CN116742134A - Electrolyte and mixed lithium-sodium ion battery comprising same - Google Patents

Electrolyte and mixed lithium-sodium ion battery comprising same Download PDF

Info

Publication number
CN116742134A
CN116742134A CN202210200220.3A CN202210200220A CN116742134A CN 116742134 A CN116742134 A CN 116742134A CN 202210200220 A CN202210200220 A CN 202210200220A CN 116742134 A CN116742134 A CN 116742134A
Authority
CN
China
Prior art keywords
electrolyte
carbonate
lithium
organic solvent
ion battery
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210200220.3A
Other languages
Chinese (zh)
Inventor
黄华文
赵伟
李素丽
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhuhai Cosmx Battery Co Ltd
Original Assignee
Zhuhai Cosmx Battery Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zhuhai Cosmx Battery Co Ltd filed Critical Zhuhai Cosmx Battery Co Ltd
Priority to CN202210200220.3A priority Critical patent/CN116742134A/en
Publication of CN116742134A publication Critical patent/CN116742134A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0569—Liquid materials characterised by the solvents
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0568—Liquid materials characterised by the solutes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0025—Organic electrolyte
    • H01M2300/0028—Organic electrolyte characterised by the solvent
    • H01M2300/0037—Mixture of solvents
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The application provides an electrolyte and a mixed lithium-sodium ion battery comprising the same. The electrolyte comprises a composite organic solvent, lithium salt and sodium salt; the composite organic solvent comprises propylene carbonate and an ether compound, wherein the mass of the propylene carbonate accounts for 10-80 wt% of the total mass of the composite organic solvent, and the mass of the ether compound accounts for 5-40 wt% of the total mass of the composite organic solvent. The PC-based and ether-based mixed electrolyte is used in the mixed lithium-sodium ion battery, so that the low-temperature performance and the normal-temperature cycling stability of the battery can be effectively improved.

