped lithium vanadium oxide, lithium mixed metal oxide, lithium iron phosphate, lithium vanadium phosphate, lithium manganese phosphate, lithium mixed metal phosphate, metal sulfides, and combinations thereof.

The electrolyte may be an aqueous liquid, an organic liquid, an ionic liquid (ionic salt having a melting temperature below 100 ℃, preferably below 25 ℃ at room temperature), or a mixture of an ionic liquid and an organic liquid in a ratio of from 1/100 to 100/1. Organic liquids are desirable, but ionic liquids are preferred.

In a preferred embodiment, the quasi-solid electrode has a thickness of from 200 μm to 1cm, preferably from 300 μm to 0.5cm (5mm), further preferably from 400 μm to 3mm, and most preferably from 500 μm to 2.5mm (2,500 μm). If the active material is an anode active material, the anode active material has not less than 25mg/cm²(preferably not less than 30 mg/cm)²And more preferably not less than 35mg/cm²) And/or at least of the entire battery cell by weight or volume25% (preferably at least 30% and more preferably at least 35%). If the active material is a cathode active material, the cathode active material preferably has not less than 20mg/cm for organic or polymeric materials in the cathode²(preferably not less than 25 mg/cm)²And more preferably not less than 30mg/cm²) Or not less than 45mg/cm for inorganic and non-polymeric materials²(preferably not less than 50 mg/cm)²And more preferably not less than 55mg/cm²) And/or a mass loading of at least 45% (preferably at least 50% and more preferably at least 55%) by weight or by volume of the entire battery cell.

The above requirements for electrode thickness, anode active material areal mass loading or mass fraction relative to the entire battery cell, or cathode active material areal mass loading or mass fraction relative to the entire battery cell are not possible in the case of conventional lithium or sodium batteries using conventional slurry coating and drying processes.

In some embodiments, the anode active material is a prelithiated version of a graphene sheet selected from pristine graphene, graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, boron-doped graphene, nitrogen-doped graphene, chemically functionalized graphene, a physically or chemically activated or etched version thereof, or a combination thereof. Surprisingly, the resulting lithium battery cells do not exhibit satisfactory cycle life (i.e., rapid capacity fade) without prelithiation.

In some embodiments of the inventive method, the cell is a lithium metal cell or a lithium ion cell containing a cathode active material selected from a lithium intercalation compound or a lithium absorbing compound selected from an inorganic material, an organic or polymeric material, a metal oxide/phosphate/sulfide, or a combination thereof. For example, the metal oxide/phosphate/sulfide may be selected from lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium vanadium oxide, lithium mixed metal oxide, lithium iron phosphate, lithium manganese phosphate, lithium vanadium phosphate, lithium mixed metal phosphate, lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide,a transition metal sulfide, or a combination thereof. The inorganic material is selected from sulfur, sulfur compounds, lithium polysulfides, transition metal dichalcogenides, transition metal trichalcogenides, or combinations thereof. In particular, the inorganic material is selected from TiS₂、TaS₂、MoS₂、NbSe₃、MnO₂、CoO₂Iron oxide, vanadium oxide, or a combination thereof. These will be discussed further later.

In the lithium metal battery, the cathode active material contains a lithium intercalation compound selected from a metal carbide, a metal nitride, a metal boride, a metal dichalcogenide, or a combination thereof. In some embodiments, the cathode active material contains a lithium intercalation compound selected from: an oxide, dichalcogenide, trichalcogenide, sulfide, selenide, or telluride of niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, vanadium, chromium, cobalt, manganese, iron, or nickel in the form of a nanowire, nanodisk, nanoribbon, or nanoplatelet. Preferably, the cathode active material contains a lithium intercalation compound selected from nanodiscs, nanoplatelets, nanocoatings or nanoplatelets of an inorganic material selected from: (a) bismuth selenide or bismuth telluride, (b) a di-or tri-chalcogenide of a transition metal, (c) a sulfide, selenide, or telluride of niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, cobalt, manganese, iron, nickel, or a transition metal; (d) boron nitride, or (e) a combination thereof; wherein the disc, platelet or sheet has a thickness of less than 100 nm.

In some embodiments, the cathode active material in the lithium metal battery is an organic material or a polymeric material selected from the group consisting of: poly (anthraquinone sulfides) (PAQS), lithium oxycarbide, 3,4,9, 10-perylenetetracarboxylic dianhydride (PTCDA), poly (anthraquinone sulfides), pyrene-4, 5,9, 10-tetraketone (PYT), polymer-bonded PYT, quinone (triazene), redox active organic materials, Tetracyanoquinodimethane (TCNQ), Tetracyanoethylene (TCNE), 2,3,6,7,10, 11-Hexamethoxytriphenylene (HMTP), poly (5-amino-1, 4-dihydroxyanthraquinone) (PADAQ), phosphazene disulfide polymers ([ (NPS)₂)₃]n), lithiated 1,4,5, 8-naphthalenetetraol formaldehyde polymers, Hexaazatrinaphthalene (HATN), hexaazatrinexabenzene hexaNitrile (HAT (CN)₆) 5-benzylidenehydantoin, isatin lithium salt, pyromellitic diimide lithium salt, tetrahydroxy-p-benzoquinone derivative (THQLi)₄) N, N ' -diphenyl-2, 3,5, 6-tetraone piperazine (PHP), N ' -diallyl-2, 3,5, 6-tetraone piperazine (AP), N ' -dipropyl-2, 3,5, 6-tetraone piperazine (PRP), thioether polymers, quinone compounds, 1, 4-benzoquinone, 5,7,12, 14-Pentacenetetraone (PT), 5-amino-2, 3-dihydro-1, 4-dihydroxyanthraquinone (ADDAQ), 5-amino-1, 4-dihydroxyanthraquinone (ADAQ), quinoid calixarenes (calixquinone), Li₄C₆O₆、Li₂C₆O₆、Li₆C₆O₆Or a combination thereof.

The thioether polymer is selected from poly [ methanetrinitrobenzylnitroamine-tetrakis (thiomethylene) ] (PMTTM), poly (2, 4-dithiopentene) (PDTP), a polymer containing poly (ethylene-1, 1,2, 2-tetrathiol) (PETT) as a main chain thioether polymer, a side chain thioether polymer having a main chain composed of conjugated aromatic moieties and having thioether side chains as side chains, poly (2-phenyl-1, 3-dithiolane) (PPDT), poly (1, 4-bis (1, 3-dithiolane-2-yl) benzene) (PDDTB), poly (tetrahydrobenzodithiophene) (PTHBDT), poly [1,2,4, 5-tetrakis (propylthio) benzene ] (PTKPTB), or poly [3,4 (ethylenedithio) thiophene ] (PEDTT).

In a preferred embodiment, the cathode active material is an organic material containing a phthalocyanine compound selected from the group consisting of: copper phthalocyanine, zinc phthalocyanine, tin phthalocyanine, iron phthalocyanine, lead phthalocyanine, nickel phthalocyanine, vanadyl phthalocyanine, fluorochrome phthalocyanine, magnesium phthalocyanine, manganese phthalocyanine, dilithium phthalocyanine, aluminum phthalocyanine chloride, cadmium phthalocyanine, chlorogallium phthalocyanine, cobalt phthalocyanine, silver phthalocyanine, metal-free phthalocyanines, chemical derivatives thereof, or combinations thereof.

In the lithium metal battery, the cathode active material composition is greater than 30mg/cm²(preferably greater than 40 mg/cm)²More preferably more than 45mg/cm²And most preferably greater than 50mg/cm²) And/or wherein the first conductive foam structure has a thickness of no less than 300 μm (preferably no less than 400 μm, more preferably no less than 500 μm, and may be greater than 600 μm).

Drawings

Fig. 1(a) a schematic of a prior art lithium ion battery cell comprised of an anode current collector, one or two anode active material layers (e.g., thin Si coatings) coated on both major surfaces of the anode current collector, a porous separator and electrolyte, one or two cathode electrode layers (e.g., sulfur layers), and a cathode current collector;

FIG. 1(B) schematic of a prior art lithium ion battery in which the electrode layers are made of active materials (e.g., graphite or tin oxide particles in the anode layer or LiCoO in the cathode layer)₂) Of the conductive additive (not shown), and a resin binder (not shown).

Fig. 1(C) is a schematic of a lithium ion battery cell of the invention comprising a quasi-solid anode (consisting of anode active material particles and conductive filaments mixed or dispersed directly in an electrolyte), a porous separator, and a quasi-solid cathode (consisting of cathode active material particles and conductive filaments mixed or dispersed directly in an electrolyte). In this embodiment, no resin binder is required.

Fig. 1(D) is a schematic of a lithium metal battery cell of the invention comprising an anode (comprising a lithium metal layer deposited on the surface of a Cu foil), a porous separator, and a quasi-solid cathode (consisting of particles of a cathode active material and conductive filaments mixed or dispersed directly in an electrolyte). In this embodiment, no resin binder is required.

FIG. 2(A) vapor pressure ratio data (p) as a function of sodium salt molecular ratio x (NaTFSI/DOL)_sWhere/p is the vapor pressure of the solution/vapor pressure of the solvent alone), and theoretical predictions based on classical Raoult's Law.

FIG. 2(B) vapor pressure ratio data (p) as a function of sodium salt molecular ratio x (NaTFSI/DME)_sP ═ vapor pressure of solution/vapor pressure of solvent alone), and theoretical predictions based on classical raoult's law.

FIG. 2(C) shows the molecular ratio x (NaPF) of sodium salt₆Vapor pressure ratio data (p) as a function of DOL_s(ii) vapor pressure of solution/vapor pressure of solvent alone) And theoretical predictions based on classical Raoult's law.

FIG. 2(D) molecular ratio x (NaTFSI/DOL, NaTFSI/DME, NaPF) as sodium salt₆Vapor pressure ratio data (p) as a function of DOL_sP ═ vapor pressure of solution/vapor pressure of solvent alone), and theoretical predictions based on classical raoult's law.

FIG. 3(A) a schematic of a close-packed highly ordered structure of a solid electrolyte;

FIG. 3(B) has a cation (e.g., Na)⁺) A schematic representation of a fully amorphous liquid electrolyte with a large free volume portion that can easily migrate through;

fig. 3(C) shows a random or amorphous structure of a quasi-solid electrolyte with solvent molecules separating salt species to create amorphous regions that facilitate migration of free (unclustered) cations.

FIG. 4(A) Na of electrolyte (e.g. NaTFSI salt/(DOL + DME) solvent) related to sodium salt molecular ratio x⁺Ion transfer number.

FIG. 4(B) Na of electrolyte (e.g. NaTFSI salt/(EMIMTFSI + DOL) solvent) related to sodium salt molecular ratio x⁺Ion transfer number.

FIG. 4(C) Na of electrolyte (e.g. NaTFSI salt/(EMIMTFSI + DME) solvent) related to sodium salt molecular ratio x⁺Ion transfer number.

FIG. 4(D) Na in various electrolytes (as in FIGS. 6 to 8) in relation to the sodium salt molecular ratio x⁺Ion transfer number.

Fig. 5 is a schematic diagram of a common process for producing expanded graphite, expanded graphite flakes (thickness >100nm) and graphene sheets (thickness <100nm, more typically <10nm, and can be as thin as 0.34 nm).

Fig. 6(a) conductivity (percolation behavior) of conductive filaments in a quasi-solid electrode plotted as a function of volume fraction of conductive filaments (carbon nanofibers).

Fig. 6(B) conductivity (percolation behavior) of conductive filaments in a quasi-solid electrode plotted as a function of volume fraction of conductive filaments (reduced graphene oxide sheets).

Fig. 7 a la-go plot (gravimetric power density versus energy density) for a lithium ion battery cell containing graphite particles as the anode active material and carbon-coated LFP particles as the cathode active material. Three of the 4 data curves are for cells prepared according to embodiments of the invention, while the remaining one is a cell prepared by conventional electrode paste coating (roll coating).

FIG. 8 Ragong plots (gravimetric power density vs. gravimetric energy density) for three cells, each containing graphene-surrounded Si nanoparticles as anode active material and LiCoO₂The nanoparticles serve as a cathode active material. Experimental data were obtained from Li-ion battery cells prepared by the method of the invention (following sequences S1 and S3) and Li-ion battery cells prepared by conventional electrode slurry coating.

FIG. 9 contains lithium foil as the anode active material, dilithium rhodizonate (Li)₂C₆O₆) As a cathode active material and a lithium salt (LiPF)₆) Plot of Ragong for lithium metal batteries with PC/DEC as organic electrolyte. The data are lithium metal cells prepared by the inventive method (sequences S2 and S3 with 2 different salt concentrations) and lithium metal cells prepared by conventional electrode slurry coating.

FIG. 10 Ragong plots for two sodium ion capacitors, each containing pre-sodiated hard carbon particles as an anode active material and graphene sheets as a cathode active material; one cell has an anode prepared by a conventional slurry coating process and the other cell has a quasi-solid anode prepared according to the method of the invention.

Detailed Description

The present invention is directed to a method of producing a lithium or sodium battery that exhibits an exceptionally high volumetric energy density that has never been previously achieved. The battery may be a primary battery, but is preferably a secondary battery selected from a lithium ion battery, a lithium metal secondary battery (for example, using lithium metal as an anode active material), a sodium ion battery, a sodium metal battery, a lithium ion capacitor, or a sodium ion capacitor. Batteries are based on aqueous electrolytes, non-aqueous or organic electrolytes, ionic liquid electrolytes, or mixtures of organic liquids and ions. Preferably, the electrolyte is a "quasi-solid electrolyte" containing a high concentration of lithium or sodium salts in a liquid solvent to the extent: it behaves like a solid but is deformable even when the desired amount of conductive filaments and active material are added to the electrolyte (hence the term "deformable quasi-solid electrode material"). The shape of the lithium battery may be cylindrical, square, button-like, etc. The present invention is not limited to any battery shape or configuration.

For convenience, selected materials will be used, such as lithium iron phosphate (LFP), vanadium oxide (V)_xO_y) Dilithium rhodizonate (Li)₂C₆O₆) And copper phthalocyanine (CuPc) as an illustrative example of the cathode active material, and graphite, hard carbon, SnO, Co₃O₄And Si particles as examples of the anode active material. These should not be construed as limiting the scope of the invention.

As shown in fig. 1(a), prior art lithium battery cells are typically constructed of an anode current collector (e.g., Cu foil), an anode electrode or anode active material layer (e.g., Li metal foil or a pre-lithiated Si coating deposited on one or both sides of the Cu foil), a porous separator and/or electrolyte component, a cathode electrode or cathode active material layer (or two cathode active material layers coated on both sides of the Al foil), and a cathode current collector (e.g., Al foil).

In a more common prior art cell construction (fig. 1(B)), the anode layer is composed of particles of anode active material (e.g., graphite, hard carbon, or Si), conductive additives (e.g., carbon black particles), and a resin binder (e.g., SBR or PVDF). The cathode layer is composed of cathode active material particles (e.g., LFP particles), a conductive additive (e.g., carbon black particles), and a resin binder (e.g., PVDF). Both the anode and cathode layers are typically up to 100-200 μm thick to produce approximately sufficient current per unit electrode area. This thickness range is considered an industry-accepted constraint in which battery designers typically work. This thickness constraint is due to several reasons: (a) existing battery electrode coating machines are not equipped to coat either too thin or too thick electrode layers; (b) thinner layers are preferred based on considerations of reduced lithium ion diffusion path length; but a layer that is too thin (e.g., <100 μm) does not contain a sufficient amount of active lithium storage material (and therefore, insufficient current output); (c) thicker electrodes tend to delaminate or crack when dried or handled after roll coating; and (d) all inactive material layers (e.g., current collectors and separators) in the battery cell must be kept to a minimum in order to achieve minimum non-contributing weight and maximum lithium storage capacity, and thus maximum energy density (Wk/kg or Wh/L of the cell).

In a less common cell configuration, as shown in fig. 1(a), the anode active material (e.g., Si coating) or cathode active material (e.g., lithium transition metal oxide) is deposited in thin film form directly on a current collector such as a copper or Al foil. However, such thin film structures with extremely small thickness dimension (typically much less than 500nm, often necessarily thinner than 100nm) mean that only a small amount of active material can be incorporated into the electrode (given the same electrode or current collector surface area), providing low total lithium storage capacity and low lithium storage capacity per unit electrode surface area. Such films must have a thickness of less than 100nm to be more resistant to cycle-induced cracking (for the anode) or to facilitate full utilization of the cathode active material. This constraint further reduces the total lithium storage capacity and lithium storage capacity per unit electrode surface area. Such thin film batteries have a very limited range of applications.

On the anode side, Si layers thicker than 100nm have been found to exhibit poor resistance to cracking during the cell charge/discharge cycles. The fragmentation of the Si layer requires only a few cycles. On the cathode side, a sputtered layer of lithium metal oxide thicker than 100nm does not allow lithium ions to sufficiently penetrate and reach the entire cathode layer, resulting in poor utilization of the cathode active material. A desirable electrode thickness is at least 100 μm, with individual active material coatings or particles having a size desirably less than 100 nm. Therefore, these thin film electrodes deposited directly on the current collector (where the thickness is <100nm) are three (3) orders of magnitude lower than the desired thickness. As a further problem, all cathode active materials are not capable of conducting both electrons and lithium ions. A large layer thickness means an excessively high internal resistance and poor active material utilization. Sodium batteries have similar problems.

In other words, when dealing with the design and selection of cathode or anode active materials in terms of material type, size, electrode layer thickness, and active material mass loading, there are several conflicting factors that must be considered simultaneously. To date, any of the prior art teachings have not provided an effective solution to these often contradictory problems. We have solved these challenging problems that have plagued cell designers and electrochemical houses for more than 30 years by developing new methods of producing lithium or sodium cells as disclosed herein.

Prior art lithium battery cells are typically made by a process comprising the steps of: (a) the first step is to mix particles of the anode active material (e.g., Si nanoparticles or mesocarbon microbeads, MCMB), conductive fillers (e.g., graphite flakes), a resin binder (e.g., PVDF) in a solvent (e.g., NMP) to form an anode slurry. On a separate basis, cathode active material particles (e.g., LFP particles), a conductive filler (e.g., acetylene black), a resin binder (e.g., PVDF), and a solvent (e.g., NMP) are mixed and dispersed to form a cathode slurry. (b) The second step involves coating the anode slurry onto one or both major surfaces of an anode current collector (e.g., Cu foil), drying the coated layer by evaporating the solvent (e.g., NMP) to form a dried anode electrode coated on the Cu foil. Similarly, the cathode slurry was coated and dried to form a dried cathode electrode coated on Al foil. Slurry coating is usually carried out in a roll-to-roll manner in the actual manufacturing situation; (c) the third step involves laminating the anode/Cu foil, porous separator layer and cathode/Al foil together to form a 3-or 5-layer assembly, which is cut and slit to the desired size and stacked to form a rectangular structure (as an example of a shape) or wound into a cylindrical cell structure. (d) The rectangular or cylindrical laminate structure is then enclosed in an aluminum plastic laminate envelope or steel housing. (e) A liquid electrolyte is then injected into the laminate structure to produce a lithium battery cell.

There are several serious problems associated with this method and the resulting lithium battery cell:

1) it is very difficult to produce electrode layers (anode or cathode layers) thicker than 200 μm. There are several reasons for this to occur. Electrodes of 100-200 μm thickness typically require heating zones of 30-50 meters in length in a slurry coating facility, which is too time consuming, too energy consuming, and not cost effective. For some electrode active materials, such as metal oxide particles, it is not possible to produce electrodes of good structural integrity thicker than 100 μm on a continuous basis in a practical manufacturing environment. The resulting electrode is very fragile and brittle. Thicker electrodes have a high tendency to delaminate and crack.

2) With conventional approaches, as depicted in fig. 1(a), the actual mass loading of the electrode and the apparent density of the active material are too low to be achieved>A gravimetric energy density of 200 Wh/kg. In most cases, the mass loading (areal density) of the anode active material of the electrode is significantly less than 25mg/cm²And even for relatively large graphite particles, the apparent bulk or tap density of the active material is typically less than 1.2g/cm³. The cathode active material mass loading (areal density) of the electrode is significantly less than 45mg/cm for lithium metal oxide type inorganic materials²And less than 15mg/cm for organic or polymeric materials². In addition, there are so many other inactive materials (e.g., conductive additives and resin binders) that the additional weight and volume of the electrode is increased without contributing to the cell capacity. These low areal and bulk densities result in relatively low gravimetric and low volumetric energy densities.

3) The conventional method requires that electrode active materials (an anode active material and a cathode active material) be dispersed in a liquid solvent (e.g., NMP) to manufacture a slurry, and when applied onto a current collector surface, the liquid solvent must be removed to dry the electrode layer. Once the anode and cathode layers are laminated together with the separator layer and encapsulated in a housing to produce a supercapacitor cell, a liquid electrolyte is then injected into the cell. In practice, the two electrodes are wetted, then the electrodes are dried and finally they are wetted again. This wet-dry-wet process does not sound like a good process at all.

4) Current lithium ion batteries still suffer from relatively low gravimetric energy density and relatively low volumetric energy density. Commercially available lithium ion batteries exhibit a gravimetric energy density of approximately 150-.

In the literature, energy density data reported based on active material weight or electrode weight alone cannot be directly translated into energy density of an actual battery cell or device. The "non-contributing weight" or weight of other device components (adhesives, conductive additives, current collectors, separators, electrolytes, and encapsulants) must also be taken into account. Conventional production methods result in a weight proportion of anode active material (e.g., graphite or carbon) in lithium ion batteries typically from 12% to 17%, and cathode active material (e.g., LiMn)₂O₄) From 20 to 35% by weight.

The present invention provides a method of producing a lithium or sodium battery cell having high electrode thickness, high active material mass loading, low non-contributing weight and volume, high capacity, and high energy density.

In certain embodiments, the method comprises:

(a) combining an amount of active material (anode active material or cathode active material), an amount of electrolyte, and a conductive additive to form a deformable and conductive electrode material, wherein the conductive additive containing conductive filaments forms a 3D network of electron conducting pathways; (these conductive filaments, such as carbon nanotubes and graphene sheets, are a large number of randomly aggregated filaments prior to mixing with the particles of active material and electrolyte

(b) Forming the electrode material as a quasi-solid electrode, wherein the forming step comprises deforming the electrode material into an electrode shape without interrupting the 3D network of electron conduction pathways, thereby causing the electrode to remain no less than 10^{- 6}S/cm (preferably not less than 10)^-5S/cm, more preferably not less than 10^-4S/cm, more preferablyNot less than 10^-3S/cm, still more preferably and typically not less than 10^-2S/cm, even more typically and preferably not less than 10^-1An electrical conductivity of S/cm, and further more typically and preferably not less than 1S/cm; up to 300S/cm is observed);

(c) forming a second electrode (which may be a quasi-solid electrode or a conventional electrode); and is

(d) Forming an alkali metal cell by combining the quasi-solid electrode and the second electrode, the alkali metal cell having an ion-conducting membrane disposed between the two electrodes.

As shown in fig. 1(C), one preferred embodiment of the invention is an alkali metal ion cell having a conductive quasi-solid anode 236, a conductive quasi-solid cathode 238, and a porous separator 240 (or ion permeable membrane) that electronically separates the anode and cathode. These three components are typically enclosed in a protective housing (not shown) that typically has an anode tab (terminal) connected to the anode and a cathode tab (terminal) connected to the cathode. These tabs are used to connect to an external load (e.g., a battery-powered electronic device). In this particular embodiment, the quasi-solid anode 236 contains an anode active material (e.g., Si particles, not shown in FIG. 1 (C)), an electrolyte phase (typically containing a lithium or sodium salt dissolved in a solvent; also not shown in FIG. 1 (C)), and a conductive additive (containing conductive filaments) that forms a 3D network 244 of electron conducting pathways. Similarly, the quasi-solid cathode contains a cathode active material, an electrolyte, and a conductive additive (containing conductive filaments) that forms a 3D network 242 of electron conducting pathways.

Another preferred embodiment of the invention, as shown in fig. 1(D), is an alkali metal cell with an anode comprised of a lithium or sodium metal coating/foil 282 deposited/attached to a current collector 280 (e.g., a Cu foil), a quasi-solid cathode 284, and a separator or ion conducting membrane 282. The quasi-solid cathode 284 contains a cathode active material 272 (e.g., LiCoO)₂Particles of (b), an electrolyte phase 274 (typically containing a lithium or sodium salt dissolved in a solvent), and a conductive additive phase (containing conductive filaments) forming a 3D network 270 of electron conducting pathways. The invention also includes lithium ionA sub-capacitor and a sodium ion capacitor.

The electrolyte is preferably a quasi-solid electrolyte containing a lithium salt or a sodium salt dissolved in a liquid solvent, the salt concentration being not less than 2.5M, preferably more than 3M, more preferably more than 3.5M, further preferably more than 5M, still more preferably more than 7M, and even more preferably more than 10M. In certain embodiments, the electrolyte is a quasi-solid electrolyte containing a lithium or sodium salt dissolved in a liquid solvent, with a salt concentration from 3.0M to 14M. The selection of the lithium or sodium salt and the liquid solvent is discussed further in the following section.

Both the quasi-solid anode and the quasi-solid cathode preferably have a thickness greater than 200 μm (preferably greater than 300 μm, more preferably greater than 400 μm, further preferably greater than 500 μm, still more preferably greater than 800 μm, further preferably greater than 1mm, and may be greater than 5mm, 1cm, or thicker²(more typically and preferably not less than 25 mg/cm)²And more preferably not less than 30mg/cm²) Electrode active material loading. For inorganic materials as the cathode active material, the cathode active material composition is not less than 45mg/cm²(typically and preferably greater than 50 mg/cm)²And more preferably greater than 60mg/cm²) Electrode active material mass loading (not less than 25mg/cm for organic or polymeric cathode active materials)²)。

In such configurations (fig. 1(C) to 1(D)), the electrons need only travel a short distance (e.g., a few microns) before they are collected by the conductive filaments that make up the 3D network of electron conduction pathways and are present everywhere in the entire quasi-solid electrode (anode or cathode). In addition, all electrode active material particles are pre-dispersed in the liquid electrolyte (no wetting problem), eliminating the presence of dry pockets typically found in electrodes prepared by conventional methods of wet coating, drying, packaging and electrolyte injection. Thus, the process or method of the present invention has a completely unexpected advantage over conventional battery cell production methods.

These conductive filaments (e.g., carbon nanotubes and graphene sheets) as supplied are initially a large number of randomly aggregated filaments before being mixed with the particles of active material and electrolyte. The mixing procedure involves dispersing these conductive filaments in a highly viscous electrolyte containing particles of the active material. This is not a trivial task as one might think. It has been known that the dispersion of nanomaterials (particularly nanofilament materials such as carbon nanotubes, carbon nanofibers, and graphene sheets) in highly flowable (non-viscous) liquids is difficult, not to mention in highly viscous quasi-solids, such as electrolytes containing high loadings of active materials (e.g., solid particles such as Si nanoparticles for anodes and lithium cobalt oxide for cathodes). In some preferred embodiments, this problem is further exacerbated by the following viewpoints: the electrolyte itself is a quasi-solid electrolyte containing a high concentration of lithium or sodium salts in a solvent.

In some preferred embodiments, the electrolyte contains an alkali metal salt (lithium salt and/or sodium salt) dissolved in an organic or ionic liquid solvent, wherein the alkali metal salt molecular ratio is sufficiently high such that the electrolyte exhibits a vapor pressure (when measured at 20 ℃) that is less than 0.01kPa or less than 0.6 (60%) of the vapor pressure of the solvent alone, a flash point that is at least 20 degrees celsius higher than the flash point of the first organic liquid solvent alone (when no lithium salt is present), a flash point that is higher than 150 ℃, or no detectable flash point at all.

Of most surprising and great scientific and technical importance is our finding that: the flammability of any volatile organic solvent can be effectively suppressed provided that a sufficiently high amount of alkali metal salt is added to and dissolved in the organic solvent to form a solid-like or quasi-solid electrolyte. Generally, such quasi-solid electrolytes exhibit a vapor pressure of less than 0.01kPa and often less than 0.001kPa (when measured at 20 ℃) and less than 0.1kPa and often less than 0.01kPa (when measured at 100 ℃). (the vapor pressure of the corresponding pure solvent in which no alkali metal salt is dissolved is typically significantly higher.) in many cases, the vapor molecules are actually too few to be detected.

Very important observations are: the high solubility of alkali metal salts (macromolecular ratio or mole fraction of alkali metal salts, typically >0.2, more typically >0.3, and often >0.4 or even >0.5) in otherwise highly volatile solvents can significantly reduce the amount of volatile solvent molecules that can escape into the vapor phase under thermodynamic equilibrium conditions. In many cases, this effectively prevents flammable solvent gas molecules from initiating the flame, even at extremely high temperatures (e.g., using a torch). The flash point of the quasi-solid electrolyte is typically at least 20 degrees (often >50 or >100 degrees) higher than the flash point of the pure organic solvent alone. In most cases, the flash point is above 150 ℃ or no flash point can be detected. The electrolyte will not ignite. Furthermore, any accidental fire does not last longer than a few seconds. This is a very important finding in view of the fire and explosion concerns that have been a major obstacle to the widespread acceptance of battery powered electric vehicles. This new technology can help significantly accelerate the rise of the live EV industry.

From a basic chemical principle point of view, adding solute molecules to a liquid increases the boiling temperature of the liquid and lowers its vapor pressure and freezing temperature. These phenomena, as well as osmosis, depend only on solute concentration, not on its type, and are referred to as the colligative property of the solution. The initial Raoult law provides the vapor pressure (p) of a solution_s) Relationship between the ratio to the vapor pressure (p) of the pure liquid and the mole fraction (x) of the solute:

p_s/p＝e^-xequation (1a)

For dilute solutions, x<<1, and thus e^-x1-x. Thus, for the species case of low solute mole fraction, the more common form of raoult's law is obtained:

p_s1-x equation (1b)

To determine whether classical raoult's law can be used to predict the vapor pressure of highly concentrated electrolytes, we continued to investigate a wide variety of alkali metal salt/organic solvent combinations. Some examples of our findings are summarized in fig. 2(a) to 2(D), where experiment p is taken for several salt/solvent combinations_sThe value of/p is taken as the molecular ratio (molar fraction)Number, x) is plotted. A curve based on classical raoult's law, equation (1a), was also plotted for comparison purposes. Obviously, for all types of electrolytes, p_sThe value of/p follows Raoult's law prediction until the mole fraction x reaches about 0.2, beyond which the vapor pressure rapidly drops to essentially zero (almost undetectable). When the vapor pressure is below the threshold, no flame will be initiated, and the present invention provides an excellent platform material chemistry that effectively suppresses flame initiation.

Although scientific deviations from Raoult's law are not uncommon, this type of p has never been observed for any binary solution system_sThe curve/p. In particular, for safety reasons, no reports have been made regarding ultra-high concentration battery electrolytes (having a high molecular fraction, for example>0.2 or>0.3 alkali metal salt) was investigated. This is indeed unexpected and of great technical and scientific significance.

We have further unexpectedly found that: the presence of a 3D network of electron conducting pathways composed of conductive filaments serves to further reduce the threshold concentration of alkali metal salt required for critical vapor pressure suppression.

Another surprising element of the present invention is the following: we are able to dissolve high concentrations of alkali metal salts in almost every type of commonly used battery grade organic solvent to form quasi-solid electrolytes suitable for rechargeable alkali metal batteries. Expressed in more readily recognized terms, the concentration is typically greater than 2.5M (moles/liter), more typically and preferably greater than 3.5M, still more typically and preferably greater than 5M, still more preferably greater than 7M, and most preferably greater than 10M. In the case where the salt concentration is not less than 2.5M, the electrolyte is no longer a liquid electrolyte; rather, it is a quasi-solid electrolyte. Such high concentrations of alkali metal salts in solvents are generally considered impossible, nor desirable, in the field of lithium or sodium batteries. However, we found that these quasi-solid electrolytes are surprisingly good electrolytes for both lithium and sodium batteries in terms of significantly improved safety (non-flammability), improved energy density and improved power density.

Generally, the vapor pressure of a solution cannot be directly and straightforwardly predicted from the concentration value in units of M (moles/liter). Rather, for alkali metal salts, the molecular ratio x in raoult's law is the sum of the mole fractions of positive and negative ions, which is proportional to the degree of dissociation of the metal salt in a particular solvent at a given temperature. The mols/liter concentration does not provide sufficient information to predict vapor pressure.

In general, it is not possible to achieve such high concentrations of alkali metal salts (e.g., x ═ 0.3 to 0.7) in the organic solvents used in the battery electrolyte, particularly when network-forming conductive filaments and/or active material particles are also present. Through extensive and intensive research, we further found that: the apparent solubility of an alkali metal salt in a particular solvent can be significantly increased if first (a) a highly volatile co-solvent is used to increase the amount of alkali metal salt dissolved in the solvent mixture, and then (b) once the dissolution procedure is complete, the volatile co-solvent is partially or completely removed. Quite unexpectedly, even if the solution would be highly supersaturated, removal of the co-solvent typically does not result in precipitation or crystallization of the alkali metal salt from the solution. This novel and unique approach appears to result in a material state in which most solvent molecules are captured or held in place by non-volatile alkali metal salt ions (in fact, lithium/sodium salts behave as solids). As a result, very few volatile solvent molecules are able to escape into the vapor phase, and as a result, there are very few "flammable" gas molecules to help initiate or sustain a flame. In the prior art of Na, K or Li metal batteries, this is not technically suggested to be possible or feasible.

Furthermore, one skilled in the art of chemistry or material science would expect that such high salt concentrations should cause the electrolyte to behave like a solid with a very high viscosity, and therefore, the electrolyte should not be suitable for rapid diffusion of alkali metal ions therein. Thus, one skilled in the art would expect that an alkali metal battery containing such a solid-like electrolyte would not and cannot exhibit high capacity (i.e., electricity) at high charge-discharge rates or under high current density conditionsThe cell should have poor rate capability). Contrary to these expectations of the skilled person or even of a superior skilled person, all alkali metal cells containing such quasi-solid electrolytes impart a high energy density and a high power density, thereby achieving a long cycle life. It appears that quasi-solid electrolytes as invented and disclosed herein facilitate easy alkali metal ion transport. This unexpected finding may be due to two main factors: one associated with the internal structure of the electrolyte and the other with high Na⁺Or Li⁺Ion Transfer Number (TN), as will be further explained in later sections of this specification.

Without wishing to be bound by theory, the internal structure of three fundamentally different types of electrolytes can be visualized by reference to fig. 3(a) to 3 (C). Fig. 3(a) schematically shows a close-packed highly ordered structure of a typical solid electrolyte, in which there is little free volume for diffusion of alkali metal ions. Any migration of ions in such a crystal structure is very difficult, resulting in a very low diffusion coefficient (10)^-16To 10^-12cm²S) and extremely low ionic conductivity (typically from 10)^-7S/cm to 10^-4S/cm). In contrast, as schematically shown in fig. 3(B), the internal structure of the liquid electrolyte is completely amorphous, having cations (e.g., or Li)⁺Or Na⁺) Large free volume fraction that can easily migrate through, resulting in a high diffusion coefficient (10)^-8To 10^-6cm²S) and high ionic conductivity (typically from 10)^-3S/cm to 10^-2S/cm). However, liquid electrolytes containing low concentrations of alkali metal salts are also flammable and prone to dendrite formation, creating a fire and explosion hazard. Schematically shown in fig. 3(C) is the random or amorphous structure of a quasi-solid electrolyte with solvent molecules that separate salt species to create amorphous regions that facilitate migration of free (unclustered) cations. Such a structure is suitable for achieving high ionic conductivity values (typically 10)^-4S/cm to 8x10^-3S/cm) but remain nonflammable. There are relatively few solvent molecules and these molecules are overwhelmingly abundantThe salt species and the network of conductive filaments remain (prevent evaporation).

As a second factor, we have found that quasi-solid electrolytes provide a TN greater than 0.3 (typically in the range from 0.4 to 0.8), while all lower concentrations of electrolytes (e.g., all lower concentrations used in all current Li-ion and Na-ion cells) are present<2.0M; typical values in most cases 1M) are 0.1-0.2. As indicated in FIGS. 4(A) to 4(D), Na in the low salt concentration electrolyte⁺The ion transfer number decreases with increasing concentration from 0 to 0.2-0.35. However, above the molecular ratio of x-0.2-0.35, the number of transfers increased with increasing salt concentration, indicating Na⁺Or Li⁺Fundamental changes in ion transport mechanisms. Also, without wishing to be bound by theory, we want to use Na⁺The ions provide the following scientifically reasonable explanation as an example (similar explanations apply to Li)⁺Ion): when Na is present⁺Electrolytes with ions at low salt concentrations (e.g. x)<0.2) in each Na⁺The ions drag one or more solvated molecules with them. This cooperative migration of clusters of charged species can be further hindered if the fluid viscosity increases (i.e., when more salt is added to the solvent).