Description

Electrolyte and mixed lithium-sodium ion battery comprising same
Technical Field
The application belongs to the technical field of secondary ion batteries, and particularly relates to an electrolyte and a mixed lithium-sodium ion battery comprising the same.
Background
The lithium ion battery has been widely used because of its advantages in energy density, cycle life, etc., but it is difficult to realize long-term large-scale use of the lithium ion battery due to the shortage of lithium resources. Sodium ion batteries are paid attention as a new generation energy storage system because of advantages of low theoretical cost, low temperature, excellent quick charge performance and the like, but the application fields of the sodium ion batteries are limited to a certain extent because of low theoretical energy density. Therefore, the energy storage system with low development cost and high energy density has great application value. The hybrid lithium-sodium battery is a design which can realize the complementary advantages of the lithium-ion battery and the sodium-ion battery, and the system is widely paid attention to research and development personnel after being proposed.
Similar to the structure of lithium ion batteries, hybrid lithium sodium ion batteries also consist of a positive electrode, a negative electrode, a diaphragm and electrolyte. Among them, the complex composition of the electrolyte is a key to influence the performance of the battery. However, the mixed ion battery system is still in the initial development stage, and research application on the electrolyte is still limited, so that the industrialization process of the high-performance mixed lithium-sodium ion battery is influenced.
Disclosure of Invention
In order to overcome the defects in the prior art, the application aims to provide an electrolyte and a mixed lithium-sodium ion battery comprising the electrolyte. The electrolyte can effectively improve the low-temperature performance and the normal-temperature cycling stability of the battery.
The application aims at realizing the following technical scheme:
an electrolyte comprising a complex organic solvent, a lithium salt, and a sodium salt; the composite organic solvent comprises propylene carbonate and an ether compound, wherein the mass of the propylene carbonate accounts for 10-80 wt% of the total mass of the composite organic solvent, and the mass of the ether compound accounts for 5-40 wt% of the total mass of the composite organic solvent.
According to an embodiment of the application, the electrolyte is used for mixing lithium sodium ion batteries.
According to an embodiment of the present application, the propylene carbonate accounts for 20wt% to 80wt% of the total mass of the composite organic solvent, for example, 10wt%, 20wt%, 30wt%, 40wt%, 50wt%, 60wt%, 70wt% or 80wt%.
According to an embodiment of the present application, the mass of the ether compound is 10wt% to 30wt%, for example, 5wt%, 10wt%, 20wt%, 30wt% or 40wt% of the total mass of the composite organic solvent.
According to an embodiment of the present application, the ether compound is selected from one or more of ethylene glycol dimethyl ether (DME), diethylene glycol dimethyl ether (DEGDME), triethylene glycol dimethyl ether (TRGDME), tetraethylene glycol dimethyl ether (TEGDME), fluoroether (F-EPE), fluoroether (D2), fluoroether (HFPM), fluoroether (MFE), fluoroether (EME), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), 1, 3-Dioxane (DOL), 1, 4-Dioxane (DOX) in any ratio.
According to an embodiment of the present application, the composite organic solvent further includes other solvents selected from one or more of Ethylene Carbonate (EC), butylene carbonate, difluoroethylene carbonate (DFEC), dimethyl fluorocarbonate, methylethyl fluorocarbonate, dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate, methylethyl carbonate (EMC), methyl formate, ethyl formate, propyl formate, butyl formate, methyl acetate, ethyl Acetate (EA), propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, methyl difluoroacetate, ethyl difluoroacetate, gamma-butyrolactone (GBL), gamma-valerolactone, delta-valerolactone, sulfolane, dimethyl sulfoxide (DMSO), methylene chloride, dichloroethane, in any ratio.
According to an embodiment of the application, the lithium salt is selected from lithium hexafluorophosphate (LiPF 6 ) Lithium tetrafluoroborate (LiBF) 4 ) Lithium perchlorate (LiClO) 4 ) Lithium hexafluoroarsenate (LiAsF) 6 ) Lithium hexafluoroantimonate (LiSbF) 6 ) Lithium difluorophosphate (LiPF) 2 O 2 ) 4, 5-dicyano-2-trifluoromethylimidazole Lithium (LiDTI), bis (oxalato) borate (LiBOB), bis (malonato) borate (LiBMB), lithium difluorooxalato borate (LiDFOB), lithium bis (difluoromalonato) borate (LiBDFMB), (malonato) borate (LiMOB), (difluoromalonato) borate (LiDFMOB), lithium tris (oxalato) phosphate (LiTOP), lithium tris (difluoromalonato) phosphate (LiTDFMP), lithium tetrafluorooxalato phosphate (LiTFOP), lithium difluorodioxaoxalato phosphate (LiDFOP), bis (fluorosulfonyl) imideLithium (LiFSI), lithium bis (trifluoromethanesulfonyl) imide (LiTFSI), lithium (fluorosulfonyl) (trifluoromethanesulfonyl) imide (LiN (SO) 2 F)(SO 2 CF 3 ) Lithium nitrate (LiNO) 3 ) One or more organic/inorganic salts of lithium fluoride (LiF) are mixed in any ratio.
According to an embodiment of the application, the sodium salt is selected from sodium hexafluorophosphate (NaPF 6 ) Sodium tetrafluoroborate (NaBF) 4 ) Sodium perchlorate (NaClO) 4 ) Sodium hexafluoroarsenate (NaAsF) 6 ) Sodium hexafluoroantimonate (NaSbF) 6 ) Sodium difluorophosphate (NaPF) 2 O 2 ) Sodium 4, 5-dicyano-2-trifluoromethylimidazole (NaDTI), sodium bis (oxalato) borate (NaBOB), sodium bis (malonato) borate (NaBMB), sodium difluorooxalato borate (NaDFOB), sodium bis (difluoromalonato) borate (NaBDFMB), sodium malonato (NaMOB), (difluoromalonato) borate (NaDFMOB), sodium tris (oxalato) phosphate (NaTOP), sodium tris (difluoromalonato) phosphate (NaTDFMP), sodium tetrafluorooxalate phosphate (NaTFOP), sodium difluorodioxalate phosphate (NaDFOP), sodium bis (fluorosulfonyl) imide (NaFSI), sodium bis (trifluoromethanesulfonyl) imide (NaTFSI), (fluorosulfonyl) (trifluoromethanesulfonyl) imide sodium (NaN (SO) 2 F)(SO 2 CF 3 ) Sodium nitrate (NaNO) 3 ) One or more organic/inorganic salts of sodium fluoride (NaF) are mixed in any ratio.
According to an embodiment of the present application, the concentration of the lithium salt in the electrolyte is 0.2 to 5.0mol/L, for example, 0.2mol/L, 0.5mol/L, 0.8mol/L, 1mol/L, 1.2mol/L, 1.5mol/L, 1.8mol/L, 2.0mol/L, 3.0mol/L, 4.0mol/L, or 5.0mol/L.
According to an embodiment of the present application, the concentration of the sodium salt in the electrolyte is 0.2 to 5.0mol/L, for example, 0.2mol/L, 0.5mol/L, 0.8mol/L, 1mol/L, 1.2mol/L, 1.5mol/L, 1.8mol/L, 2.0mol/L, 3.0mol/L, 4.0mol/L or 5.0mol/L.
According to an embodiment of the present application, the electrolyte may further include an additive selected from one or more of Vinylene Carbonate (VC), vinyl Ethylene Carbonate (VEC), 1, 3-propane sultone, trifluoromethyl ethylene carbonate, dimethyl sulfate, vinyl methyl sulfate, propylene sulfate, vinyl sulfite, succinic anhydride, biphenyl, diphenyl ether, toluene, xylene, cyclohexylbenzene, fluorobenzene, p-fluorotoluene, p-fluoroanisole, t-butylbenzene, t-pentylbenzene, propenolactone, butane sultone, methylene methane disulfonate, ethylene glycol bis (propionitrile) ether, hexamethyldisilazane, heptamethyldisilazane, dimethyl methylphosphonate, diethyl ethylphosphonate, trimethyl phosphate, triethyl phosphate, triphenyl phosphite, tris (trimethylsilyl) borate, tris (trimethylsilyl) phosphate, and a mixture of any ratio.
According to an embodiment of the present application, the content of the additive is 0.01wt% to 10wt% of the total mass of the electrolyte. The excessive addition of the additive can lead to incomplete dissolution in the electrolyte, and can reduce the mobility of lithium/sodium ions and sodium ions, thereby reducing the performance of the mixed lithium-sodium ion battery; the addition amount of the additive is too small to play a corresponding role. Preferably, the content of the additive is 1.0wt% to 5.0wt% of the total mass of the electrolyte.
The application also provides a mixed lithium-sodium ion battery, which comprises the electrolyte.
According to an embodiment of the present application, the use of the mixed lithium-sodium ion battery is not particularly limited, and the battery can be used for various known uses. For example: standby power, automobiles, motorcycles, electric boats, bicycles, lighting fixtures, toys, game machines, watches, electric tools, cameras, large-sized batteries for home use, energy storage power stations, and the like.
According to an embodiment of the present application, the battery cell of the lithium-sodium ion battery may be a stacked structure formed by sequentially stacking a negative electrode tab, a positive electrode tab, and a separator, or may be a wound structure formed by sequentially stacking a negative electrode tab, a positive electrode tab, and a separator and winding the stacked structure.
The application has the beneficial effects that:
the application provides an electrolyte and a mixed lithium-sodium ion battery comprising the same. The electrolyte comprises a composite organic solvent, lithium salt and sodium salt; the composite organic solvent comprises propylene carbonate and an ether compound, wherein the mass of the propylene carbonate accounts for 10-80 wt% of the total mass of the composite organic solvent, and the mass of the ether compound accounts for 5-40 wt% of the total mass of the composite organic solvent.
Propylene Carbonate (PC) has better low-temperature performance, but PC is easy to react with Li + The co-intercalation of graphite negative electrodes for lithium ion batteries can affect the stability of the electrolytic interface, resulting in a decay in battery capacity. The negative electrode used in the application is made of hard carbon material, has the characteristic of sodium storage, and has good compatibility with PC electrolyte. But the viscosity of the pure PC solvent is larger, which is unfavorable for the preparation of high conductivity, so the ionic conductivity of the electrolyte is further improved by selecting and adding the ether compound with low viscosity, and meanwhile, the ether compound is favorable for promoting the formation of stable SEI film and improving the cycle stability of the battery. Therefore, the PC-based and ether-based mixed electrolyte is used in the mixed lithium-sodium ion battery, so that the low-temperature performance and the normal-temperature cycling stability of the battery can be effectively improved.
Detailed Description
< negative plate >
The mixed lithium-sodium ion battery also comprises a negative electrode plate, wherein the negative electrode plate comprises a negative electrode active material.
Illustratively, the negative electrode sheet includes a current collector and a negative electrode active material layer; the negative electrode active material layer is coated on the surface of the current collector; the anode active material layer includes an anode active material having both a capability of storing lithium ions and a capability of storing sodium ions.
According to an embodiment of the present application, the negative electrode active material is selected from natural graphite, artificial graphite, mesophase micro carbon spheres, hard carbon, soft carbon, sn, snO, snO 2 、Sb、Sb 2 O 3 、Bi、Bi 2 O 3 And TiO 2 One or more of the following; preferably hard carbon.
According to an embodiment of the present application, the hard carbon refers to a carbon material that is difficult to graphitize at a high temperature of 2500 ℃ or higher.
According to an embodiment of the present application, the hard carbon is selected from pyrolytic carbon, and illustratively, the hard carbon is selected from at least one of resin pyrolytic carbon, organic polymer pyrolytic carbon, pyrolytic carbon black, and biomass pyrolytic carbon.
Wherein the resin in the resin pyrolytic carbon is at least one selected from phenolic resin, epoxy resin and polyfurfuryl alcohol.
Wherein the organic polymer in the organic polymer pyrolytic carbon is at least one selected from the group consisting of polypropylene alcohol, polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF) and Polyacrylonitrile (PAN).