Fortunately, when ultra-high concentrations of Na salt (e.g., having x) are present>0.3) time, Na⁺The number of ions may greatly exceed the available solvating species or solvent molecules that might otherwise cluster the lithium ions, forming multi-member complex species and slowing Na⁺And (4) a diffusion process of ions. The high Na content⁺The ion concentration makes it possible to have more "free Na⁺Ions "(those that act alone without clustering), thereby providing high Na⁺Number of transfer (thus providing easy Na)⁺Transmission). In other words, the sodium ion transport mechanism changes from a mechanism dominated by polyionic complexes (with larger hydrodynamic radius) to having a large amount of free Na available⁺Single-ion dominated mechanism of ions (with smaller hydrodynamic radius). The observation was further confirmed to be Na⁺The ions can be operated on quasi-solid electrolytes without damaging Na goldBelongs to the multiplying power performance of the battery cell. However, these highly concentrated electrolytes are nonflammable and safe. In any of the previous reports, these combined features and advantages for battery applications have never been taught or even slightly implied. The theoretical aspects of the ion transfer number of a quasi-solid electrolyte are now presented below:

the ionic conductivity of lithium or sodium ions is an important factor to consider when selecting an electrolyte system for a battery. Na (Na)⁺The ionic conductivity of the ions in the organic liquid based electrolyte is about 10^-3-10^-2S/cm and an ionic conductivity in solid electrolytes typically in the range of from 10^-7-10^-4S/cm. Due to the low ionic conductivity, solid-state electrolytes have not been used to any significant extent in any battery system. This is unfortunately due to the inability of the solid-state electrolyte to resist dendrite penetration in alkali metal secondary batteries. In contrast, the ionic conductivity of our quasi-solid electrolytes is typically from 10^-4-8x 10^-3In the range of S/cm, sufficient for use in rechargeable batteries.

The ionic mobility or diffusion coefficient is not the only important transport parameter for the battery electrolyte. The individual transfer numbers of cations and anions are also important. For example, when a viscous liquid is used as an electrolyte in an alkali metal battery, the ion mobility is reduced. Therefore, in order to achieve high ion conductivity, a high transfer number of alkali metal ions in the electrolyte is required.

Investigation of only one type of cation (i.e., Na) by AC impedance spectroscopy and pulsed field gradient NMR techniques⁺) And one type of anion, plus liquid solvent or a mixture of two liquid solvents. The ac impedance provides information about the total ionic conductivity, and NMR allows the determination of the individual self-diffusion coefficients of cations and anions. Generally, the self-diffusion coefficient of cations is slightly higher than that of anions. It has been found that the Haven ratio obtained from the diffusion coefficient and the total ionic conductivity is typically in the range from 1.3 to 2, indicating ion pairs or ion complexes (e.g. Na)⁺-a solventClusters of chemical molecules) is an important feature in electrolytes containing low salt concentrations.

The situation becomes more complicated when two different alkali metal salts or one ionic liquid (as alkali metal salts or as liquid solvent) are added to the electrolyte, resulting in a solution with at least 3 or 4 types of ions. In this case, for example, it is advantageous to use alkali metal salts which contain the same anions as in the solvated ionic liquid, since the amount of soluble alkali metal salts is higher than in mixtures with different anions. Therefore, the next logical question to ask is whether Na can be improved by dissolving more sodium (or lithium) salt in the liquid solvent⁺(or Li)⁺) The number of transfers.

Total ionic conductivity σ of the Triionic liquid mixture_dcThe relationship to the individual diffusion coefficient Di of an ion can be given by the Nernst-Einstein equation: sigma_dc＝(e²/k_BTH_R)[(N_Na ⁺)(D_Na ⁺)+(N_E ⁺)(D_E ⁺)+(N_B ^-)(D_B ^-)]Equation (2)

Here, e and k_BIndicating the elementary charge and the boltzmann constant, respectively, and N_iIs a single ion (Na)⁺、Li⁺、ClO₄ ^-Etc.) of the same. Haven ratio H_RThe cross-correlation between different types of ion movement is explained.

Simple ionic liquids having only one type of cation and anion are characterized by Haven ratios typically in the range from 1.3 to 2.0. A Haven ratio greater than 1 indicates that ions of different charges preferentially move in the same direction (i.e., the ions are transported in pairs or clusters). Evidence of such ion pairs can be found using raman spectra of various electrolytes. The value of the Haven ratio in the tri-ionic mixture ranges from 1.6 to 2.0. In contrast to electrolytes with x ═ 0, H_RA slightly higher value indicates more pronounced pair formation in the mixture.

For the same mixture, the total ionic conductivity of the mixture decreases with increasing alkali metal salt content x. This conductivity drop is directly related to the drop in the individual self-diffusion coefficients of all ions. Our studies on different mixtures of ionic liquids and alkali metal salts show that the viscosity increases with increasing salt content x. These findings indicate that the addition of alkali metal salts results in stronger ionic bonds in the liquid mixture, which slows down liquid kinetics. This is probably due to the fact that the coulomb interaction between small sodium (or lithium) ions and anions is stronger than that between larger organic cations and anions. Therefore, the decrease in ion conductivity with an increase in the alkali metal salt content x is not due to a decrease in the number density of mobile ions but due to a decrease in the mobility of ions.

To analyze the individual contributions of cations and anions to the overall ionic conductivity of the mixture, the apparent transfer number t can be defined by_i：

t_i＝N_iDi/(ΣN_iDi) equation (3)

For example, in a mixture of N-butyl-N-methyl-pyrrolidinium bis (trifluoromethanesulfonyl) imide (BMP-TFSI) and sodium bis (trifluoromethanesulfonyl) imide (Na-TFSI) (containing Na⁺、BMP⁺And TFSI^-Ion), apparent number of lithium transfer t_LiIncreases with increasing Na-TFSI content; at x ═ 0.34, t_Na0.242 (comparative x)<T at 0.2_Na<0.1)，D_Na≈0.7D_TFSIAnd D is_BMP≈1.6D_TFSI. Apparent Na in the mixture⁺The main reason for the higher number of transfers is Na⁺The number density of ions is higher.

To further increase the sodium transfer number in such mixtures, the number density and/or diffusion coefficient of the sodium ions must be further increased relative to other ions. Will expect Na⁺Further increase in ion number density is very challenging, as the mixture will tend to salt crystallization or precipitation at high Na salt content. The present invention overcomes this challenge. We have surprisingly observed that the addition of very small proportions of highly volatile organic liquids (e.g. ether-based solvents) can significantly enhance certain Na or LiSolubility limits of salts in high viscosity organic liquids (e.g. VC) or ionic liquids (e.g. typically from x)<0.2 to x>0.3-0.6, or typically from 1M to>5M). This can be achieved with ratios of ionic liquid (or viscous organic liquid) to volatile organic solvent as high as 10:1, thus keeping the volatile solvent content to a minimum and minimizing the potential flammability of the electrolyte.

The ion diffusion coefficient depends on the effective radius of the diffusing entity, as measured in pulsed field gradient NMR (PFG-NMR) experiments. Due to Na⁺Ions and TFSI^-Strong interaction between ions, Na⁺Ions can form [ Na (TFSI)_n+1]^n-A complex compound. Coordination numbers of alkali metal ions up to n +1 ═ 4 have been observed. The coordination number determines the effective hydrodynamic radius of the complex and thus the diffusion coefficient in the liquid mixture. Stokes-Einstein equation Di ═ k_BT/(cπηr_i) Can be used to calculate its effective hydrodynamic radius ri from the diffusion coefficient Di of the diffusion entity. The constant c varies between 4 and 6 depending on the shape of the diffusing entity. Comparison of the effective hydrodynamic radii of cations and anions in ionic liquids with their van der waals radii reveals that cations generally have lower c values than anions. In the case of the EMI-TFSI/Na-TFSI mixture, the hydrodynamic radius of Na is in the range from 0.9 to 1.3 nm. This approximation is [ Na (TFSI)₂]^-And [ Na (TFSI)₃]^2-The van der waals radius of the complex. In the case of BMP-TFSI/Na-TFSI mixtures with x ═ 0.34, under the assumption that r is_BMP0.55nm and against BMP⁺The effective hydrodynamic radius of the diffusing sodium complex is r, as is the c value of the diffusing Na complex_Na＝(D_BMP/D_Na)r_BMP1.3 nm. The r is_NaThe values show that in mixtures containing low salt concentrations, the sodium coordination number in the diffusion complex is at least 2.

Due to TFSI^-The number of ions is not high enough to form significant amounts of [ Na (TFSI)₃]^2-Complexes, therefore most of the sodium ions should be replaced with [ Na (TFSI) ]₂]^-The form of the complex diffuses. On the other hand, if higher Na salt concentrations are achieved without crystallization (e.g. in our quasi-solid electrolyte), the mixture should contain a considerable amount of neutral Na (tfsi)]Complexes of small size (r)_[Na(TFSI)]0.5nm) and should have a higher diffusivity. Thus, a higher salt concentration will not only increase the number density of sodium ions, but will also result in a higher diffusion coefficient for diffusing the sodium complex relative to the organic cation. The above analysis applies to electrolytes containing organic or ionic liquid solvents as well as both lithium and sodium ions. In all cases, when the alkali metal salt concentration is above the threshold, as the concentration is further increased, an increasing number of free or unclustered alkali metal ions will be moved between the anode and the cathode, thereby providing a sufficient amount of alkali metal ions needed for intercalation/deintercalation or chemical reactions at the cathode and anode.

In addition to the non-flammability and high alkali metal ion transfer number as discussed above, there are several other benefits to using the quasi-solid electrolyte of the present invention. For example, quasi-solid electrolytes can significantly enhance the cycling and safety performance of rechargeable alkali metal batteries by effectively inhibiting dendrite growth. It is generally believed that dendrites begin to grow in the non-aqueous liquid electrolyte when the anions are depleted near the electrode where plating occurs. In ultra-high concentration electrolytes, there are a large number of anions to retain cations (Li) near the metallic sodium anode⁺Or Na⁺) And anions. In addition, the space charge generated by anion depletion is extremely small, which is detrimental to dendrite growth. In addition, the quasi-solid electrolyte provides a large amount of available sodium ion flux due to an ultra-high Na salt concentration and a high Na ion transfer number, and improves the sodium ion mass transfer rate between the electrolyte and the sodium electrode, thereby enhancing the deposition uniformity and dissolution of sodium during charge/discharge. In addition, the locally high viscosity caused by the high concentration will increase the pressure from the electrolyte to inhibit dendrite growth, potentially resulting in a more uniform deposition on the anode surface. The high viscosity may also limit anion convection near the deposition area, thereby promoting more uniformity of sodium ionsAnd (4) depositing. The same reasoning applies to lithium metal batteries. These reasons are believed to be (individually or in combination) the reasons for the following: to date, no dendrite-like features have been observed for any of the large number of rechargeable alkali metal cells we studied.

In a preferred embodiment, the anode active material is a pre-lithiated version of graphene sheets selected from pristine graphene, graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, chemically functionalized graphene, or combinations thereof. The starting graphite material used to produce any of the above graphene materials may be selected from natural graphite, artificial graphite, mesophase carbon, mesophase pitch, mesophase carbon microbeads, soft carbon, hard carbon, coke, carbon fibers, carbon nanofibers, carbon nanotubes, or combinations thereof. Graphene materials are also good conductive additives for anode and cathode active materials for lithium batteries.

The constituent graphene planes of graphite crystallites in natural or artificial graphite particles can be expanded and extracted or isolated to obtain single graphene sheets of hexagonal carbon atoms that are monoatomic in thickness, provided that the interplanar van der waals forces can be overcome. An isolated single graphene plane of carbon atoms is commonly referred to as single layer graphene. A stack of a plurality of graphene planes bonded by van der waals force in the thickness direction with a spacing between the graphene planes of about 0.3354nm is generally referred to as multi-layered graphene. The multi-layered graphene platelets have up to 300 graphene planes (< 100nm in thickness), but more typically up to 30 graphene planes (< 10nm in thickness), even more typically up to 20 graphene planes (< 7nm in thickness), and most typically up to 10 graphene planes (commonly referred to as few-layer graphene in the scientific community). Single-layer graphene sheets and multi-layer graphene sheets are collectively referred to as "nano-graphene platelets" (NGPs). Graphene sheets/platelets (collectively referred to as NGPs) are a new class of carbon nanomaterials (2-D nanocarbons) that differ from 0-D fullerenes, 1-DCNT or CNF and 3-D graphite. For the purposes of defining the claims and as generally understood in the art, graphene materials (isolated graphene sheets) are not (and do not include) Carbon Nanotubes (CNTs) or Carbon Nanofibers (CNFs).

In one approach, graphene materials are obtained by intercalating natural graphite particles with strong acids and/or oxidizing agents to obtain Graphite Intercalation Compounds (GICs) or Graphite Oxides (GO), as shown in fig. 5. The presence of chemical species or functional groups in the interstitial spaces between graphene planes in a GIC or GO serves to increase the inter-graphene spacing (d)₀₀₂As determined by X-ray diffraction) to thereby significantly reduce van der waals forces that would otherwise hold graphene planes together along the c-axis direction. GIC or GO is most often produced by immersing natural graphite powder in a mixture of sulfuric acid, nitric acid (the oxidant) and another oxidant (e.g. potassium permanganate or sodium perchlorate). If an oxidizing agent is present during the intercalation procedure, the resulting GIC is actually some type of Graphite Oxide (GO) particles. The GIC or GO is then repeatedly washed and rinsed in water to remove excess acid, producing a graphite oxide suspension or dispersion containing discrete and visually identifiable graphite oxide particles dispersed in water. To produce graphene materials, one of two processing routes can be followed after this washing step, briefly described as follows:

route 1 involves the removal of water from the suspension to obtain "expandable graphite", which is essentially a mass of dry GIC or dry graphite oxide particles. Upon exposure of the expandable graphite to temperatures in the range of from typically 800 c to 1,050 c for about 30 seconds to 2 minutes, the GIC undergoes 30-300 times rapid volume expansion to form "graphite worms," each of which is an assemblage of expanded, yet interconnected, largely unseparated graphite flakes.

In route 1A, these graphite worms (expanded graphite or "network of interconnected/unseparated graphite flakes") can be recompressed to obtain flexible graphite sheets or foils, typically having a thickness in the range from 0.1mm (100 μm) to 0.5mm (500 μm). Alternatively, the use of low intensity air mills or shears may be selected to simply decompose the graphite worms for the purpose of producing so-called "expanded graphite flakes," which contain predominantly graphite flakes or platelets thicker than 100nm (and thus by definition not nanomaterials).

In route 1B, expanded graphite is subjected to high intensity mechanical shearing (e.g., using an ultrasonic generator, a high shear mixer, a high intensity air jet mill, or a high energy ball mill) to form separate single and multi-layered graphene sheets (collectively referred to as NGPs), as disclosed in our U.S. application No. 10/858,814(06/03/2004) (U.S. patent publication No. 2005/0271574). Single-layer graphene can be as thin as 0.34nm, while multi-layer graphene can have a thickness of up to 100nm, but more typically less than 10nm (commonly referred to as few-layer graphene). A plurality of graphene sheets or platelets may be made into a sheet of NGP paper using a papermaking process. The NGP paper sheet is an example of a porous graphene structure layer used in the method of the present invention.

Route 2 entails subjecting a graphite oxide suspension (e.g., graphite oxide particles dispersed in water) to ultrasonic treatment for the purpose of separating/isolating individual graphene oxide sheets from the graphite oxide particles. This is based on the following point: the spacing between graphene planes has increased from 0.3354nm in natural graphite to 0.6-1.1nm in highly oxidized graphite oxide, significantly reducing van der waals forces holding adjacent planes together. The ultrasonic power may be sufficient to further separate the graphene planar sheets to form fully separated, isolated or discrete Graphene Oxide (GO) sheets. These graphene oxide sheets may then be chemically or thermally reduced to obtain "reduced graphene oxide" (RGO), typically having an oxygen content of 0.001-10% by weight, more typically 0.01-5% by weight, most typically and preferably less than 2% by weight oxygen.

For the purposes of defining the claims of the present application, NGP or graphene materials include single and multiple layers (typically less than 10 layers) of discrete sheets/platelets of pristine graphene, graphene oxide, Reduced Graphene Oxide (RGO), graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, chemically functionalized graphene, doped graphene (e.g. doped with B or N). Pristine graphene has substantially 0% oxygen. RGO typically has an oxygen content of 0.001% -5% by weight. Graphene oxide (including RGO) may have 0.001% -50% oxygen by weight. All graphene materials, except pristine graphene, have 0.001% -50% by weight of non-carbon elements (e.g., O, H, N, B, F, Cl, Br, I, etc.). These materials are referred to herein as non-native graphene materials.

Pristine graphene, in the form of smaller discrete graphene sheets (typically 0.3 to 10 μm), can be produced by direct sonication (also known as liquid phase expansion or production) or supercritical fluid expansion of graphite particles. These methods are well known in the art.

Graphene Oxide (GO) may be obtained by immersing a powder or filament of a starting graphite material (e.g. natural graphite powder) in an oxidizing liquid medium (e.g. a mixture of sulfuric acid, nitric acid and potassium permanganate) in a reaction vessel at a desired temperature for a period of time (typically from 0.5 to 96 hours, depending on the nature of the starting material and the type of oxidant used). As previously described above, the resulting graphite oxide particles may then be subjected to thermal or ultrasound induced expansion to produce isolated GO sheets. And then by using other chemical groups (e.g. -Br, NH)₂Etc.) substitution of-OH groups converts these GO sheets into various graphene materials.

Fluorinated graphene or graphene fluoride is used herein as an example of a halogenated graphene material group. There are two different approaches that have been followed to produce fluorinated graphene: (1) fluorination of pre-synthesized graphene: the process requires the use of a fluorinating agent such as XeF₂Or F-based plasma treating graphene prepared by mechanical puffing or by CVD growth; (2) puffing the multilayer graphite fluoride: both mechanical and liquid phase expansion of graphite fluoride can be readily achieved.

F₂Interaction with graphite at high temperatures results in covalent graphite fluoride (CF)_nOr (C)₂F)_nWhile forming Graphite Intercalation Compound (GIC) C at low temperature_xF (x is more than or equal to 2 and less than or equal to 24). In (CF)_nThe carbon atom being sp3 hybridizedAnd thus the fluorocarbon layer is corrugated, consisting of trans-linked cyclohexane chairs. In (C)₂F)_nOnly half of the C atoms are fluorinated and each pair of adjacent carbon sheets are linked together by a covalent C — C bond. Systematic studies of the fluorination reaction show that the resulting F/C ratio depends to a large extent on the fluorination temperature, the partial pressure of fluorine in the fluorination gas, and the physical properties of the graphite precursor, including graphitization degree, particle size, and specific surface area. In addition to fluorine (F)₂) In addition, other fluorinating agents may be used, although most of the prior art references refer to the use of F₂The gas is fluorinated (sometimes in the presence of fluoride).

In order to expand the layered precursor material into the state of a single layer or several layers, the attractive forces between adjacent layers must be overcome and the layers further stabilized. This can be achieved by covalent modification of the graphene surface with functional groups or by non-covalent modification using specific solvents, surfactants, polymers, or donor-acceptor aromatic molecules. The liquid phase expansion process involves ultrasonication of graphite fluoride in a liquid medium.

Nitridation of graphene can be performed by exposing a graphene material (e.g., graphene oxide) to ammonia at high temperatures (200-400 ℃). The graphene nitride can be formed at a lower temperature by a hydrothermal method; for example by sealing GO and ammonia in an autoclave and then warming to 150-250 ℃. Other methods of synthesizing nitrogen-doped graphene include nitrogen plasma treatment on graphene, arc discharge between graphite electrodes in the presence of ammonia, ammonolysis of graphene oxide under CVD conditions, and hydrothermal treatment of graphene oxide and urea at different temperatures.