Wherein the pyrolytic carbon black is selected from acetylene black.
Wherein the biomass in the biomass pyrolytic carbon is at least one selected from rice hulls, walnut shells, banana peels, shaddock peels, lignin and coconut shells.
According to an embodiment of the present application, the hard carbon has an average particle diameter Dv50 of 5 μm to 15 μm.
According to an embodiment of the application, the negative electrode sheet is used for a hybrid lithium sodium ion battery.
According to an embodiment of the present application, the anode active material layer further includes a conductive agent and a binder.
According to an embodiment of the present application, the conductive agent includes, but is not limited to: a carbon-based material, a metal-based material, a conductive polymer, or a mixture thereof. In some embodiments, the carbon-based material is selected from natural graphite, synthetic graphite, carbon black, acetylene black, ketjen black, carbon fiber, or any combination thereof. In some embodiments, the metal-based material is selected from the group consisting of metal powder, metal fiber, copper, nickel, aluminum, silver. In some embodiments, the conductive polymer is a polyphenylene derivative.
According to an embodiment of the present application, the current collector includes, but is not limited to: copper foil, carbon coated copper foil, perforated copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, conductive metal coated polymeric substrates, and any combination thereof.
According to an embodiment of the present application, the binder includes, but is not limited to: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), styrene-butadiene rubber (SBR), nitrile-butadiene rubber (NBR), water-based acrylic resins, polyvinyl alcohol, polyvinyl butyral, polyurethane, fluorinated rubber, carboxymethyl cellulose (CMC), polyacrylic acid (PAA), epoxy resins, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinylpyrrolidone, nylon.
According to an embodiment of the present application, the negative electrode active material layer includes the following components in percentage by mass:
75-98 wt% of negative electrode active material, 1-15 wt% of conductive agent and 1-10 wt% of binder.
Preferably, the mass percentage of each component in the anode active material layer is as follows:
82 to 96 weight percent of negative electrode active material, 2 to 10 weight percent of conductive agent and 2 to 8 weight percent of binder.
According to an embodiment of the present application, the negative electrode sheet may be prepared according to a conventional method in the art. The negative electrode active material, and optionally, the conductive agent and the binder are generally dispersed in a solvent (e.g., water) to form a uniform negative electrode slurry, and the negative electrode slurry is coated on a current collector and subjected to processes such as drying to obtain a negative electrode sheet.
< positive electrode sheet >
The mixed lithium-sodium ion battery also comprises a positive plate, wherein the positive plate comprises a positive active material.
Illustratively, the positive electrode sheet includes a current collector and a positive electrode active material layer; the positive electrode active material layer is coated on the surface of the current collector; the positive electrode active material layer includes a positive electrode active material having both a capability of storing lithium ions and a capability of storing sodium ions.
According to an embodiment of the present application, the positive electrode active material includes one or more of a transition metal layered oxide, a polyanion material, and a prussian blue-based material.
According to an embodiment of the application, the transition metal layered oxide is selected, for example, from Na [ Ni ] 0.5 Fe 0.5 ]O 2 、Na[Co 0.5 Fe 0.5 ]O 2 、Na[Ni 0.5 Co 0.5 ]O 2 、Na[Ni 1/3 Fe 1/3 Mn 1/3 ]O 2 、Na[Cu 1/9 Ni 2/9 Fe 1/3 Mn 1/3 ]O 2 Etc.
According to an embodiment of the present application, the Prussian blue material has a chemical formula a x M z [Fe(CN) 6 ] y Wherein A is an alkali metal cation, M is a transition metal cation, and x is more than or equal to 1 and less than or equal to 2,0.9, y is more than or equal to 1,0.8 and z is more than or equal to 1.
According to the embodiment of the application, the Prussian blue type material also contains crystal water. Illustratively, the Prussian blue-based material has 0 to 2 crystal waters.
According to embodiments of the present application, a may be one or more of Li, na, K, rb, cs and Fr, in particular.
According to embodiments of the application, M may be one or more of Sc, ti, V, cr, mn, fe, co, ni, cu, zr and Mo in particular.
According to an embodiment of the present application, the Prussian blue type material is selected from LiFe 2 (CN) 6 、LiCoFe(CN) 6 、LiMnFe(CN) 6 、NaFe 2 (CN) 6 、KFe 2 (CN) 6 、NaCuFe(CN) 6 、Na 1.72 Mn[Fe(CN) 6 ] 0.99 、Na 1.92 FeFe(CN) 6 、Na 1.61 Fe 1.89 (CN) 6 、NaNiFe(CN) 6 、Na 2 Fe 2 (CN) 6 、Na 2 MnFe(CN) 6 、Na 2 CoFe(CN) 6 、Na 2 NiFe(CN) 6 And the like.
According to an embodiment of the application, the polyanionic material has the chemical formula A' x’ M’ y’ (X n’ O m ) z’ F w Wherein A 'is Li and/or Na, M' is a transition metal ion of variable valence, X is one or more of P, S and Si, and X 'is not less than 1, y'>The values of 0, z 'is more than or equal to 1, w is more than or equal to 0, and n' and m accord with the chargesConservation principle.
According to an embodiment of the application, M' is one or more of Ti, V, fe and Mn.
According to an embodiment of the application, the polyanionic material is selected from the group consisting of NaFePO 4 、Na 3 V 2 (PO 4 ) 3 、Na 2 MnP 2 O 7 、Na 2 FeP 2 O 7 、Na 2 FePO 4 F、Na 3 V 2 (PO 4 ) 2 F 3 、Na 3 V 2 (PO 4 ) 2 F 3 、Na 2 Fe 2 (SO 4 ) 3 、NaTi 2 (PO 4 ) 3 And the like.
According to an embodiment of the application, the positive electrode sheet is used for a hybrid lithium sodium ion battery.
According to an embodiment of the present application, the positive electrode active material layer further includes a conductive agent and a binder.