There is no limitation on the type of anode active material or cathode active material that can be used to practice the present invention. Preferably, in the lithium battery cell of the present invention, the anode active material exceeds Li/Li when the battery is charged⁺(i.e. with respect to Li → Li as the standard potential)⁺+e^-) Lithium ions are absorbed at an electrochemical potential of less than 1.0 volt, preferably less than 0.7 volt. In a preferred embodiment, the anode active material of the lithium battery is selected from the group consisting of: (a) particles of lithium metal or lithium metal alloy; (b) natural graphite particles, artificial graphite particles, mesocarbon microbeads (MCMB), carbon particles (including soft and hard carbon), needle coke, carbon nanotubes, carbon nanofibers, carbon fibers, and graphite fibers; (c) silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), nickel (Ni), cobalt (Co), manganese (Mn), titanium (Ti), iron (Fe), and cadmium (Cd); (d) alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al or Cd with other elements, wherein the alloys or compounds are stoichiometric or non-stoichiometric; (e) oxides, carbides, nitrides, sulfides, phosphides, selenides, and tellurides of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, Ni, Co, Ti, Mn, or Cd, and mixtures or composites thereof; (f) a prelithiated version thereof; (g) pre-lithiated graphene sheets; and combinations thereof.

In certain embodiments, the alkali metal cell is a sodium metal cell or a sodium ion cell and the active material is an anode active material comprising a sodium intercalation compound selected from: petroleum coke, carbon black, amorphous carbon, activated carbon, hard carbon (hard-to-graphitize carbon), soft carbon (easily-graphitize carbon), template carbon, hollow carbon nanowire, hollow carbon sphere, titanate, NaTi₂(PO₄)₃、Na₂Ti₃O₇、Na₂C₈H₄O₄、Na₂TP、Na_xTiO₂(x ═ 0.2 to 1.0), Na₂C₈H₄O₄Materials based on carboxylic acid salts, C₈H₄Na₂O₄、C₈H₆O₄、C₈H₅NaO₄、C₈Na₂F₄O₄、C₁₀H₂Na₄O₈、C₁₄H₄O₆、C₁₄H₄Na₄O₈Or a combination thereof.

In certain embodiments, the alkali metal cell is a sodium metal cell or a sodium ion cell and the active material is an anode active material selected from the group consisting of: (a) particles of sodium metal or sodium metal alloy; (b) natural graphite particles, artificial graphite particles, mesocarbon microbeads (MCMB), carbon particles, needle coke, carbon nanotubes, carbon nanofibers, carbon fibers, and graphite fibers; (c) sodium-doped silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), titanium (Ti), cobalt (Co), nickel (Ni), manganese (Mn), cadmium (Cd), and mixtures thereof; (d) sodium-containing alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Co, Ni, Mn, Cd, and mixtures thereof; (e) sodium-containing oxides, carbides, nitrides, sulfides, phosphides, selenides, tellurides, or antimonides of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, Ti, Co, Ni, Mn, Cd, and mixtures or composites thereof; (f) a sodium salt; and (g) graphene sheets pre-loaded with sodium ions; and combinations thereof.

A wide variety of cathode active materials can be used to practice the lithium cell of the present invention. The cathode active material is typically a lithium intercalation compound or a lithium-absorbing compound that is capable of storing lithium ions when the lithium battery is discharged and releasing lithium ions into the electrolyte when recharged. The cathode active material may be selected from inorganic materials, organic or polymeric materials, metal oxide/phosphate/sulfide (the most desirable type of inorganic cathode material), or combinations thereof.

The group of metal oxides, metal phosphates, and metal sulfides consists of lithium cobalt oxides, lithium nickel oxides, lithium manganese oxides, lithium vanadium oxides, lithium transition metal oxides, lithium mixed metal oxides, lithium iron phosphate, lithium manganese phosphate, lithium vanadium phosphate, lithium mixed metal phosphates, transition metal sulfides, and combinations thereof. Specifically, the lithium vanadium oxide may be selected from the group consisting of: VO (vacuum vapor volume)₂、Li_xVO₂、V₂O₅、Li_xV₂O₅、V₃O₈、Li_xV₃O₈、Li_xV₃O₇、V₄O₉、Li_xV₄O₉、V₆O₁₃、Li_xV₆O₁₃Doping thereofThe formula (I), derivatives thereof, and combinations thereof, wherein 0.1<x<5. The lithium transition metal oxide may be selected from the layered compound LiMO₂Spinel type compound LiM₂O₄Olivine-type compound LiMPO₄Silicate compound Li₂MSiO₄Lithium iron phosphate Hydroxyphosphorus Compound LiMPO₄F. Borate compound LiMBO₃Or combinations thereof, wherein M is a transition metal or a mixture of transition metals.

Other inorganic materials used as cathode active materials may be selected from sulfur, sulfur compounds, lithium polysulfides, transition metal dichalcogenides, transition metal trichalcogenides, or combinations thereof. In particular, the inorganic material is selected from TiS₂、TaS₂、MoS₂、NbSe₃、MnO₂、CoO₂Iron oxide, vanadium oxide, or a combination thereof. These will be discussed further later.

In particular, the inorganic material may be selected from: (a) bismuth selenide or bismuth telluride, (b) a di-or tri-chalcogenide of a transition metal, (c) a sulfide, selenide, or telluride of niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, cobalt, manganese, iron, nickel, or a transition metal; (d) boron nitride, or (e) a combination thereof.

The organic or polymeric material may be selected from poly (anthraquinone sulfides) (PAQS), lithium oxycarbide, 3,4,9, 10-perylenetetracarboxylic dianhydride (PTCDA), poly (anthraquinone sulfides), pyrene-4, 5,9, 10-tetraone (PYT), polymer-bonded PYT, quinones (triazenes), redox active organic materials, Tetracyanoquinodimethane (TCNQ), Tetracyanoethylene (TCNE), 2,3,6,7,10, 11-Hexamethoxytriphenylene (HMTP), poly (5-amino-1, 4-dihydroxyanthraquinone) (PADAQ), phosphazene disulfide polymers ([ (NPS s)₂)₃]n), lithiated 1,4,5, 8-naphthalenetetraol formaldehyde polymers, Hexaazatrinaphthalene (HATN), hexaazatrinexanenitrile (HAT (CN)₆) 5-benzylidenehydantoin, isatin lithium salt, pyromellitic diimide lithium salt, tetrahydroxy-p-benzoquinone derivative (THQLi)₄) N, N ' -diphenyl-2, 3,5, 6-tetraone piperazine (PHP), N ' -diallyl-2, 3,5, 6-tetraone piperazine (AP), N ' -dipropyl-2, 3,5, 6-tetraone piperazine (PRP), thioether poly (ether-co-ether-co-A compound, a quinone compound, 1, 4-benzoquinone, 5,7,12, 14-Pentacontanone (PT), 5-amino-2, 3-dihydro-1, 4-dihydroxyanthraquinone (ADDAQ), 5-amino-1, 4-dihydroxyanthraquinone (ADAQ), quinoid calixarene, Li₄C₆O₆、Li₂C₆O₆、Li₆C₆O₆Or a combination thereof.

The thioether polymer is selected from poly [ methanetrinitrobenzylnitroamine-tetrakis (thiomethylene) ] (PMTTM), poly (2, 4-dithiopentene) (PDTP), a polymer containing poly (ethylene-1, 1,2, 2-tetrathiol) (PETT) as a main chain thioether polymer, a side chain thioether polymer having a main chain composed of conjugated aromatic moieties and having thioether side chains as side chains, poly (2-phenyl-1, 3-dithiolane) (PPDT), poly (1, 4-bis (1, 3-dithiolane-2-yl) benzene) (PDDTB), poly (tetrahydrobenzodithiophene) (PTHBDT), poly [1,2,4, 5-tetrakis (propylthio) benzene ] (PTKPTB), or poly [3,4 (ethylenedithio) thiophene ] (PEDTT).

The organic material may be selected from phthalocyanine compounds selected from copper phthalocyanine, zinc phthalocyanine, tin phthalocyanine, iron phthalocyanine, lead phthalocyanine, nickel phthalocyanine, vanadyl phthalocyanine, chromium phthalocyanine, magnesium phthalocyanine, manganese phthalocyanine, dilithium phthalocyanine, aluminum phthalocyanine chloride, cadmium phthalocyanine, chlorogallium phthalocyanine, cobalt phthalocyanine, silver phthalocyanine, metal-free phthalocyanines, chemical derivatives thereof, or combinations thereof.

The lithium intercalation compound or lithium absorbing compound may be selected from a metal carbide, a metal nitride, a metal boride, a metal dichalcogenide, or a combination thereof. Preferably, the lithium intercalation compound or lithium-absorbing compound is selected from an oxide, dichalcogenide, trichalcogenide, sulfide, selenide, or telluride of niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, vanadium, chromium, cobalt, manganese, iron, or nickel in the form of a nanowire, nanodisk, nanoribbon, or nanoplatelet.

We have found that in the lithium battery of the present invention prepared by the direct active material-electrolyte injection method of the present invention, a wide variety of two-dimensional (2D) inorganic materials can be used as a cathode active material. Layered materials are representative of materials that can exhibit unexpected electronic properties and good affinity for lithium ionsAnd diverse sources of 2D systems of force. Although graphite is the best known layered material, Transition Metal Dichalcogenides (TMD), Transition Metal Oxides (TMO) and various other compounds such as BN, Bi₂Te₃And Bi₂Se₃Are also potential sources of 2D materials.

Preferably, the lithium intercalation compound or lithium-absorbing compound is selected from nanodiscs, nanoplatelets, nanocoatings, or nanoplatelets of an inorganic material selected from: (a) bismuth selenide or bismuth telluride, (b) a di-or tri-chalcogenide of a transition metal, (c) a sulfide, selenide, or telluride of niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, cobalt, manganese, iron, nickel, or a transition metal; (d) boron nitride, or (e) a combination thereof; wherein the disc, platelet or sheet has a thickness of less than 100 nm. The lithium intercalation compound or lithium-absorbing compound may contain nanodiscs, nanoplatelets, nanocoatings, or nanoplatelets of a compound selected from the group consisting of: (i) bismuth selenide or bismuth telluride, (ii) transition metal dichalcogenides or trisulfides, (iii) sulfides, selenides, or tellurides of niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, cobalt, manganese, iron, nickel, or transition metals; (iv) (iv) boron nitride, or (v) a combination thereof, wherein the disk, platelet, coating or sheet has a thickness of less than 100 nm.

In a rechargeable sodium cell, the cathode active material may contain a sodium intercalation compound selected from: NaFePO₄Sodium iron phosphate, Na_0.7FePO₄、Na_1.5VOPO₄F_0.5、Na₃V₂(PO₄)₃、Na₃V2(PO₄)₂F₃、Na₂FePO₄F、NaFeF₃、NaVPO₄F、Na₃V₂(PO₄)₂F₃、Na_1.5VOPO₄F_0.5、Na₃V₂(PO₄)₃、NaV₆O₁₅、Na_xVO₂、Na_0.33V₂O₅、Na_xCoO₂Sodium cobalt oxide and Na_2/3[Ni_1/3Mn_2/3]O₂、Na_x(Fe_1/2Mn_1/2)O₂、Na_xMnO₂(sodium manganese bronze), Na_0.44MnO₂、Na_0.44MnO₂/C、Na₄Mn₉O₁₈、NaFe₂Mn(PO₄)₃、Na₂Ti₃O₇、Ni_1/3Mn_1/3Co_1/3O₂、Cu_0.56Ni_0.44HCF (copper and nickel hexacyanoferrate), NiHCF (nickel hexacyanoferrate), Na_xCoO₂、NaCrO₂、Na₃Ti₂(PO₄)₃、NiCo₂O₄、Ni₃S₂/FeS₂、Sb₂O₄、Na₄Fe(CN)₆/C、NaV_1-xCr_xPO₄F、Se_yS_z(selenium and selenium/sulfur, z/y from 0.01 to 100), Se (without S), phosphomanganite, or combinations thereof.

Alternatively, the cathode active material may be selected from functional materials or nanostructured materials having an alkali metal ion capturing functional group or an alkali metal ion storage surface in direct contact with the electrolyte. Preferably, the functional group reacts reversibly with an alkali metal ion, forms a redox pair with an alkali metal ion, or forms a chemical complex with an alkali metal ion. The functional or nanostructured material may be selected from the group consisting of: (a) nanostructured or porous disordered carbon material selected from soft carbon, hard carbon, polymeric or carbonized resins, mesophase carbon, coke, carbonized pitch, carbon black, activated carbon, nano-cellular carbon foam or partially graphitized carbon; (b) nano-graphene platelets selected from single-layer graphene sheets or multi-layer graphene platelets; (c) carbon nanotubes selected from single-walled carbon nanotubes or multi-walled carbon nanotubes; (d) carbon nanofibers, nanowires, metal oxide nanowires or fibers, conductive polymer nanofibers, or a combination thereof; (e) a carbonyl-containing organic or polymeric molecule; (f) functional materials containing carbonyl, carboxyl or amino groups; and combinations thereof.

The functional or nanostructured material may be selected from the group consisting of: poly (2, 5-dihydroxy)-1, 4-benzoquinone-3, 6-methylene), Na_xC₆O₆(x＝1-3)、Na₂(C₆H₂O₄)、Na₂C₈H₄O₄Sodium terephthalate, Na₂C₆H₄O₄(sodium trans-muconate), 3,4,9, 10-perylenetetracarboxylic-dianhydride (PTCDA) sulfide polymer, PTCDA, 1,4,5, 8-naphthalenetetracarboxylic-dianhydride (NTCDA), benzene-1, 2,4, 5-tetracarboxylic-dianhydride, 1,4,5, 8-tetrahydroxyanthraquinone, tetrahydroxy-p-benzoquinone, and combinations thereof. Desirably, the functional or nanostructured material has a structure selected from-COOH, ═ O, -NH₂-OR OR-COOR, wherein R is a hydrocarbyl group.

Non-graphene 2D nanomaterials (single or few layers (up to 20 layers)) can be produced by several methods: mechanical cleaving, laser ablation (e.g., ablation of TMD into a single layer using laser pulses), liquid phase expansion, and synthesis by thin film techniques such as PVD (e.g., sputtering), evaporation, vapor phase epitaxy, liquid phase epitaxy, chemical vapor phase epitaxy, Molecular Beam Epitaxy (MBE), Atomic Layer Epitaxy (ALE), and plasma assisted versions thereof.

A wide range of electrolytes can be used in the practice of the present invention. Most preferred are non-aqueous organic and/or ionic liquid electrolytes. The nonaqueous electrolyte to be used herein may be produced by dissolving an electrolyte salt in a nonaqueous solvent. Any known non-aqueous solvent that has been used as a solvent for a lithium secondary battery may be used. It may be preferable to use a nonaqueous solvent mainly composed of a mixed solvent containing Ethylene Carbonate (EC) and at least one kind of a nonaqueous solvent (hereinafter referred to as a second solvent) having a melting point lower than the above-mentioned ethylene carbonate and having a donor number of 18 or less. This non-aqueous solvent is advantageous because it: (a) is stable to negative electrodes containing carbonaceous materials that develop well in graphite structures; (b) effectively inhibit the reduction or oxidation decomposition of the electrolyte; and (c) high conductivity. A non-aqueous electrolyte consisting of only Ethylene Carbonate (EC) is advantageous because it is relatively stable to decomposition by reduction of the graphitized carbonaceous material. However, the melting point of EC is relatively high, 39 ℃ to 40 ℃, and its viscosity is relatively high, so that its electrical conductivity is low, thus making EC alone unsuitable for use as a secondary battery electrolyte operating at room temperature or lower. The second solvent to be used with the EC in the mixture functions to lower the viscosity of the solvent mixture than the viscosity of the EC alone, thereby promoting the ionic conductivity of the mixed solvent. Further, when the second solvent having the donor number of 18 or less (the donor number of ethylene carbonate is 16.4) is used, the above-described ethylene carbonate can be easily and selectively solvated with lithium ions, so that the reduction reaction of the second solvent with the carbon-containing material which is supposed to well progress in graphitization is suppressed. In addition, when the donor number of the second solvent is controlled to not more than 18, the oxidative decomposition potential of the lithium electrode can be easily increased to 4V or more, so that a high-voltage lithium secondary battery can be manufactured.

Preferred second solvents are dimethyl carbonate (DMC), ethyl methyl carbonate (MEC), diethyl carbonate (DEC), ethyl propionate, methyl propionate, Propylene Carbonate (PC), gamma-butyrolactone (gamma-BL), Acetonitrile (AN), Ethyl Acetate (EA), Propyl Formate (PF), Methyl Formate (MF), toluene, xylene and Methyl Acetate (MA). These second solvents may be used alone or in a combination of two or more. More desirably, the second solvent should be selected from those having a donor number of 16.5 or less. The viscosity of the second solvent should preferably be 28cps or less at 25 ℃.

The mixing ratio of the above ethylene carbonate in the mixed solvent should preferably be 10% to 80% by volume. If the mixing ratio of ethylene carbonate falls outside this range, the conductivity of the solvent may decrease or the solvent tends to decompose more easily, thereby deteriorating the charge/discharge efficiency. More preferably, the mixing ratio of ethylene carbonate is 20% to 75% by volume. When the mixing ratio of ethylene carbonate in the nonaqueous solvent is increased to 20% by volume or more, the solvating effect of ethylene carbonate on lithium ions is promoted and the solvolysis suppressing effect thereof can be improved.

Examples of preferred mixed solvents are those comprising EC and MEC; comprises EC, PC and MEC; comprises EC, MEC and DEC; comprises EC, MEC and DMC; and comprises EC, MEC, PC and DA composition of EC; wherein the volume ratio of the MEC is controlled to be in the range of from 30% to 80%. By selecting a volume ratio of MEC in the range from 30% to 80%, more preferably 40% to 70%, the conductivity of the solvent can be improved. For the purpose of suppressing the decomposition reaction of the solvent, an electrolyte having carbon dioxide dissolved therein may be used, thereby effectively improving both the capacity and cycle life of the battery. The electrolyte salt to be incorporated into the non-aqueous electrolyte may be selected from lithium salts such as lithium perchlorate (LiClO)₄) Lithium hexafluorophosphate (LiPF)₆) Lithium fluoroborate (LiBF)₄) Lithium hexafluoroarsenate (LiAsF)₆) Lithium trifluoromethanesulfonate (LiCF)₃SO₃) And lithium bistrifluoromethylsulfonyl imide [ LiN (CF)₃SO₂)₂]. Wherein, LiPF₆、LiBF₄And LiN (CF)₃SO₂)₂Is preferred. The content of the above electrolyte salt in the non-aqueous solvent is preferably 0.5 to 2.0 mol/l.

For sodium cells, the electrolyte (including the nonflammable quasi-solid electrolyte) may contain a sodium salt preferably selected from: sodium perchlorate (NaClO)₄) Sodium hexafluorophosphate (NaPF)₆) Sodium fluoroborate (NaBF)₄) Sodium hexafluoroarsenate, sodium trifluoro-methanesulfonate (NaCF)₃SO₃) Bis-trifluoromethylsulfonyl imide sodium salt (NaN (CF)₃SO₂)₂) An ionic liquid salt, or a combination thereof.