According to an embodiment of the present application, the conductive agent includes, but is not limited to: a carbon-based material, a metal-based material, a conductive polymer, or a mixture thereof. In some embodiments, the carbon-based material is selected from natural graphite, synthetic graphite, carbon black, acetylene black, ketjen black, carbon fiber, or any combination thereof. In some embodiments, the metal-based material is selected from the group consisting of metal powder, metal fiber, copper, nickel, aluminum, silver. In some embodiments, the conductive polymer is a polyphenylene derivative.
According to an embodiment of the present application, the current collector includes, but is not limited to: aluminum foil, carbon coated aluminum foil, perforated aluminum foil, stainless steel foil, conductive metal coated polymeric substrates, and any combination thereof.
According to an embodiment of the present application, the binder includes, but is not limited to: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), styrene-butadiene rubber (SBR), nitrile-butadiene rubber (NBR), water-based acrylic resin, polyvinyl alcohol, polyvinyl butyral, polyurethane, fluorinated rubber, carboxymethyl cellulose (CMC), polyacrylic acid (PAA).
According to an embodiment of the present application, the positive electrode active material layer comprises the following components in percentage by mass:
75-98 wt% of positive electrode active material, 1-15 wt% of conductive agent and 1-10 wt% of binder.
Preferably, the positive electrode active material layer comprises the following components in percentage by mass:
82 to 96 weight percent of positive electrode active material, 2 to 10 weight percent of conductive agent and 2 to 8 weight percent of binder.
According to an embodiment of the present application, the positive electrode sheet may be prepared according to a conventional method in the art. The positive electrode active material, an optional conductive agent, and a binder are generally dispersed in a solvent (e.g., NMP) to form a uniform positive electrode slurry, and the positive electrode slurry is coated on a current collector and dried to obtain a positive electrode sheet.
< separation Membrane >
The separator in the mixed lithium-sodium ion battery of the present application is not particularly limited, and may be any of the techniques disclosed in the prior art. The separator used is not particularly limited in material and shape, and any known porous membrane, composite membrane or nonwoven fabric having electrochemical stability and chemical stability may be used, and the separator material may be selected from a single-layer or multi-layer film of one or more of polyethylene, polypropylene, polyethylene terephthalate, polyimide, glass fiber, polyvinylidene fluoride. Specifically, a polypropylene porous membrane, a polyethylene porous membrane, a polypropylene nonwoven fabric, a polyethylene nonwoven fabric or a polypropylene-polyethylene-polypropylene porous composite membrane can be selected. The substrate layer may be one or more layers, and when the substrate layer is a plurality of layers, the compositions of the polymers of different substrate layers may be the same or different, and the weight average molecular weights of the polymers of different substrate layers are not completely the same; when the substrate layer is a multilayer, the polymers of different substrate layers differ in closed cell temperature.
In some embodiments, the substrate layer has a coating layer disposed on at least one surface thereof, which may be a polymer layer or an inorganic layer, or a layer formed by mixing a polymer with an inorganic material.
The polymer layer contains a polymer, and the material of the polymer comprises at least one of polyamide, polyacrylonitrile, acrylic polymer, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinyl ether, polyvinylidene fluoride or poly (vinylidene fluoride-hexafluoropropylene).
The inorganic layer comprises inorganic particles and a binder, wherein the inorganic particles are selected from one or a combination of a plurality of aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, hafnium oxide, tin oxide, cerium oxide, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, barium sulfate and solid electrolyte. The binder is selected from one or more of polyvinylidene fluoride, copolymer of vinylidene fluoride-hexafluoropropylene, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene and polyhexafluoropropylene.
The present application will be described in further detail with reference to specific examples. It is to be understood that the following examples are illustrative only and are not to be construed as limiting the scope of the application. All techniques implemented based on the above description of the application are intended to be included within the scope of the application.
The experimental methods used in the following examples are all conventional methods unless otherwise specified; the reagents, materials, etc. used in the examples described below are commercially available unless otherwise specified.
For simplicity, only a few numerical ranges are explicitly disclosed. However, any lower limit may be combined with any upper limit to form a range not explicitly recited; and any lower limit may be combined with any other lower limit to form a range not explicitly recited, and any upper limit may be combined with any other upper limit to form a range not explicitly recited. Furthermore, each point or individual value between the endpoints of the range is included within the range, although not explicitly recited. Thus, each point or individual value may be combined as a lower or upper limit on itself with any other point or individual value or with other lower or upper limit to form a range that is not explicitly recited.
In the description herein, unless otherwise indicated, "above" and "below" are intended to include the present number, and the meaning of "multiple" in "one or more" is two or more.
This summary of the application is not intended to describe each disclosed embodiment or every implementation of the present application. The following description more particularly exemplifies illustrative embodiments. Guidance is provided throughout this application by a series of embodiments, which may be used in various combinations. In the various examples, the list is merely a representative group and should not be construed as exhaustive.