Ionic liquids are composed of ions only. Ionic liquids are low melting point salts that are molten or liquid when above a desired temperature. For example, a salt is considered an ionic liquid if it has a melting point below 100 ℃. If the melting temperature is equal to or lower than room temperature (25 ℃), the salt is referred to as a Room Temperature Ionic Liquid (RTIL). Due to the combination of large cations and charge delocalized anions, IL salts are characterized by weak interactions. This results in a low tendency to crystallize due to flexibility (anionic) and asymmetry (cationic).

Typical and well-known ionic liquids are formed by the combination of a 1-ethyl-3-methylimidazolium (EMI) cation and an N, N-bis (trifluoromethane) sulfonamide (TFSI) anion. This combination results in a fluid having an ionic conductivity comparable to many organic electrolyte solutions and a low decomposition tendency and low vapor pressure of up to about 300-400 ℃. This means an electrolyte that is generally low in volatility and non-flammability, and is therefore much safer for batteries.

Ionic liquids are essentially composed of organic ions and, due to the ease of preparation of their various components, have an essentially unlimited number of structural changes. Thus, various salts can be used to design ionic liquids with desired properties for a given application. These include inter alia imidazolium, pyrrolidinium and quaternary ammonium salts as cations and bis (trifluoromethanesulfonyl) imide, bis (fluorosulfonyl) imide and hexafluorophosphate as anions. Ionic liquids have different classes based on their composition, these classes essentially comprising aprotic, protic and zwitterionic types, each suitable for a particular application.

Common cations for Room Temperature Ionic Liquids (RTILs) include, but are not limited to, tetraalkylammonium, di-, tri-, and tetra-alkylimidazolium, alkylpyridinium, dialkyl-pyrrolidinium, dialkyl piperidinium, tetraalkylphosphonium, and trialkyl sulfonium. Common anions for RTILs include, but are not limited to, BF₄ ^-、B(CN)₄ ^-、CH₃BF₃ ^-、CH2CHBF₃ ^-、CF₃BF₃ ^-、C₂F₅BF₃ ^-、n-C₃F₇BF₃ ^-、n-C₄F₉BF₃ ^-、PF₆ ^-、CF₃CO₂ ^-、CF₃SO₃ ^-、N(SO₂CF₃)₂ ^-、N(COCF₃)(SO₂CF₃)^-、N(SO₂F)₂ ^-、N(CN)₂ ^-、C(CN)₃ ^-、SCN^-、SeCN^-、CuCl₂ ^-、AlCl₄ ^-、F(HF)_2.3 ^-And the like. In contrast, imidazolium-or sulfonium-based cations with, for example, AlCl₄ ^-、BF₄ ^-、CF₃CO₂ ^-、CF₃SO₃ ^-、NTf₂ ^-、N(SO₂F)₂ ^-Or F (HF)_2.3 ^-The combination of isocomplex halide anions results in an RTIL with good working conductivity.

RTILs can have typical characteristics such as high intrinsic ionic conductivity, high thermal stability, low volatility, low (almost zero) vapor pressure, non-flammability, ability to remain as a liquid over a wide range of temperatures above and below room temperature, high polarity, high viscosity, and a wide electrochemical window. These properties are desirable attributes in addition to high viscosity when it comes to using RTILs as electrolyte components (salts and/or solvents) in supercapacitors.

In the following, we provide some examples of several different types of anode active materials, cathode active materials, and porous current collector materials (e.g., graphite foam, graphene foam, and metal foam) to illustrate the best mode of practicing the invention. These illustrative examples, as well as other portions of the specification and drawings, individually or in combination, are sufficient to enable one of ordinary skill in the art to practice the invention. However, these examples should not be construed as limiting the scope of the invention.

Example 1: preparation of Graphene Oxide (GO) and Reduced Graphene Oxide (RGO) nanoplates from natural graphite powder

Natural Graphite from Huadong Graphite Co (Huadong Graphite Co.) (celand china) was used as the starting material. GO is obtained by following the well-known modified helmholtz method, which involves two oxidation stages. In a typical procedure, the first oxidation is effected under the following conditions: 1100mg of graphite was placed in a 1000mL long-necked flask. Then, 20g of K was added to the flask₂S₂O₈20g of P₂O₅And 400mL of concentrated H₂SO₄Aqueous solution (96%). The mixture was heated at reflux for 6 hours and then left undisturbed at room temperature for 20 hours. The graphite oxide was filtered and rinsed with copious amounts of distilled water until neutral pH. At the position ofThe wet cake material is recovered at the end of the first oxidation.

For the second oxidation process, the previously collected wet cake was placed in a container containing 69mL of concentrated H₂SO₄Aqueous solution (96%) in a long-necked flask. The flask was kept in an ice bath while slowly adding 9g KMnO₄. Care is taken to avoid overheating. The resulting mixture was stirred at 35 ℃ for 2 hours (the color of the sample turned dark green) and then 140mL of water was added. After 15min, the reaction mixture was purified by adding 420mL of water and 15mL of 30 wt.% H₂O₂To stop the reaction. At this stage the color of the sample turned bright yellow. To remove the metal ions, the mixture was filtered and washed with 1:10 aqueous HCl. The collected material was gently centrifuged at 2700g and rinsed with deionized water. The final product was a wet cake containing 1.4 wt.% GO (as estimated from dry extract). Subsequently, a liquid dispersion of GO platelets was obtained by mild sonication of the wet-cake material diluted in deionized water.

Surfactant stabilized RGO (RGO-BS) is obtained by diluting the wet cake in an aqueous solution of a surfactant rather than pure water. A mixture of commercially available sodium cholate (50 wt.%) and sodium deoxycholate (50 wt.%) salts supplied by Sigma Aldrich (Sigma Aldrich) was used. The surfactant weight fraction was 0.5 wt.%. The fraction remained constant for all samples. Sonication was performed using a Benedict Soifier S-250A equipped with a 13mm step disruptor horn and a 3mm conical microtip operating at a frequency of 20 kHz. For example, 10mL of an aqueous solution containing 0.1 wt.% GO was sonicated for 10min and then centrifuged at 2700g for 30min to remove any undissolved large particles, aggregates and impurities. The chemical reduction to obtain as-received GO to produce RGO was performed by following the following procedure, which involved placing 10mL of a 0.1 wt.% GO aqueous solution in a 50mL long-necked flask. Then, 10 μ L of 35 wt.% N₂H₄(hydrazine) aqueous solution and 70mL of 28 wt.% NH₄An aqueous OH (ammonia) solution is added to the mixture and stabilized by a surfactant. The solution was heated to 90 ℃ and refluxed for 1 h. The pH value measured after the reaction was about 9. The color of the sample turned dark black during the reduction reaction.

In certain lithium batteries of the invention, RGO is used as a conductive additive in either or both of the anode and cathode active materials. In selected lithium ion cells, pre-lithiated RGO (e.g., RGO + lithium particles or RGO pre-deposited with a lithium coating) is also used as the anode active material.

For comparison purposes, a slurry coating and drying procedure was performed to produce a conventional electrode. An anode and a cathode, and a separator disposed between the two electrodes, were then assembled and encapsulated in an Al plastic laminate encapsulation envelope, and then injected with liquid electrolyte to form a prior art lithium battery cell.

Example 2: preparation of pristine graphene sheets (0% oxygen)

Recognizing the possibility that the high defect number in GO sheets acts to reduce the electrical conductivity of individual graphene planes, we decided to investigate whether the use of pristine graphene sheets (non-oxidized and oxygen-free, non-halogenated and halogen-free, etc.) could produce an electrically conductive additive with high electrical and thermal conductivity. Prelithiated pristine graphene is also used as the anode active material. Pristine graphene sheets are produced using direct sonication or a liquid phase production process.

In a typical procedure, 5 grams of graphite flakes ground to a size of about 20 μm or less are dispersed in 1,000mL of deionized water (containing 0.1% by weight of a dispersant, available from DuPont)

FSO) to obtain a suspension. An ultrasonic energy level of 85W (Branson S450 ultrasonicator) was used for puffing, separation and size reduction of graphene sheets for a period of 15 minutes to 2 hours. The resulting graphene sheets are pristine graphene that has never been oxidized and is oxygen-free and relatively defect-free. The pristine graphene is substantially free of any non-carbon elements.

Pristine graphene sheets are then incorporated into the cell as a conductive additive along with the anode active material (or cathode active material in the cathode) using both the inventive procedure of injecting the slurry into the foam cells and conventional slurry coating, drying, and lamination procedures. Both lithium ion batteries and lithium metal batteries (only implanted into the cathode) were investigated.

Example 3: preparation of prelithiated graphene fluoride sheets as anode active materials for lithium ion batteries

We have used several methods to produce GF, but only one method is described herein as an example. In a typical procedure, Highly Expanded Graphite (HEG) is prepared from an intercalation compound₂F·xClF₃And (4) preparation. HEG was further fluorinated with chlorine trifluoride vapor to produce Fluorinated Highly Expanded Graphite (FHEG). The pre-cooled Teflon (Teflon) reactor is filled with 20-30mL of liquid pre-cooled ClF₃The reactor was closed and cooled to liquid nitrogen temperature. Then, no more than 1g of HEG was placed in a container with a container for ClF₃The gas enters the reactor and is located in an aperture within the reactor. Form a product with approximate formula C in 7-10 days₂F as a grey beige product.

Subsequently, a small amount of FHEG (approximately 0.5mg) was mixed with 20-30mL of organic solvent (methanol and ethanol respectively) and subjected to sonication (280W) for 30min, resulting in the formation of a homogeneous yellowish dispersion. After removal of the solvent, the dispersion turned brown powder. Graphene fluoride powder is mixed with surface stabilized lithium powder in a liquid electrolyte such that prelithiation occurs.

Example 4: some examples of electrolytes used

Preferred sodium metal salts include: sodium perchlorate (NaClO)₄) Sodium hexafluorophosphate (NaPF)₆) Sodium fluoroborate (NaBF)₄) Sodium hexafluoroarsenate, potassium hexafluoroarsenate, sodium trifluoro-methanesulfonate (NaCF)₃SO₃) And sodium bis (trifluoromethylsulfonyl) imide (NaN (CF)₃SO₂)₂). The following is a good choice of lithium salts that tend to dissolve well in selected organic or ionic liquid solvents: lithium fluoroborate (LiBF)₄) Lithium trifluoromethanesulfonate (LiCF)₃SO₃) Lithium bistrifluoromethylsulfonyl imide (LiN (CF)₃SO₂)₂Or LITFSI), lithium bis (oxalato) borate (LiBOB), lithium oxalyldifluoroborate (LiBF)₂C₂O₄) And lithium bis (per fluoro ethyl sulfonyl) imide (LiBETI). A good electrolyte additive to help stabilize Li metal is LiNO₃. Particularly useful ionic liquid-based lithium salts include: lithium bis (trifluoromethanesulfonyl) imide (LiTFSI).

Preferred organic liquid solvents include: ethylene Carbonate (EC), dimethyl carbonate (DMC), ethyl methyl carbonate (MEC), diethyl carbonate (DEC), Propylene Carbonate (PC), Acetonitrile (AN), Vinylene Carbonate (VC), Allyl Ethyl Carbonate (AEC), 1, 3-Dioxolane (DOL), 1, 2-Dimethoxyethane (DME), Tetraglyme (TEGDME), poly (ethylene glycol) dimethyl ether (PEGDME), diethylene glycol dibutyl ether (degbe), 2-ethoxyethyl ether (EEE), hydrofluoroethers (e.g., TPTP), sulfones, and sulfolane.

Preferred ionic liquid solvents may be selected from Room Temperature Ionic Liquids (RTILs) having cations selected from: tetraalkylammonium, dialkylimidazolium, alkylpyridinium, dialkylpyrrolidinium, or dialkylpiperidinium. The counter anion is preferably selected from BF₄ ^-、B(CN)₄ ^-、CF₃CO₂ ^-、CF₃SO₃ ^-、N(SO₂CF₃)₂ ^-、N(COCF₃)(SO₂CF₃)^-Or N (SO)₂F)₂ ^-. Particularly useful ionic liquid-based solvents include N-N-butyl-N-ethylpyrrolidinium bis (trifluoromethanesulfonyl) imide (BEPyTFSI), N-methyl-N-propylpiperidinium bis (trifluoromethanesulfonyl) imide (PP)₁₃TFSI), and N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium bis (trifluoromethylsulfonyl) imide.

Example 5: vapor pressures of some solvents and corresponding quasi-solid electrolytes with various sodium salt molecular ratios.

Several solvents (DOL, DME, PC, AN, with or without ionic liquid-based co-solvent PP) were measured₁₃TFSI) in the addition of a wide range of molecular ratio sodium salts (e.g., sodium fluoroborate (NaBF)₄) Sodium perchlorate (NaClO)₄) Or sodium bis (trifluoromethanesulfonyl) imide (NaTFSI)) before and afterThe vapor pressure. A quantity of vapor pressure ratio data (p)_sWhere/p is vapor pressure of solution/vapor pressure of solvent alone) is plotted as a function of the lithium salt molecular ratio x, as shown in fig. 2(a) to 2(D), and a curve representing raoult's law is plotted. In all cases, only for up to x<0.15, the vapor pressure ratio complies with the theoretical prediction based on raoult's law, above which the vapor pressure deviates from raoult's law in a novel and unprecedented manner. It appears that the vapor pressure decreases at a very high rate when the molecular ratio x exceeds 0.2, and rapidly approaches a minimum or essentially zero when x exceeds 0.4. At very low p_sWith the value of/p, the vapor phase of the electrolyte cannot ignite or once initiated the flame cannot last longer than 3 seconds.

Example 6: the flash point and vapor pressure of some solvents and corresponding quasi-solid electrolytes with a sodium or lithium salt molecular ratio of x ═ 0.3.

The flash point and vapor pressure of several solvents and their electrolytes with Na or Li salt molecular ratio x ═ 0.3 are presented in table 1 below. It may be noted that any liquid having a flash point below 38.7 ℃ is flammable according to OSHA (occupational safety and health administration) classification. However, to ensure safety, we designed quasi-solid electrolytes to exhibit a flash point significantly above 38.7 ℃ (with a large margin, e.g. at least 50 ° increase and preferably above 150 ℃). The data in table 1 show that the addition of alkali metal salt to a molecular ratio of 0.35 is generally sufficient to meet these criteria. All of our quasi-solid electrolytes are nonflammable.

Table 1: the flash point and vapor pressure of the selected solvent and its electrolyte with an alkali metal salt molecular ratio x of 0.3 (flash point data for the first 4 liquids are given as reference points).

^*Any liquid having a flash point below 38.7 ℃ is flammable, according to OSHA (occupational safety and health administration) classification.

^**The standard atmospheric pressure of 1 is 101,325Pa 101.325kPa 1,013.25 hPa. 133.3 Pa-0.1333 kPa

Example 7: number of alkali metal ions transferred in several electrolytes

Several types of electrolytes (e.g., NaTFSI salt/(EMImTFSI + DME) solvent) were investigated for Na relative to the molecular ratio of the lithium salt⁺Ion transfer numbers, and representative results are summarized in fig. 3(a) to 3 (D). Generally, low salt concentration of Na in the electrolyte⁺The ion transfer number decreases with increasing concentration from 0 to 0.2-0.35. However, above the molecular ratio of x-0.2-0.35, the number of transfers increased with increasing salt concentration, indicating Na⁺Fundamental changes in ion transport mechanisms. This is explained in the preceding theoretical subsection. When Na is present⁺Electrolytes with ions at low salt concentrations (e.g. x)<0.2) in the course of travel, Na⁺The ions may drag multiple solvated molecules with them. This cooperative migration of clusters of charged species can be further hindered if the fluid viscosity is increased as more salt is dissolved in the solvent. In contrast, when an ultra-high concentration of sodium salt (having x) is present>0.2) time, Na⁺The number of ions may greatly exceed the available solvating molecules that might otherwise cluster the sodium ions, thereby forming polyionic complex species and slowing their diffusion process. The high Na content⁺The ion concentration makes it possible to have more "free Na⁺Ions "(unclustered), thereby providing higher Na⁺Number of transfer (thus providing easy Na)⁺Transmission). The sodium ion transport mechanism changes from a polyion complex dominated mechanism (with overall larger hydrodynamic radius) to having a large amount of free Na available⁺Single-ion dominated mechanism of ions (with smaller hydrodynamic radius). The observations were further identified as: a sufficient amount of Na⁺The ions canTo move rapidly through or from the quasi-solid electrolyte to make themselves readily available for interaction or reaction with the cathode (during discharge) or anode (during charge), thereby ensuring good rate performance of the sodium secondary cells. Most importantly, these highly concentrated electrolytes are non-flammable and safe. Up to now, it has been difficult to obtain combined safety, easy sodium ion transport, and electrochemical performance characteristics for all types of sodium and lithium secondary batteries.

Example 8: lithium iron phosphate (LFP) cathode for lithium metal batteries

LFP powders (uncoated or carbon coated) are commercially available from several sources. In this example, graphene sheets (RGO) and Carbon Nanofibers (CNF) are separately contained as conductive filaments in an electrode containing LFP particles as a cathode active material and an electrolyte containing a lithium salt dissolved in an organic solvent. The lithium salt used in this example includes lithium fluoroborate (LiBF)₄) And the organic solvent is PC, DOL, DEC, and mixtures thereof. A wide range of conductive filament volume fractions from 0.1% to 30% were included in this study. The formation of the electrode layer is accomplished by using the following sequence of steps:

sequence 1 (S1): firstly, LiBF is firstly₄The salt is dissolved in a mixture of PC and DOL to form electrolytes with salt concentrations of 1.0M, 2.5M, and 3.5M, respectively. (in the case of concentrations of 2.5M or higher, the resulting electrolyte is no longer a liquid electrolyte. it behaves more like a solid in nature, and is therefore the term "quasi-solid") then, RGO or CNT filaments are dispersed in the electrolyte to form a filament-electrolyte suspension. Mechanical shear is used to help form a uniform dispersion. (the filament-electrolyte suspension is quite viscous even at low salt concentrations of 1.0M). The cathode active material LFP particles are then dispersed in the filament-electrolyte suspension to form a quasi-solid electrode material.

Sequence 2 (S2): firstly, LiBF is firstly₄The salt is dissolved in a mixture of PC and DOL to form electrolytes with salt concentrations of 1.0M, 2.5M, and 3.5M, respectively. Then, the cathode active material LFP particles are dispersed in the electrolyte to form active particlesA particle-electrolyte suspension. Mechanical shear is used to help form a uniform dispersion. (the active particle-electrolyte suspension is quite viscous even at low salt concentrations of 1.0M). RGO or CNT filaments are then dispersed in the active particle-electrolyte suspension to form a quasi-solid electrode material.