The electrical performance test method of the battery in the following examples:
first circle coulombic efficiency: the mixed lithium-sodium ion battery is charged to an upper limit voltage (4.3V) at a constant current of 0.5C at 25 ℃, then charged to a current of 0.05C at a constant voltage of 4.3V, and kept stand for 5 minutes; then discharging to 2.0V with 0.5C constant current, recording the discharge capacity, namely the first-circle discharge capacity, and the first-circle coulomb efficiency is the ratio of the first-circle discharge capacity to the charge capacity.
Normal temperature cycle life: the mixed lithium-sodium ion battery is charged to an upper limit voltage (4.3V) at a constant current of 0.5C at 25 ℃, then charged to a current of 0.05C at a constant voltage of 4.3V, and kept stand for 5 minutes; then, the mixture was discharged at a constant current of 0.5C to a voltage of 2.0V and allowed to stand for 5 minutes, which was a charge-discharge cycle. The charge/discharge is carried out in this way, and the ratio of the discharge capacity after the 100 th cycle to the discharge capacity of the first cycle is recorded, namely the capacity retention rate of 100 circles at normal temperature.
Low temperature cycle life: placing the mixed lithium-sodium ion battery in an incubator at the temperature of minus 20 ℃, charging to the upper limit voltage (4.3V) with a constant current of 0.5C, then charging to the current of 0.05C with a constant voltage of 4.3V, and standing for 5 minutes; then, the mixture was discharged at a constant current of 0.5C to a voltage of 2.0V and allowed to stand for 5 minutes, which was a charge-discharge cycle. The ratio of the discharge capacity after the 100 th cycle to the first cycle discharge capacity is recorded as the capacity retention rate of 100 cycles at low temperature.
Example 1
(1) Preparation of positive plate
The positive electrode active material Prussian blue type material (Na 2 Mn[Fe(CN) 6 ]) Dispersing conductive agent carbon black and binder polyvinylidene fluoride (PVDF) in a proper amount of N-methyl pyrrolidone (NMP) according to a weight ratio of 92:4:4, fully stirring to form uniform positive electrode slurry, coating the positive electrode slurry on a positive electrode current collector aluminum foil, and then drying, rolling and cutting to obtain the positive electrode plate.
(2) Preparation of negative plate
Weighing a negative electrode active material (hard carbon obtained after pyrolyzing phenolic resin at 1200 ℃), conductive agent carbon black, binder styrene-butadiene rubber (SBR) and thickener sodium carboxymethyl cellulose (CMC) according to a weight ratio of 92:1.5:4.5:2, dispersing the materials in a proper amount of deionized water, fully stirring the materials to form uniform negative electrode slurry, coating the negative electrode slurry on a negative electrode current collector copper foil, and then drying, rolling and cutting the negative electrode slurry to obtain a negative electrode plate.
(3) Preparation of separator
A7-mu m wet polyethylene diaphragm is selected as a base material, an alumina ceramic coating with the thickness of 2 mu m is coated on one surface of the base material, PVDF-HFP adhesive layers with the thickness of 1 mu m are respectively coated on two sides of the diaphragm, and the diaphragm with the total thickness of 11 mu m is obtained and is cut into required widths for standby.
(4) Electrolyte preparation
At the water content<In a glove box filled with argon gas at a mass ratio of 1.0:2.0:0.5, ethylene Carbonate (EC), propylene Carbonate (PC) and ethylene glycol dimethyl ether (DME) were mixed, and 1.0mol/L lithium hexafluorophosphate (LiPF) was added thereto 6 ) And 1.0mol/L sodium hexafluorophosphate (NaPF) 6 ) And stirring uniformly to obtain the electrolyte for the mixed lithium-sodium ion battery.
(5) Preparation of mixed lithium-sodium ion battery
And sequentially stacking the positive electrode, the diaphragm and the negative electrode, enabling the isolating film to be positioned between the positive electrode and the negative electrode, welding the electrode lugs and winding to obtain a winding core, placing the winding core in an aluminum plastic film packaging bag, finally injecting the electrolyte, and performing the procedures of vacuum sealing, standing, formation, shaping and the like to obtain the mixed lithium-sodium ion battery.
Examples 2 to 16
A hybrid lithium-sodium ion battery was prepared according to the method in example 1, except that: the types and the addition amounts of the solvents used in the preparation process of the electrolyte are different, and specific information is shown in tables 1 and 2.
Comparative examples 1 to 8
A hybrid lithium-sodium ion battery was prepared according to the method in example 1, except that: the types and the addition amounts of the solvents used in the preparation process of the electrolyte are different, and specific information thereof is shown in tables 1 and 2.
TABLE 1 types and amounts of solvents used in the different examples and their corresponding electrochemical properties
TABLE 2 types and amounts of solvents used in the different examples and their corresponding electrochemical properties
From the results shown in tables 1 and 2, propylene Carbonate (PC) has better low-temperature performance in the electrolyte, but the pure PC solvent has larger viscosity, which is unfavorable for the preparation of high conductivity, so that the ionic conductivity of the electrolyte is further improved by selecting the ether compound with low viscosity, and the ether electrolyte is favorable for promoting the formation of stable SEI film and improving the cycle stability of the battery. Therefore, the PC-based and ether-based mixed electrolyte used in the mixed lithium-sodium ion battery can effectively improve the low-temperature performance and the cycle stability of the battery.
The embodiments of the present application have been described above. However, the present application is not limited to the above embodiment. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims (10)

1. An electrolyte is characterized by comprising a composite organic solvent, lithium salt and sodium salt; the composite organic solvent comprises propylene carbonate and an ether compound, wherein the mass of the propylene carbonate accounts for 10-80 wt% of the total mass of the composite organic solvent, and the mass of the ether compound accounts for 5-40 wt% of the total mass of the composite organic solvent.
2. The electrolyte according to claim 1, wherein the mass of the propylene carbonate is 20 to 80wt% of the total mass of the composite organic solvent;
and/or the mass of the ether compound accounts for 10-30wt% of the total mass of the composite organic solvent.
3. The electrolyte according to claim 1, wherein the ether compound is selected from one or more of ethylene glycol dimethyl ether (DME), diethylene glycol dimethyl ether (DEGDME), triethylene glycol dimethyl ether (TRGDME), tetraethylene glycol dimethyl ether (TEGDME), fluoroether (F-EPE), fluoroether (D2), fluoroether (HFPM), fluoroether (MFE), fluoroether (EME), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), 1, 3-Dioxane (DOL), and 1, 4-Dioxane (DOX) in any ratio.
4. The electrolyte of claim 1, wherein the composite organic solvent further comprises other solvents selected from one or more of Ethylene Carbonate (EC), butylene carbonate, difluoroethylene carbonate (DFEC), fluorodimethyl carbonate, fluoroethyl methyl carbonate, dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate, ethyl Methyl Carbonate (EMC), methyl formate, ethyl formate, propyl formate, butyl formate, methyl acetate, ethyl Acetate (EA), propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, methyl difluoroacetate, ethyl difluoroacetate, γ -butyrolactone (GBL), γ -valerolactone, δ -valerolactone, sulfolane, dimethyl sulfoxide (DMSO), methylene chloride, dichloroethane, in any ratio.
5. The electrolyte according to claim 1, wherein the concentration of lithium salt in the electrolyte is 0.2 to 5.0mol/L;
and/or, the concentration of sodium salt in the electrolyte is 0.2-5.0 mol/L.
6. The electrolyte of claim 1, further comprising an additive selected from one or more of Vinylene Carbonate (VC), vinylene carbonate (VEC), 1, 3-propane sultone, trifluoromethylcarbonate, dimethyl sulfate, vinyl methyl sulfate, propylene sulfate, ethylene sulfite, succinic anhydride, biphenyl, diphenyl ether, toluene, xylene, cyclohexylbenzene, fluorobenzene, p-fluorotoluene, p-fluoroanisole, t-butylbenzene, t-pentylbenzene, propenolactone, butane sultone, methane disulfonic acid methylene ester, ethylene glycol bis (propionitrile) ether, hexamethyldisilazane, heptamethyldisilazane, dimethyl methylphosphonate, diethyl ethylphosphonate, trimethyl phosphate, triethyl phosphate, triphenyl phosphite, tris (trimethylsilyl) borate, tris (trimethylsilyl) phosphate, and the like, in any ratio.
7. A hybrid lithium sodium ion battery comprising the electrolyte of any one of claims 1-6.
8. The hybrid lithium-sodium ion battery of claim 7, further comprising a negative electrode sheet comprising a negative electrode active material selected from the group consisting of natural graphite, artificial graphite, mesophase micro-carbon spheres, hard carbon, soft carbon, sn, snO, snO 2 、Sb、Sb 2 O 3 、Bi、Bi 2 O 3 And TiO 2 One or more of the following.
9. The hybrid lithium-sodium ion battery of claim 7, further comprising a positive electrode sheet comprising a positive electrode active material comprising one or more of a transition metal layered oxide, a polyanionic material, and a prussian blue-based material.
10. The hybrid lithium-sodium ion battery of claim 9, wherein the battery comprises a plurality of lithium-sodium batteries,
the Prussian blue material has a chemical formula A x M z [Fe(CN) 6 ] y Wherein A is an alkali metal cation, M is a transition metal cation, x is more than or equal to 1 and less than or equal to 2,0.9, y is more than or equal to 1,0.8 and z is more than or equal to 1;
and/or the chemical formula of the polyanionic material is A' x’ M’ y’ (X n’ O m ) z’ F w Wherein A 'is Li and/or Na, M' is a transition metal ion of variable valence, X is one or more of P, S and Si, and X 'is not less than 1, y'>The values of 0, z 'is more than or equal to 1, w is more than or equal to 0, and n' and m accord with the principle of conservation of charge.
CN202210200220.3A 2022-03-02 2022-03-02 Electrolyte and mixed lithium-sodium ion battery comprising same Pending CN116742134A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210200220.3A CN116742134A (en) 2022-03-02 2022-03-02 Electrolyte and mixed lithium-sodium ion battery comprising same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210200220.3A CN116742134A (en) 2022-03-02 2022-03-02 Electrolyte and mixed lithium-sodium ion battery comprising same