Sequence 3 (S3): first, a desired amount of RGO or CNT filaments are dispersed in a liquid solvent mixture (PC + DOL) that does not contain a dissolved lithium salt therein. Mechanical shearing is used to help form a uniform suspension of the conductive filaments in the solvent. Then LiBF is added₄Salt and LFP particles are added to the suspension, allowing LiBF₄The salt is dissolved in the solvent mixture of the suspension to form electrolytes having salt concentrations of 1.0M, 2.5M, and 3.5M, respectively. Simultaneously or subsequently, LFP particles are dispersed in an electrolyte to form a deformable quasi-solid electrode material consisting of active material particles and conductive filaments dispersed in a quasi-solid electrolyte (not a liquid electrolyte). In the quasi-solid electrode material, the conductive filaments are percolated to form a 3D network of electron conducting pathways. The 3D conductive network is maintained when the electrode material is formed into an electrode of a battery.

The conductivity of the electrodes was measured using a four-point probe method. The results are summarized in fig. 6(a) and 6 (B). These data indicate that, except for the electrode made by following sequence 3, no percolation of the conductive filaments (CNF or RGO) typical of 3D networks used to form electron conduction paths occurs until the volume fraction of the conductive filaments exceeds 10% -12%. In other words, the step of dispersing the conductive filaments in the liquid solvent must be performed before dissolving the lithium salt or sodium salt in the liquid solvent and before dispersing the active material particles in the solvent. Such a sequence may also bring the percolation threshold as low as 0.5% -2.0%, so that conductive electrodes can be produced by using very small amounts of conductive additives, and thus higher proportions of active material (and higher energy density). To date, these observations have been found to be consistent with all types of electrodes containing active material particles, conductive filaments, and electrolyte. This is a crucial and unexpected process requirement for the preparation of high performance alkali metal batteries with both high energy density and high power density.

The quasi-solid cathode, porous separator and quasi-solid anode (prepared in a similar manner but with artificial graphite particles as the anode active material) were then assembled together to form a unit cell, which was then enclosed in a protective casing (laminated aluminum plastic bag) having two terminals protruding outward to produce a battery. Cells containing liquid electrolyte (1M) and quasi-solid electrolyte (2.5M and 3.5M) were made and tested.

For comparison purposes, a slurry coating and drying procedure was performed to produce a conventional electrode. An anode and a cathode, and a separator disposed between the two electrodes, were then assembled and encapsulated in an Al plastic laminate encapsulation envelope, and then injected with liquid electrolyte to form a prior art lithium battery cell. The cell test results are summarized in example 19.

Example 9: v as an example of a transition metal oxide cathode active material for a lithium battery₂O₅

V alone₂O₅Powders are commercially available. To prepare graphene-loaded V₂O₅Powder samples, in a typical experiment, were prepared by mixing V₂O₅Mixing in an aqueous solution of LiCl to obtain a vanadium pentoxide gel. Li obtained by interaction with LiCl solution (Li: V molar ratio kept at 1:1)⁺The exchange gel was mixed with the GO suspension and then placed in a teflon lined stainless steel 35ml autoclave, sealed, and heated up to 180 ℃ for 12 h. After such hydrothermal treatment, the green solid was collected, thoroughly washed, sonicated for 2 minutes, and dried at 70 ℃ for 12 hours, then mixed with another 0.1% GO in water, sonicated to decompose the nanobelt size, and then spray dried at 200 ℃ to obtain graphene-surrounded composite microparticles.

Then V is put₂O₅Powder (with carbon black powder as conductive additive) and graphene loaded V₂O₅Using the slurry of the invention into the foam pores of the cathode current collector, both of the powders being used separately with the liquid electrolyteBoth the procedure and the conventional slurry coating, drying and lamination procedures are incorporated into the cell.

Example 10: LiCoO as an example of a lithium transition metal oxide cathode active material for lithium ion batteries₂

Commercially available LiCoO₂Powders and multi-walled carbon nanotubes (MW-CNTs) are dispersed in a liquid electrolyte to form a quasi-solid electrode. Two types of quasi-solid anodes were prepared to be coupled to the cathode. One containing graphite particles as an anode active material and the other containing graphene-surrounded Si nanoparticles as an anode active material. The electrolyte used was EC-VC (80/20 ratio). Each cell contains a quasi-solid anode, a separator layer, and a quasi-solid cathode assembled together and then hermetically sealed.

On a separate basis, LiCoO₂The powder, carbon black powder and PVDF resin binder were dispersed in NMP solvent to form a slurry, which was coated on both sides of an Al foil current collector and then dried under vacuum to form a cathode layer. Graphite particles and a PVDF resin binder were dispersed in an NMP solvent to form a slurry, which was coated on both sides of a Cu foil current collector and then dried under vacuum to form an anode layer. The anode layer, separator, cathode layer were then laminated and encapsulated in an Al plastic housing, into which a liquid electrolyte was injected to form a conventional lithium ion battery.

Example 11: organic material (Li) as cathode active material of lithium metal battery₂C₆O₆)

To synthesize dilithium rhodizonate (Li)₂C₆O₆) Rhodobrown acid dihydrate (species 1 in the scheme below) was used as precursor. Basic lithium salt Li₂CO₃Can be used for neutralizing two enedioic acid (enedioic acid) functional groups in an aqueous medium. Strictly stoichiometric amounts of the two reactants (rhodoleic acid and lithium carbonate) were allowed to react for 10 hours to achieve a yield of 90%. Dilithium rhodizonate (species 2) is readily soluble even in small amounts of water, which means that there are water molecules in species 2. Water was removed in vacuo at 180 ℃ for 3 hours to give the anhydrous form (species 3).

Cathode active material (Li)₂C₆O₆) And a conductive additive (carbon black, 15%) were ball milled for 10 minutes and the resulting blend was milled to produce composite particles. The electrolyte was 1M lithium hexafluorophosphate (LiPF) in PC-EC₆)。

It can be noted that formula Li₂C₆O₆Are part of a fixed structure and they do not participate in reversible lithium ion storage and release. This means that lithium ions must come from the anode side. Thus, a lithium source (e.g., lithium metal or lithium metal alloy) must be present at the anode. As shown in fig. 1(D), the anode current collector (Cu foil) is deposited with a lithium layer (e.g., by sputtering or electrochemical plating, or by using a lithium foil). This was followed by assembly of the lithium coating layer, porous separator, and quasi-solid cathode into a cell. Mixing a cathode active material and a conductive additive (Li)₂C₆O₆the/C composite particles) are dispersed in the liquid electrolyte. For comparison, corresponding conventional Li metal cells were also fabricated by conventional slurry coating, drying, lamination, encapsulation and electrolyte injection procedures.

Example 12: metal naphthalocyanine-RGO hybrid cathode for lithium metal batteries

Copper phthalocyanine (CuPc) coated graphene sheets were obtained by evaporating CuPc in a chamber along with a graphene film (5nm) prepared from a spin-coated RGO-water suspension. The resulting coated film was cut and ground to produce CuPc-coated graphene sheets, which were used as cathode active materials in lithium metal batteries having lithium metal foils as anode active materials and 1.0M and 3.0M LiClO in Propylene Carbonate (PC) solutions as electrolytes₄。

Example 13: MoS as cathode active material for lithium metal batteries₂Preparation of/RGO hybrid materials

In this example, various inorganic materials were studied. For example, by (NH)₄)₂MoS₄And hydrazine in N, N-Dimethylformamide (DMF) solution of Graphene Oxide (GO) at 200 ℃ to synthesize ultrathin MoS₂the/RGO hybrid. In a typical procedure, 22mg of (NH)₄)₂MoS₄To 10mg GO dispersed in 10ml DMF. The mixture was sonicated at room temperature for approximately 10min until a clear and homogeneous solution was obtained. Thereafter, 0.1ml of N was added₂H₄·H₂And O. The reaction solution was further sonicated for 30min before transferring into a 40mL teflon lined autoclave. The system was heated in an oven at 200 ℃ for 10 h. The product was collected by centrifugation at 8000rpm for 5min, washed with DI water and re-collected by centrifugation. The washing step was repeated at least 5 times to ensure removal of most of the DMF. Finally, the dried product is mixed with some carbon fibers and a quasi-solid electrolyte to form a deformable quasi-solid cathode.

Example 14: two-dimensional (2D) layered Bi₂Se₃Preparation of chalcogenide nanoribbons

(2D) Layered Bi₂Se₃The preparation of chalcogenide nanoribbons is well known in the art. For example, growing Bi using the vapor-liquid-solid (VLS) method₂Se₃A nanoribbon. On average, the nanoribbons produced herein are 30-55nm thick, with widths and lengths ranging from hundreds of nanometers to several microns. The longer nanobelts were subjected to ball milling to reduce the lateral dimensions (length and width) to below 200 nm. The nanoribbons prepared by these procedures and graphene sheets or expanded graphite flakes are combined with a quasi-solid electrolyte to form a deformable cathode for a lithium metal battery.

Example 15: MXene powder + chemically activated RGO

MXene is selected from metal carbides such as Ti₃AlC₂Is partially etched away from certain elements. For example, 1M NH is used at room temperature₄HF₂Aqueous solution as Ti₃AlC₂The etchant of (1). Typically, MXene surfaces are terminated with O, OH and/or F groups, why they are often referred to as M_n+1X_nT_xWhich isWherein M is the preceding transition metal, X is C and/or N, T represents a capping group (O, OH and/or F), N is 1,2 or 3, and X is the number of capping groups. MXene materials of interest include Ti₂CT_x、Nb₂CT_x、V₂CT_x、Ti₃CNT_xAnd Ta₄C₃T_x. Typically, 35% -95% MXene and 2% -35% graphene sheets are mixed in a quasi-solid electrolyte to form a quasi-solid cathode.

Example 16: graphene-loaded MnO₂Preparation of cathode active Material

MnO₂The powder was synthesized by two methods, each with or without graphene sheets present. In one method, 0.1mol/L KMnO is prepared by dissolving potassium permanganate in deionized water₄An aqueous solution. While 13.32g of a high purity sodium bis (2-ethylhexyl) sulfosuccinate surfactant was added to 300mL of isooctane (oil) and stirred well to obtain an optically clear solution. Then, 32.4mL of 0.1mol/L KMnO was added₄The solution and a selected amount of GO solution were added to the solution, which was sonicated for 30min to prepare a dark brown precipitate. The product was isolated, washed several times with distilled water and ethanol and dried at 80 ℃ for 12 h. The sample is graphene-supported MnO in powder form₂Dispersed in a CNT-containing electrolyte to form a quasi-solid cathode electrode.

Example 17: graphene-enhanced nano-silicon as anode active material for lithium ion battery

Graphene-coated Si particles are available from anchorine intense energy company (angstrom energyco, Dayton, Ohio). The quasi-solid anode electrode is prepared by the following steps: pristine graphene sheets (as conductive filaments) were dispersed in a PC-DOL (50/50 ratio) mixture, followed by graphene-coated Si particles (anode active material) and 2.5M lithium hexafluorophosphate (LiPF) at 60 ℃₆) Dissolved in the mixture solvent. Then, DOL was removed to obtain a mixture containing about 5.0M LiPF in PC₆The quasi-solid electrolyte of (1). Since LiPF is known at room temperature₆The maximum solubility in PC is less than 3.0M, so this is soLiPF₆Is in an oversaturated state.

Example 18: cobalt oxide (Co) as anode active material₃O₄) Microparticles

Despite the LiCoO₂Is a cathode active material, Co₃O₄Is an anode active material of a lithium ion battery because of LiCoO₂In relation to Li/Li⁺Electrochemical potential of about +4.0 volts, and Co₃O₄In relation to Li/Li⁺An electrochemical potential of about +0.8 volts.

Adding proper amount of inorganic salt Co (NO)₃)₂·6H₂O and subsequent ammonia solution (NH)₃·H₂O, 25 wt.%) was slowly added to the GO suspension. The resulting precursor suspension was stirred under a stream of argon for several hours to ensure complete reaction. Mixing the obtained Co (OH)₂The graphene precursor suspension is divided into two parts. A portion was filtered and dried under vacuum at 70 ℃ to obtain Co (OH)₂A graphene composite precursor. The precursor was calcined in air at 450 ℃ for 2h to form a layered Co₃O₄Graphene composite material, said composite material being characterized by having Co superposed on each other₃O₄Coated graphene sheets.

Example 19: graphene-enhanced tin oxide microparticles as anode active materials

Using the following procedure with SnCl₄·5H₂Controlled hydrolysis of O with NaOH to obtain tin oxide (SnO)₂) Nano-particles: SnCl₄·5H₂O (0.95g, 2.7m-mol) and NaOH (0.212g, 5.3m-mol) were each dissolved in 50mL of distilled water. The NaOH solution was added dropwise to the tin chloride solution at a rate of 1mL/min with vigorous stirring. The solution was homogenized by sonication for 5 min. Subsequently, the resulting hydrosol was reacted with GO dispersion for 3 hours. To the mixed solution was added a few drops of 0.1M H₂SO₄To flocculate the product. The precipitated solid was collected by centrifugation, washed with water and ethanol and dried in vacuo. The dried product was heat-treated at 400 ℃ for 2h under an Ar atmosphere and used as an anode active material.

Example 20: preparation and electrochemical testing of various battery cells

For most of the anode and cathode active materials studied, we used both the inventive method and the conventional method to prepare lithium ion or lithium metal cells.

In the case of conventional processes, a typical anode composition comprises 85 wt.% active material (e.g., Si-or Co) dissolved in N-methyl-2-pyrrolidone (NMP)₃O₄Coated graphene sheets), 7 wt.% acetylene black (Super-P) and 8 wt.% polyvinylidene fluoride binder (PVDF, 5 wt.% solids content). After coating the slurry on the Cu foil, the electrode was dried at 120 ℃ for 2h in vacuo to remove the solvent. In the case of the process of the present invention, a binder resin is typically not needed or used, thereby saving 8% by weight (reduced amount of inactive material). A cathode layer was prepared in a similar manner (using Al foil as the cathode current collector) using conventional slurry coating and drying procedures. The anode layer, separator layer (e.g., Celgard2400 membrane), and cathode layer are then laminated together and placed in a plastic-Al envelope. For example, the cells were then infused with 2.8M LiPF dissolved in a mixture of Ethylene Carbonate (EC) and diethyl carbonate (DEC) (EC-DEC, 1:1v/v)₆An electrolyte solution. In some cells, ionic liquids are used as the liquid electrolyte. The cell assembly was made in an argon filled glove box.

In the method of the present invention, preferably, the quasi-solid anode, the porous separator, and the quasi-solid cathode are assembled in a protective housing. The bag is then sealed.

Cyclic Voltammetry (CV) measurements were performed using an Abin electrochemical workstation at a typical scan rate of 1 mV/s. In addition, the electrochemical performance of each cell was also evaluated by constant current charge/discharge cycling at current densities from 50mA/g to 10A/g. For long-term cycling tests, a multi-channel battery tester manufactured by LAND was used.

In the lithium ion battery industry, it is common practice to define the cycle life of a battery as the number of charge-discharge cycles that the battery suffers a 20% capacity fade, based on the initial capacity measured after the desired electrochemical formation.

Example 21: representative test results

For each sample, several current densities (representing charge/discharge rates) were applied to determine the electrochemical response, allowing the energy density values and power density values required to construct a ravigneaux plot (power density versus energy density) to be calculated. The ravigneaux plot (gravimetric power density versus energy density) for a lithium ion battery cell containing graphite particles as the anode active material and carbon-coated LFP particles as the cathode active material is shown in fig. 7. Three of the 4 data curves are for cells prepared according to embodiments of the present invention (with sequences S1, S2, and S3, respectively), while the remaining one is a cell prepared by conventional electrode paste coating (roll coating). From these data several important observations can be drawn:

the gravimetric energy density and power density of lithium ion battery cells prepared by the method of the present invention are both significantly higher than the gravimetric energy density and power density of their counterparts (denoted "conventional") prepared by conventional roll coating methods. The change from 160 μm anode thickness (coated on a flat solid Cu foil) to 315 μm thickness and the corresponding change of the cathode to maintain the balanced capacity ratio resulted in an increase in gravimetric energy density from 165Wh/kg to 230Wh/kg (S1), 235Wh/kg (S2), and 264Wh/kg (S3), respectively. It is also surprising that batteries containing the quasi-solid electrodes of the invention with a 3D network of electron conducting pathways (due to percolation of the conductive filaments) give significantly higher energy densities and higher power densities.

These large differences cannot be simply attributed to the increase in electrode thickness and mass loading. The differences may be due to the significantly higher active material mass loading (not only mass loading) and higher conductivity associated with the cells of the invention, the reduced proportion of non-contributing (inactive) components relative to the active material weight/volume, and the unexpectedly better utilization of the electrode active material (most if not all of the graphite particles and LFP particles contribute to lithium ion storage capacity due to higher conductivity and the absence of drying pockets or dead spots in the electrode, especially under high charge/discharge rate conditions).

Fig. 8 shows the ralong plots (gravimetric power density versus gravimetric energy density) for two cells, both containing graphene-surrounded Si nanoparticles as anode active material and LiCoO₂The nanoparticles serve as a cathode active material. Experimental data were obtained from Li-ion battery cells prepared by the method of the invention and Li-ion battery cells prepared by conventional electrode slurry coating.

These data indicate that the gravimetric energy density and power density of battery cells prepared by the inventive method are significantly higher than their counterparts prepared by conventional methods. Also, the differences are large. The conventionally prepared cells exhibited a gravimetric energy density of 265Wh/kg, but the cells of the present invention were given an energy density of 393Wh/kg (S1) and 421Wh/kg (S3), respectively. For lithium ion batteries, power densities of up to 1425W/kg and 1,654W/kg are also unprecedented.

These energy density and power density differences are primarily due to the high active material mass loading (in the anode) associated with the cells of the present invention>25mg/cm²And in the cathode>45mg/cm²) And high electrode conductivity, reduced proportion of non-contributing (inactive) components relative to the active material weight/volume, and the ability of the inventive method to better utilize the active material particles (all particles being liquid electrolyte and accessible by fast ionic and electronic kinetics).

FIG. 9 shows dilithium rhodizonate (Li) containing a lithium foil as an anode active material₂C₆O₆) As a cathode active material and a lithium salt (LiPF)₆) Latte plot of lithium metal batteries with PC/DEC as organic electrolyte (both 1.5M and 5.0M). Quasi-solid electrodes were prepared according to the sequences S2 and S3 as described in example 8. The data are for three lithium metal cells prepared by the method of the invention and lithium metal cells prepared by conventional electrode slurry coating.

These data indicate that the gravimetric energy density and power density of lithium metal cells prepared by the inventive process are significantly higher than their counterparts prepared by conventional processes. Again, the differences are large and may be due to the significantly higher active material mass loading (not just mass loading) and higher conductivity associated with the electrodes of the invention, the reduced proportion of non-contributing (inactive) components relative to the active material weight/volume, and the unexpectedly better utilization of the electrode active material (most if not all of the active material contributes to lithium ion storage capacity due to higher conductivity and no dry pockets or dead spots in the electrode, especially under high charge/discharge rate conditions).

Quite noteworthy and unexpected are the following observations: the gravimetric energy density of the lithium metal-organic cathode cells of the present invention is as high as 515Wh/kg, higher than that reported for all rechargeable lithium metal or lithium ion batteries (recall that current Li-ion batteries store 150 Wh/kg based on total cell weight). Furthermore, for lithium batteries based on organic cathode active materials, a gravimetric power density of 1,576W/kg is not conceivable. Cells containing quasi-solid electrodes prepared according to sequence 3 exhibited significantly higher energy and power densities than cells of conventional sequence S2. In addition, higher concentrations of electrolyte (quasi-solid electrolyte) are surprisingly more favorable for achieving higher energy and power densities.

The above performance characteristics of lithium batteries are also observed with respect to the corresponding sodium batteries. Due to the page limitation, data for the sodium cell is no longer presented here. However, for example, fig. 10 indicates the ralong plots for two sodium ion capacitors, each containing pre-sodiated hard carbon particles as the anode active material and graphene sheets as the cathode active material; one cell has an anode prepared by a conventional slurry coating process and the other cell has a quasi-solid anode prepared according to the method of the invention. Also, quasi-solid electrode based cells give significantly higher energy densities and higher power densities. Lithium ion capacitors were found to follow a similar trend.

It is important to note that reporting the energy density and power density per weight of active material alone on a raleigh graph, as made by many researchers, may not give a realistic picture of the performance of an assembled supercapacitor cell. The weight of the other apparatus components must also be taken into account. These non-contributing components, including current collectors, electrolytes, separators, adhesives, connectors, and encapsulants, are inactive materials and do not contribute to charge storage. They merely add weight and bulk to the device. Therefore, it is desirable to reduce the relative proportion of the weight of the non-contributing components and increase the proportion of the active material. However, this goal has not been possible using conventional battery production methods. The present invention overcomes this long standing most serious problem in the field of lithium batteries.

In commercial lithium ion batteries having an electrode thickness of 100-200 μm, the weight proportion of anode active material (e.g., graphite or carbon) in the lithium ion battery is typically from 12% to 17%, and the weight proportion of cathode active material (for inorganic materials, such as LiMn₂O₄) From 22% to 41%, or from 10% to 15% for organic or polymeric materials. Therefore, a factor of 3 to 4 is often used to extrapolate the energy density or power density of the device (cell) from the characteristics based solely on the weight of the active material. In most scientific papers, the reported properties are typically based on the weight of the active material alone, and the electrodes are typically very thin (<<100 μm, and most<<50 μm). The active material weight is typically from 5% to 10% of the total device weight, which means that the actual cell (device) energy density or power density can be obtained by dividing the corresponding value based on the active material weight by a factor of 10 to 20. Taking this factor into account, the properties reported in these papers do not actually look better than those of commercial batteries. Therefore, great care must be taken in reading and interpreting the performance data of batteries reported in scientific papers and patent applications.

Claims (88)

1. An alkali metal cell, comprising:

(a) a quasi-solid cathode comprising about 30% to about 95% by volume of a cathode active materialFrom about 5% to about 40% of a first electrolyte comprising an alkali metal salt dissolved in a solvent, and from about 0.01% to about 30% by volume of a conductive additive, wherein the conductive additive comprising conductive filaments forms a 3D network of electron conducting pathways, whereby the quasi-solid electrode has from about 10^-6A conductivity of S/cm to about 300S/cm;

(b) an anode; and

(c) an ion-conducting membrane or porous separator disposed between the anode and the quasi-solid cathode; wherein the quasi-solid cathode has a thickness of not less than 200 μm.

2. The alkali metal cell of claim 1, wherein the anode comprises a quasi-solid anode comprising from about 30% to about 95% by volume of an anode active material, from about 5% to about 40% by volume of a second electrolyte comprising an alkali metal salt dissolved in a solvent, and from about 0.01% to about 30% by volume of a conductive additive, wherein the conductive additive comprising conductive filaments forms a 3D network of electron conduction pathways, such that the quasi-solid electrode has from about 10^-6A conductivity of S/cm to about 300S/cm; wherein the quasi-solid anode has a thickness of not less than 200 μm.

3. An alkali metal cell, comprising:

(a) a quasi-solid anode comprising from about 30% to about 95% by volume of an anode active material, from about 5% to about 40% by volume of an electrolyte comprising an alkali metal salt dissolved in a solvent, and from about 0.01% to about 30% by volume of a conductive additive, wherein the conductive additive comprising conductive filaments forms a 3D network of electron conducting pathways, whereby the quasi-solid electrode has from about 10^-6A conductivity of S/cm to about 300S/cm;

(b) a cathode; and

(c) an ion-conducting membrane or porous separator disposed between the anode and the quasi-solid cathode; wherein the quasi-solid cathode has a thickness of not less than 200 μm.

4. The alkali metal cell of claim 1, wherein the first electrolyte is a quasi-solid electrolyte comprising a lithium or sodium salt dissolved in a liquid solvent, having a salt concentration of not less than 2.5M.

5. The alkali metal cell of claim 2, wherein the first electrolyte or the second electrolyte is a quasi-solid electrolyte comprising a lithium salt or a sodium salt dissolved in a liquid solvent, having a salt concentration of not less than 2.5M.

6. The alkali metal cell of claim 3, wherein the electrolyte is a quasi-solid electrolyte comprising a lithium or sodium salt dissolved in a liquid solvent, having a salt concentration of not less than 2.5M.

7. The alkali metal cell of claim 1, wherein the first electrolyte is a quasi-solid electrolyte comprising a lithium or sodium salt dissolved in a liquid solvent, having a salt concentration of from 3.0M to 14M.

8. The alkali metal cell of claim 2, wherein the first electrolyte or the second electrolyte is a quasi-solid electrolyte comprising a lithium salt or a sodium salt dissolved in a liquid solvent, having a salt concentration of from 3.0M to 14M.

9. The alkali metal cell of claim 3, wherein the electrolyte is a quasi-solid electrolyte comprising a lithium or sodium salt dissolved in a liquid solvent, having a salt concentration of from 3.0M to 14M.

10. The alkali metal cell of claim 1, wherein the conductive filament is selected from a carbon fiber, a graphite fiber, a carbon nanofiber, a graphite nanofiber, a carbon nanotube, an acicular coke, a carbon whisker, a conductive polymer fiber, a conductive material coated fiber, a metal nanowire, a metal fiber, a metal wire, a graphene sheet, an expanded graphite platelet, a combination thereof, or a combination thereof with a non-filament conductive particle.

11. The alkali metal cell of claim 1, wherein the electrode retention is from about 10^-5A conductivity of S/cm to about 100S/cm.

12. The alkali metal cell of claim 1, wherein the electrode retention is from about 10^-3A conductivity of S/cm to about 10S/cm.

13. The alkali metal cell of claim 1, wherein the electrode retention is from about 10^-2A conductivity of S/cm to about 10S/cm.

14. The alkali metal cell of claim 1, wherein the conductive filaments are bonded together at intersections between the conductive filaments by a resin.

15. The alkali metal cell of claim 1, wherein the quasi-solid cathode comprises about 0.1% to about 20% by volume of a conductive additive.

16. The alkali metal cell of claim 1, wherein the quasi-solid cathode comprises about 1% to about 10% by volume of a conductive additive.

17. The alkali metal cell of claim 1, wherein the active material is in an amount from about 40% to about 90% by volume of the electrode material.

18. The alkali metal cell of claim 1, wherein the active material is in an amount from about 50% to about 85% by volume of the electrode material.

19. The alkali metal cell of claim 1, wherein the active material is in an amount from about 50% to about 75% by volume of the electrode material.

20. The alkali metal cell of claim 1, wherein the first electrolyte is in a supersaturated state.

21. The alkali metal cell of claim 2, wherein the first electrolyte or the second electrolyte is in a supersaturated state.

22. The alkali metal cell of claim 1, wherein the first electrolyte comprises an aqueous liquid, an organic solvent, an ionic liquid, or a mixture of an organic solvent and an ionic liquid.

23. The alkali metal cell of claim 2, wherein the first electrolyte or the second electrolyte comprises an aqueous liquid, an organic solvent, an ionic liquid, or a mixture of an organic solvent and an ionic liquid.

24. The alkali metal cell of claim 2, wherein the alkali metal cell is a lithium metal cell, a lithium ion cell, or a lithium ion capacitor cell and the anode active material is selected from the group consisting of:

(a) particles of lithium metal or lithium metal alloy;

(b) natural graphite particles, artificial graphite particles, mesocarbon microbeads (MCMB), carbon particles, needle coke, carbon nanotubes, carbon nanofibers, carbon fibers, and graphite fibers;

(c) silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), nickel (Ni), cobalt (Co), manganese (Mn), titanium (Ti), iron (Fe), and cadmium (Cd);

(d) alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al or Cd with other elements, wherein the alloys or compounds are stoichiometric or non-stoichiometric;

(e) oxides, carbides, nitrides, sulfides, phosphides, selenides, and tellurides of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, Ni, Co, Ti, Mn, or Cd, and mixtures or composites thereof;

(f) a prelithiated version thereof;

(g) pre-lithiated graphene sheets; and

combinations thereof.

25. The alkali metal cell of claim 24, wherein the pre-lithiated graphene sheets are selected from pre-lithiated versions of pristine graphene, graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, boron-doped graphene, nitrogen-doped graphene, chemically functionalized graphene, physically or chemically activated or etched versions thereof, or combinations thereof.

26. The alkali metal cell of claim 2, wherein the alkali metal cell is a sodium metal cell or a sodium ion cell and the anode active material comprises an alkali intercalation compound selected from: petroleum coke, carbon black, amorphous carbon, activated carbon, hard carbon, soft carbon, template carbon, hollow carbon nanowire, hollow carbon sphere, titanate, NaTi₂(PO₄)₃、Na₂Ti₃O₇、Na₂C₈H₄O₄、Na₂TP、Na_xTiO₂(x ═ 0.2 to 1.0), Na₂C₈H₄O₄Materials based on carboxylic acid salts, C₈H₄Na₂O₄、C₈H₆O₄、C₈H₅NaO₄、C₈Na₂F₄O₄、C₁₀H₂Na₄O₈、C₁₄H₄O₆、C₁₄H₄Na₄O₈Or a combination thereof.

27. The alkali metal cell of claim 2, wherein the alkali metal cell is a sodium metal cell, a sodium ion cell, or a sodium ion capacitor and the anode active material is selected from the group consisting of:

a) particles of sodium metal or sodium metal alloy;

b) natural graphite particles, artificial graphite particles, mesocarbon microbeads (MCMB), carbon particles, needle coke, carbon nanotubes, carbon nanofibers, carbon fibers, and graphite fibers;

c) sodium-doped silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), titanium (Ti), cobalt (Co), nickel (Ni), manganese (Mn), cadmium (Cd), and mixtures thereof;

d) sodium-containing alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Co, Ni, Mn, Cd, and mixtures thereof;

e) sodium-containing oxides, carbides, nitrides, sulfides, phosphides, selenides, tellurides, or antimonides of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, Ti, Co, Ni, Mn, Cd, and mixtures or composites thereof;

f) a sodium salt;

g) graphene sheets pre-loaded with sodium ions; and combinations thereof.

28. The alkali metal cell of claim 1, wherein the alkali metal cell is a lithium metal cell or a lithium ion cell and the cathode active material contains a lithium intercalation compound selected from the group consisting of: lithium cobalt oxide, doped lithium cobalt oxide, lithium nickel oxide, doped lithium nickel oxide, lithium manganese oxide, doped lithium manganese oxide, lithium vanadium oxide, doped lithium vanadium oxide, lithium mixed metal oxide, lithium iron phosphate, lithium vanadium phosphate, lithium manganese phosphate, lithium mixed metal phosphate, metal sulfides, and combinations thereof.

29. The alkali metal cell of claim 1, wherein the alkali metal cell is a lithium metal cell or a lithium ion cell and the cathode active material comprises a lithium intercalation compound or a lithium absorption compound selected from: inorganic materials, organic or polymeric materials, metal oxide/phosphate/sulfide, or combinations thereof.

30. The alkali metal cell of claim 29, wherein the metal oxide/phosphate/sulfide is selected from lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium vanadium oxide, lithium mixed metal oxide, lithium iron phosphate, lithium manganese phosphate, lithium vanadium phosphate, lithium mixed metal phosphate, transition metal sulfide, or a combination thereof.

31. The alkali metal cell of claim 29, wherein the inorganic material is selected from sulfur, a sulfur compound, lithium polysulfide, a transition metal dichalcogenide, a transition metal trichalcogenide, or a combination thereof.

32. The alkali metal cell of claim 29, wherein the inorganic material is selected from TiS₂、TaS₂、MoS₂、NbSe₃、MnO₂、CoO₂Iron oxide, vanadium oxide, or a combination thereof.

33. The alkali metal cell of claim 29, wherein the metal oxide/phosphate/sulfide comprises a vanadium oxide selected from the group consisting of: VO (vacuum vapor volume)₂、Li_xVO₂、V₂O₅、Li_xV₂O₅、V₃O₈、Li_xV₃O₈、Li_xV₃O₇、V₄O₉、Li_xV₄O₉、V₆O₁₃、Li_xV₆O₁₃Doped forms thereof, derivatives thereof, and combinations thereof, wherein 0.1<x<5。

34. The alkali metal cell of claim 29, wherein the metal oxide/phosphate/sulfide is selected from the group consisting of layered compounds LiMO₂Spinel type compound LiM₂O₄Olivine-type compound LiMPO₄Silicate compound Li₂MSiO₄Lithium iron phosphate Hydroxyphosphorus Compound LiMPO₄F. Borate saltCompound LiMBO₃Or combinations thereof, wherein M is a transition metal or a mixture of transition metals.

35. The alkali metal cell of claim 29, wherein the inorganic material is selected from: (a) bismuth selenide or bismuth telluride, (b) a di-or tri-chalcogenide of a transition metal, (c) a sulfide, selenide, or telluride of niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, cobalt, manganese, iron, nickel, or a transition metal; (d) boron nitride, or (e) a combination thereof.

36. An alkali metal cell according to claim 29, wherein the organic or polymeric material is selected from poly (anthraquinone sulfide) (PAQS), lithium oxycarbide, 3,4,9, 10-perylenetetracarboxylic dianhydride (PTCDA), poly (anthraquinone sulfide), pyrene-4, 5,9, 10-tetraone (PYT), polymer-bonded PYT, quinone (triazene), redox active organic material, Tetracyanoquinodimethane (TCNQ), Tetracyanoethylene (TCNE), 2,3,6,7,10, 11-Hexamethoxytriphenylene (HMTP), poly (5-amino-1, 4-dihydroxyanthraquinone) (PADAQ), phosphazene disulfide polymer ([ (NPS)₂)₃]n), lithiated 1,4,5, 8-naphthalenetetraol formaldehyde polymers, Hexaazatrinaphthalene (HATN), hexaazatrinexanenitrile (HAT (CN)₆) 5-benzylidenehydantoin, isatin lithium salt, pyromellitic diimide lithium salt, tetrahydroxy-p-benzoquinone derivative (THQLi)₄) N, N ' -diphenyl-2, 3,5, 6-tetraone piperazine (PHP), N ' -diallyl-2, 3,5, 6-tetraone piperazine (AP), N ' -dipropyl-2, 3,5, 6-tetraone piperazine (PRP), thioether polymers, quinone compounds, 1, 4-benzoquinone, 5,7,12, 14-Pentacenetetraone (PT), 5-amino-2, 3-dihydro-1, 4-dihydroxyanthraquinone (ADDAQ), 5-amino-1, 4-dihydroxyanthraquinone (ADAQ), quinoid calixarenes, Li₄C₆O₆、Li₂C₆O₆、Li₆C₆O₆Or a combination thereof.

37. The alkali metal cell of claim 36, wherein, the thioether polymer is selected from poly [ methanetrinitrobenzylnitroamine-tetrakis (thiomethylene) ] (PMTTM), poly (2, 4-dithiopentene) (PDTP), a polymer containing poly (ethylene-1, 1,2, 2-tetrathiol) (PETT) as a main chain thioether polymer, a side chain thioether polymer having a main chain composed of conjugated aromatic moieties and having thioether side chains as side chains, poly (2-phenyl-1, 3-dithiolane) (PPDT), poly (1, 4-bis (1, 3-dithiolane-2-yl) benzene) (PDDTB), poly (tetrahydrobenzodithiophene) (PTHBDT), poly [1,2,4, 5-tetrakis (propylthio) benzene ] (PTKPTB), or poly [3,4 (ethylenedithio) thiophene ] (PEDTT).

38. The alkali metal cell of claim 29, wherein the organic material comprises a phthalocyanine compound selected from the group consisting of: copper phthalocyanine, zinc phthalocyanine, tin phthalocyanine, iron phthalocyanine, lead phthalocyanine, nickel phthalocyanine, vanadyl phthalocyanine, fluorochrome phthalocyanine, magnesium phthalocyanine, manganese phthalocyanine, dilithium phthalocyanine, aluminum phthalocyanine chloride, cadmium phthalocyanine, chlorogallium phthalocyanine, cobalt phthalocyanine, silver phthalocyanine, metal-free phthalocyanines, chemical derivatives thereof, or combinations thereof.

39. The alkali metal cell of claim 29, wherein the lithium intercalation compound or lithium-absorbing compound is selected from a metal carbide, a metal nitride, a metal boride, a metal dichalcogenide, or a combination thereof.

40. The alkali metal cell of claim 29, wherein the lithium intercalation compound or lithium-absorbing compound is selected from an oxide, dichalcogenide, trichalcogenide, sulfide, selenide, or telluride of niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, vanadium, chromium, cobalt, manganese, iron, or nickel in nanowire, nanodisk, nanoribbon, or nanoplatelet form.

41. The alkali metal cell of claim 29, wherein the lithium intercalation compound or lithium-absorbing compound is selected from nanodiscs, nanoplatelets, nanocoatings, or nanoplatelets of an inorganic material selected from: (a) bismuth selenide or bismuth telluride, (b) a di-or tri-chalcogenide of a transition metal, (c) a sulfide, selenide, or telluride of niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, cobalt, manganese, iron, nickel, or a transition metal; (d) boron nitride, or (e) a combination thereof; wherein the disc, platelet or sheet has a thickness of less than 100 nm.

42. The alkali metal cell of claim 1, wherein the alkali metal cell is a sodium metal cell or a sodium ion cell and the active material is a cathode active material comprising a sodium intercalation compound or a sodium absorption compound selected from: inorganic materials, organic or polymeric materials, metal oxide/phosphate/sulfide, or combinations thereof.

43. The alkali metal cell of claim 42, wherein the metal oxide/phosphate/sulfide is selected from sodium cobalt oxide, sodium nickel oxide, sodium manganese oxide, sodium vanadium oxide, sodium mixed metal oxide, sodium/potassium transition metal oxide, sodium iron phosphate, sodium/potassium iron phosphate, sodium manganese phosphate, sodium/potassium manganese phosphate, sodium vanadium phosphate, sodium/potassium vanadium phosphate, sodium mixed metal phosphate, transition metal sulfide, or a combination thereof.

44. The alkali metal cell of claim 42, wherein the inorganic material is selected from sulfur, a sulfur compound, lithium polysulfide, a transition metal dichalcogenide, a transition metal trichalcogenide, or a combination thereof.

45. The alkali metal cell of claim 42, wherein the inorganic material is selected from TiS₂、TaS₂、MoS₂、NbSe₃、MnO₂、CoO₂Iron oxide, vanadium oxide, or a combination thereof.

46. The alkali metal cell of claim 42, wherein the alkali metal cell is a sodium metal cell or a sodium ion cell and the active material is a cathode active material comprising a sodium intercalation compound selected from: NaFePO₄、Na_(1-x)K_xPO₄、Na_0.7FePO₄、Na_1.5VOPO₄F_0.5、Na₃V₂(PO₄)₃、Na₃V₂(PO₄)₂F₃、Na₂FePO₄F、NaFeF₃、NaVPO₄F、Na₃V₂(PO₄)₂F₃、Na_1.5VOPO₄F_0.5、Na₃V₂(PO₄)₃、NaV₆O₁₅、Na_xVO₂、Na_0.33V₂O₅、Na_xCoO₂、Na_2/3[Ni_{1/ 3}Mn_2/3]O₂、Na_x(Fe_1/2Mn_1/2)O₂、Na_xMnO₂、λ-MnO₂、Na_xK_(1-x)MnO₂、Na_0.44MnO₂、Na_0.44MnO₂/C、Na₄Mn₉O₁₈、NaFe₂Mn(PO₄)₃、Na₂Ti₃O₇、Ni_1/3Mn_1/3Co_1/3O₂、Cu_0.56Ni_0.44HCF、NiHCF、Na_xMnO₂、NaCrO₂、Na₃Ti₂(PO₄)₃、NiCo₂O₄、Ni₃S₂/FeS₂、Sb₂O₄、Na₄Fe(CN)₆/C、NaV_1-xCr_xPO₄F、Se_zS_y(y/z ═ 0.01 to 100), Se, foscarnosite, or a combination thereof, wherein x is from 0.1 to 1.0.

47. The alkali metal cell of claim 1, wherein the anode active material composition is greater than 15mg/cm²Electrode active material mass loading.

48. The alkali metal cell of claim 1, wherein the anode active material composition is greater than 20mg/cm²Electrode active material mass loading.

49. The alkali metal cell of claim 1, wherein the anode active material composition is greater than 30mg/cm²Electrode active material mass loading.

50. A method of making an alkali metal cell having a quasi-solid electrode, the method comprising:

(d) combining an amount of active material, an amount of electrolyte, and a conductive additive to form a deformable and conductive electrode material, wherein the conductive additive containing conductive filaments forms a 3D network of electron conducting pathways;

(e) forming the electrode material as a quasi-solid electrode, wherein the forming comprises deforming the electrode material into an electrode shape without interrupting the 3D network of electron conduction pathways, thereby causing the electrode to remain no less than 10^-6Conductivity of S/cm;

(f) forming a second electrode; and is

(g) Forming an alkali metal cell by combining the quasi-solid electrode and the second electrode.

51. The method of claim 50, wherein the electrolyte is a quasi-solid electrolyte containing a lithium or sodium salt dissolved in a liquid solvent, having a salt concentration of from 2.5M to 14M.

52. The method of claim 50, wherein the electrolyte is a quasi-solid electrolyte containing a lithium salt or a sodium salt dissolved in a liquid solvent, having a salt concentration of from 3.0M to 11M.

53. The method of claim 50, wherein the conductive filament is selected from carbon fibers, graphite fibers, carbon nanofibers, graphite nanofibers, carbon nanotubes, needle coke, carbon whiskers, conductive polymer fibers, conductive material coated fibers, metal nanowires, metal fibers, metal wires, graphene sheets, expanded graphite platelets, combinations thereof, or combinations thereof with non-filament conductive particles.

54. The method of claim 50, wherein the electrode retention is from about 10^-5A conductivity of S/cm to about 300S/cm.

55. The method of claim 50, wherein the deformable electrode material has a thickness of 1,000s^-1Is not less than about 10,000Pa-s at an apparent shear rate.

56. The method of claim 50, wherein the deformable electrode material has a thickness of 1,000s^-1Is not less than about 100,000Pa-s at an apparent shear rate.

57. The method of claim 50, wherein the active material is present in an amount of about 20% to about 95% by volume of the electrode material.

58. The method of claim 50, wherein the amount of active material comprises about 35% to about 85% by volume of the electrode material.

59. The method of claim 50, wherein the active material is present in an amount of about 50% to about 75% by volume of the electrode material.

60. The method of claim 50, wherein the combining step comprises dispersing the conductive filaments in a liquid solvent to form a homogeneous suspension, followed by adding the active material in the suspension and followed by dissolving a lithium or sodium salt in the liquid solvent of the suspension.

61. The method of claim 50, wherein the step of combining and forming the electrode material into a quasi-solid electrode comprises dissolving a lithium salt or a sodium salt in a liquid solvent to form an electrolyte having a first salt concentration and subsequently removing a portion of the liquid solvent to increase the salt concentration to obtain a quasi-solid electrolyte having a second salt concentration, the second salt concentration being higher than the first concentration and higher than 2.5M.

62. The method of claim 61, wherein the removing does not cause precipitation or crystallization of the salt and the electrolyte is in a supersaturated state.

63. The method of claim 61, wherein the liquid solvent comprises a mixture of at least a first liquid solvent and a second liquid solvent and the first liquid solvent is more volatile than the second liquid solvent, and wherein the removing a portion of the liquid solvent comprises removing the first liquid solvent.

64. The method of claim 50, wherein the alkali metal cell is a lithium metal cell or a lithium ion cell and the active material is an anode active material selected from the group consisting of:

(h) particles of lithium metal or lithium metal alloy;

(i) natural graphite particles, artificial graphite particles, mesocarbon microbeads (MCMB), carbon particles, needle coke, carbon nanotubes, carbon nanofibers, carbon fibers, and graphite fibers;

(j) silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), nickel (Ni), cobalt (Co), manganese (Mn), titanium (Ti), iron (Fe), and cadmium (Cd);

(k) alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al or Cd with other elements, wherein the alloys or compounds are stoichiometric or non-stoichiometric;

(l) Oxides, carbides, nitrides, sulfides, phosphides, selenides, and tellurides of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, Ni, Co, Ti, Mn, or Cd, and mixtures or composites thereof;

(m) a prelithiated version thereof;

(n) pre-lithiated graphene sheets; and

combinations thereof.

65. The method of claim 64, wherein the pre-lithiated graphene sheets are selected from pre-lithiated versions of pristine graphene, graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, boron-doped graphene, nitrogen-doped graphene, chemically functionalized graphene, physically or chemically activated or etched versions thereof, or combinations thereof.

66. The method of claim 50, wherein the alkali metal cell is a sodium metal cell or a sodium ion cell and the active material is an anode active material comprising an alkali intercalation compound selected from: petroleum coke, amorphous carbon, activated carbon, hard carbon, soft carbon, template carbon, hollow carbon nanowire, hollow carbon sphere, titanate, NaTi₂(PO₄)₃、Na₂Ti₃O₇、Na₂C₈H₄O₄、Na₂TP、Na_xTiO₂(x ═ 0.2 to 1.0), Na₂C₈H₄O₄Materials based on carboxylic acid salts, C₈H₄Na₂O₄、C₈H₆O₄、C₈H₅NaO₄、C₈Na₂F₄O₄、C₁₀H₂Na₄O₈、C₁₄H₄O₆、C₁₄H₄Na₄O₈Or a combination thereof.

67. The method of claim 50, wherein the alkali metal cell is a sodium metal cell or a sodium ion cell and the active material is an anode active material selected from the group consisting of:

h) particles of sodium metal or sodium metal alloy;

i) natural graphite particles, artificial graphite particles, mesocarbon microbeads (MCMB), carbon particles, needle coke, carbon nanotubes, carbon nanofibers, carbon fibers, and graphite fibers;

j) sodium-doped silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), titanium (Ti), cobalt (Co), nickel (Ni), manganese (Mn), cadmium (Cd), and mixtures thereof;

k) sodium-containing alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Co, Ni, Mn, Cd, and mixtures thereof;

l) sodium-containing oxides, carbides, nitrides, sulfides, phosphides, selenides, tellurides, or antimonides of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, Ti, Co, Ni, Mn, Cd, and mixtures or composites thereof;

m) a sodium salt;

n) graphene sheets pre-loaded with sodium ions; and combinations thereof.

68. The method of claim 50, wherein the alkali metal cell is a lithium metal cell or a lithium ion cell and the active material is a cathode active material comprising a lithium intercalation compound selected from the group consisting of: lithium cobalt oxide, doped lithium cobalt oxide, lithium nickel oxide, doped lithium nickel oxide, lithium manganese oxide, doped lithium manganese oxide, lithium vanadium oxide, doped lithium vanadium oxide, lithium mixed metal oxide, lithium iron phosphate, lithium vanadium phosphate, lithium manganese phosphate, lithium mixed metal phosphate, metal sulfides, and combinations thereof.

69. The method of claim 50, wherein the electrolyte is selected from an aqueous liquid, an organic liquid, an ionic liquid, or a mixture of an organic liquid and an ionic liquid.

70. The method of claim 50, wherein the alkali metal cells are lithium metal cells or lithium ion cells and the active material is a cathode active material comprising a lithium intercalation compound or a lithium absorbing compound selected from: inorganic materials, organic or polymeric materials, metal oxide/phosphate/sulfide, or combinations thereof.

71. The method of claim 70, wherein said metal oxide/phosphate/sulfide is selected from lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium vanadium oxide, lithium mixed metal oxide, lithium iron phosphate, lithium manganese phosphate, lithium vanadium phosphate, lithium mixed metal phosphate, transition metal sulfide, or combinations thereof.

72. The method of claim 70, wherein the inorganic material is selected from sulfur, a sulfur compound, lithium polysulfide, a transition metal dichalcogenide, a transition metal trichalcogenide, or a combination thereof.

73. The method of claim 70, wherein the inorganic material is selected from TiS₂、TaS₂、MoS₂、NbSe₃、MnO₂、CoO₂Iron oxide, vanadium oxide, or a combination thereof.

74. The method of claim 70, wherein the metal oxide/phosphate/sulfide contains a vanadium oxide selected from the group consisting of: VO (vacuum vapor volume)₂、Li_xVO₂、V₂O₅、Li_xV₂O₅、V₃O₈、Li_xV₃O₈、Li_xV₃O₇、V₄O₉、Li_xV₄O₉、V₆O₁₃、Li_xV₆O₁₃Doped forms thereof, derivatives thereof, and combinations thereof, wherein 0.1<x<5。

75. The method of claim 70, wherein the metal oxide/phosphate/sulfide is selected from the group consisting of layered compounds LiMO₂Spinel type compound LiM₂O₄Olivine-type compound LiMPO₄Silicate compound Li₂MSiO₄Lithium iron phosphate Hydroxyphosphorus Compound LiMPO₄F. Borate compound LiMBO₃Or combinations thereof, wherein M is a transition metal or a mixture of transition metals.

76. The method of claim 70, wherein the inorganic material is selected from the group consisting of: (a) bismuth selenide or bismuth telluride, (b) a di-or tri-chalcogenide of a transition metal, (c) a sulfide, selenide, or telluride of niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, cobalt, manganese, iron, nickel, or a transition metal; (d) boron nitride, or (e) a combination thereof.

77. The method of claim 70, wherein the organic or polymeric material is selected from poly (anthraquinone sulfides) (PAQS), lithium oxycarbide, 3,4,9, 10-perylenetetracarboxylic dianhydride (PTCDA), poly (anthraquinone sulfides), pyrene-4, 5,9, 10-tetraone (PYT), polymer-bonded PYT, quinone (triazenes), redox active organic materials, tetracyanoquinone-dimethane (TCNQ), Tetracyanoethylene (TCNE), 2,3,6,7,10, 11-Hexamethoxytriphenylene (HMTP), poly (5-amino-1, 4-dihydroxyanthraquinone) (PADAQ), phosphazene disulfide polymer ([ (NPS)₂)₃]n), lithiated 1,4,5, 8-naphthalenetetraol formaldehyde polymers, Hexaazatrinaphthalene (HATN), hexaazatrinexanenitrile (HAT (CN)₆) 5-benzylidenehydantoin, isatin lithium salt, pyromellitic diimide lithium salt, tetrahydroxy-p-benzoquinone derivative (THQLi)₄) N, N ' -diphenyl-2, 3,5, 6-tetraone piperazine (PHP), N ' -diallyl-2, 3,5, 6-tetraone piperazine (AP), N ' -dipropyl-2, 3,5, 6-tetraone piperazine (PRP), thioether polymers, quinone compounds, 1, 4-benzoquinone, 5,7,12, 14-Pentacenetetraone (PT), 5-amino-2, 3-dihydro-1, 4-dihydroxyanthraquinone (ADDAQ), 5-amino-1, 4-dihydroxyanthraquinone (ADAQ), quinoid calixarenes, Li₄C₆O₆、Li₂C₆O₆、Li₆C₆O₆Or a combination thereof.

78. The method of claim 77, the thioether polymer is selected from poly [ methanetrinitrobenzylnitroamine-tetrakis (thiomethylene) ] (PMTTM), poly (2, 4-dithiopentene) (PDTP), a polymer containing poly (ethylene-1, 1,2, 2-tetrathiol) (PETT) as a main chain thioether polymer, a side chain thioether polymer having a main chain composed of conjugated aromatic moieties and having thioether side chains as side chains, poly (2-phenyl-1, 3-dithiolane) (PPDT), poly (1, 4-bis (1, 3-dithiolane-2-yl) benzene) (PDDTB), poly (tetrahydrobenzodithiophene) (PTHBDT), poly [1,2,4, 5-tetrakis (propylthio) benzene ] (PTKPTB), or poly [3,4 (ethylenedithio) thiophene ] (PEDTT).

79. The method of claim 70, wherein the organic material comprises a phthalocyanine compound selected from the group consisting of: copper phthalocyanine, zinc phthalocyanine, tin phthalocyanine, iron phthalocyanine, lead phthalocyanine, nickel phthalocyanine, vanadyl phthalocyanine, fluorochrome phthalocyanine, magnesium phthalocyanine, manganese phthalocyanine, dilithium phthalocyanine, aluminum phthalocyanine chloride, cadmium phthalocyanine, chlorogallium phthalocyanine, cobalt phthalocyanine, silver phthalocyanine, metal-free phthalocyanines, chemical derivatives thereof, or combinations thereof.

80. The method of claim 70, wherein the lithium intercalation compound or lithium-absorbing compound is selected from a metal carbide, a metal nitride, a metal boride, a metal dichalcogenide, or a combination thereof.

81. The method of claim 70, wherein the lithium intercalation compound or lithium-absorbing compound is selected from an oxide, dichalcogenide, trichalcogenide, sulfide, selenide, or telluride of niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, vanadium, chromium, cobalt, manganese, iron, or nickel in nanowire, nanodisk, nanoribbon, or nanoplatelet form.

82. The method of claim 70, wherein the lithium intercalation compound or lithium-absorbing compound is selected from nanodiscs, nanoplatelets, nanocoatings, or nanoplatelets of an inorganic material selected from: (a) bismuth selenide or bismuth telluride, (b) a di-or tri-chalcogenide of a transition metal, (c) a sulfide, selenide, or telluride of niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, cobalt, manganese, iron, nickel, or a transition metal; (d) boron nitride, or (e) a combination thereof; wherein the disc, platelet or sheet has a thickness of less than 100 nm.

83. The method of claim 70, wherein the lithium intercalation compound or lithium-absorbing compound comprises nanodiscs, nanoplatelets, nanocoatings, or nanoplatelets of a lithium intercalation compound selected from the group consisting of: (i) bismuth selenide or bismuth telluride, (ii) transition metal dichalcogenides or trisulfides, (iii) sulfides, selenides, or tellurides of niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, cobalt, manganese, iron, nickel, or transition metals; (iv) (iv) boron nitride, or (v) a combination thereof, wherein the disk, platelet, coating, or sheet has a thickness of less than 100 nm.

84. The method of claim 50, wherein the alkali metal cells are sodium metal cells or sodium ion cells and the active material is a cathode active material comprising a sodium intercalation compound or a sodium absorbing compound selected from: inorganic materials, organic or polymeric materials, metal oxide/phosphate/sulfide, or combinations thereof.

85. The method of claim 84, wherein the metal oxide/phosphate/sulfide is selected from sodium cobalt oxide, sodium nickel oxide, sodium manganese oxide, sodium vanadium oxide, sodium mixed metal oxide, sodium/potassium transition metal oxide, sodium iron phosphate, sodium/potassium iron phosphate, sodium manganese phosphate, sodium/potassium manganese phosphate, sodium vanadium phosphate, sodium/potassium vanadium phosphate, sodium mixed metal phosphate, transition metal sulfide, or a combination thereof.

86. The method of claim 84, wherein the inorganic material is selected from sulfur, a sulfur compound, lithium polysulfide, a transition metal dichalcogenide, a transition metal trichalcogenide, or a combination thereof.

87. The method of claim 84, wherein the inorganic material is selected from TiS₂、TaS₂、MoS₂、NbSe₃、MnO₂、CoO₂Iron oxide, vanadium oxide, or a combination thereof.

88. The method of claim 50, wherein the alkali metal cell is a sodium metal cell or a sodium ion cell and the active material is a cathode active material comprising a sodium intercalation compound selected from: NaFePO₄、Na_(1-x)K_xPO₄、Na_0.7FePO₄、Na_1.5VOPO₄F_0.5、Na₃V₂(PO₄)₃、Na₃V₂(PO₄)₂F₃、Na₂FePO₄F、NaFeF₃、NaVPO₄F、Na₃V₂(PO₄)₂F₃、Na_1.5VOPO₄F_0.5、Na₃V₂(PO₄)₃、NaV₆O₁₅、Na_xVO₂、Na_0.33V₂O₅、Na_xCoO₂、Na_2/3[Ni_1/3Mn_2/3]O₂、Na_x(Fe_1/2Mn_1/2)O₂、Na_xMnO₂、λ-MnO₂、Na_xK_(1-x)MnO₂、Na_0.44MnO₂、Na_0.44MnO₂/C、Na₄Mn₉O₁₈、NaFe₂Mn(PO₄)₃、Na₂Ti₃O₇、Ni_1/3Mn_1/3Co_1/3O₂、Cu_0.56Ni_0.44HCF、NiHCF、Na_xMnO₂、NaCrO₂、Na₃Ti₂(PO₄)₃、NiCo₂O₄、Ni₃S₂/FeS₂、Sb₂O₄、Na₄Fe(CN)₆/C、NaV_1-xCr_xPO₄F、Se_zS_y(y/z ═ 0.01 to 100), Se, foscarnosite, or a combination thereof, wherein x is from 0.1 to 1.0.

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