Publications (1)

Publication Number Publication Date
CN116742134A true CN116742134A (en) 2023-09-12

Family

ID=87899919

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210200220.3A Pending CN116742134A (en) 2022-03-02 2022-03-02 Electrolyte and mixed lithium-sodium ion battery comprising same

Country Status (1)

Country Link
CN (1) CN116742134A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117691191A (en) * 2024-01-31 2024-03-12 南京理工大学 Non-inflammable and high-voltage-resistant sultone-based lithium battery and electrolyte

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117691191A (en) * 2024-01-31 2024-03-12 南京理工大学 Non-inflammable and high-voltage-resistant sultone-based lithium battery and electrolyte
CN117691191B (en) * 2024-01-31 2024-04-16 南京理工大学 Non-inflammable and high-voltage-resistant sultone-based lithium battery and electrolyte

Similar Documents

Publication Publication Date Title
CN100481609C (en) A super capacitance cell
CN111540945B (en) Electrolyte and electrochemical device
US11145852B2 (en) Anode active material and anode using same, electrochemical device and electronic device
CN110112465B (en) Electrolyte for battery with lithium-rich manganese-based positive electrode material system and lithium ion battery
CN110994018B (en) Electrolyte and electrochemical device
CN111342137B (en) Electrolyte and electrochemical device
CN111342129B (en) Electrolyte and electrochemical device
CN112400249A (en) Electrolyte and electrochemical device
CN113906606A (en) Electrolyte solution, electrochemical device, and electronic device
WO2021223181A1 (en) Electrolyte and electrochemical device
CN111697267A (en) Electrolyte solution, electrochemical device containing electrolyte solution, and electronic device
CN112103561B (en) Electrolyte and electrochemical device
JP7311593B2 (en) Electrolyte and electrochemical device
CN116742134A (en) Electrolyte and mixed lithium-sodium ion battery comprising same
CN111971845A (en) Electrolyte and electrochemical device
CN116742133A (en) Electrolyte and mixed lithium-sodium ion battery comprising same
CN114400375A (en) Electrolyte solution, electrochemical device, and electronic device
CN114156537A (en) Electrolyte and electrochemical device comprising same
CN114221034A (en) Electrochemical device and electronic device comprising same
CN112368872A (en) Electrolyte and electrochemical device
CN116741945A (en) Positive electrode active material, positive electrode plate comprising same and mixed lithium sodium ion battery
CN116741978A (en) Negative electrode active material, negative electrode plate and mixed lithium-sodium ion battery
CN114583177B (en) Electrochemical device and electronic device comprising the same
WO2022193122A1 (en) Lithium replenishment additive, electrochemical apparatus comprising same, and electronic device
CN116741939A (en) Negative plate and mixed lithium-sodium ion battery

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination