CN111211303B - Negative electrode active material and preparation method and application thereof - Google Patents
Negative electrode active material and preparation method and application thereof Download PDFInfo
- Publication number
- CN111211303B CN111211303B CN202010031172.0A CN202010031172A CN111211303B CN 111211303 B CN111211303 B CN 111211303B CN 202010031172 A CN202010031172 A CN 202010031172A CN 111211303 B CN111211303 B CN 111211303B
- Authority
- CN
- China
- Prior art keywords
- lithium
- graphite
- active material
- negative electrode
- rich anti
- 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.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/366—Composites as layered products
-
- 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
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
- H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/027—Negative electrodes
-
- 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 invention provides a negative active material and a preparation method and application thereof, wherein the negative active material comprises a graphite intercalation compound and a coating layer for coating graphite in the graphite intercalation compound; wherein the intercalation agent in the graphite intercalation compound and the material of the coating layer comprise a lithium-rich anti-perovskite material Li3OX, X are selected from at least one halogen atom. The negative active material can accelerate the transmission speed of lithium ions, improve the diffusion capacity of the lithium ions, and is beneficial to improving the cycle performance and the quick charge performance of the lithium ion battery.
Description
Technical Field
The invention relates to a negative electrode active material, in particular to a negative electrode active material, a preparation method and application thereof, and belongs to the technical field of batteries.
Background
At the present stage, no matter in the 3C consumption field or the new power energy field, the fast-charging lithium ion battery gradually becomes the mainstream, and particularly for the power lithium ion battery, while pursuing one-time endurance mileage, also pursuing large-current fast-charging to indirectly improve the endurance mileage.
However, since the graphite negative electrode of the lithium ion battery has an orderly stacked layered structure, the speed of lithium ions being intercalated into the graphite is limited during large-current charging, so that the polarization of the graphite negative electrode is increased, the lithium potential is reduced, and even the risk of short-circuit ignition of the battery caused by lithium precipitation of the graphite negative electrode exists. In addition, the quick charging current is too large, the graphite negative electrode polarization is large, the DCIR value is large, the heat production quantity is large, the temperature is increased, the phenomena that the service life of the battery is shortened due to excessive consumption of electrolyte, the battery is short-circuited due to contraction of a diaphragm, and tab glue drops and leaks when the temperature of the positive electrode aluminum tab is too high can occur.
Therefore, the embedding speed of lithium ions during fast charging is improved, the DCIR of the graphite cathode is reduced, and polarization is reduced, so that the method has very important significance for improving the fast charging and low temperature performance of the lithium ion battery, improving the cycle performance and prolonging the service life of the lithium ion battery.
Disclosure of Invention
The invention provides a negative electrode active material which can accelerate the transmission speed of lithium ions, improve the diffusion capacity of the lithium ions and is beneficial to improving the cycle performance and the quick charge performance of a lithium ion battery.
The invention provides a preparation method of a negative electrode active material, which has strong practicability and can modify a graphite negative electrode in a high-efficiency and large-scale manner to prepare the negative electrode active material for accelerating the lithium ion transmission speed and improving the lithium ion diffusion capacity.
The invention also provides a negative plate which comprises the negative active material, can accelerate the transmission speed of lithium ions, improves the diffusion capacity of the lithium ions, and is beneficial to improving the cycle performance and the quick charge performance of the lithium ion battery.
The invention also provides a lithium ion battery, and the negative electrode of the lithium ion battery is the negative plate.
The invention provides a negative active material, which comprises a graphite intercalation compound and a coating layer for coating graphite in the graphite intercalation compound;
wherein the intercalation agent in the graphite intercalation compound and the material of the coating layer comprise a lithium-rich anti-perovskite material Li3OX, X are selected from at least one halogen atom.
The negative active material as described above, wherein the lithium-rich anti-perovskite material in the intercalation agent and the coating layer is the same.
The negative electrode active material as described above, wherein, in the negative electrode active material, the lithium-rich anti-perovskite material Li3Of OX with graphiteThe mass ratio is (0.005-0.1): 1.
the negative electrode active material as described above, wherein graphite is mixed with the lithium-rich anti-perovskite material Li3And (3) after OX is mixed and ground, the temperature is kept at 282-400 ℃, and the anode active material is obtained after cooling.
The invention also provides a preparation method of the anode active material, which comprises the following steps:
1) graphite and lithium-rich anti-perovskite material Li3OX is mixed and ground to obtain a mixture;
2) and heating the mixture to 282-400 ℃, preserving the heat and cooling to obtain the negative electrode active material.
The preparation method of the anode active material, wherein in the step 1), the lithium-rich anti-perovskite material Li3The mass ratio of OX to the graphite is (0.005-0.1): 1.
the preparation method of the anode active material is characterized in that in the step 2), the heat preservation time is controlled to be not less than 1 h.
The method for preparing the anode active material as described above, wherein, in the step 2), the cooling includes: the temperature of the system is reduced to room temperature within 1-5 min.
The invention also provides a negative electrode sheet comprising the negative electrode active material.
The invention also provides a lithium ion battery, and the negative electrode of the lithium ion battery is the negative plate.
The negative active material of the invention is a lithium-rich anti-perovskite material Li3OX intercalated and coated graphite intercalation compound, the lithium-rich anti-perovskite material Li3The intercalation treatment of OX on the graphite not only enlarges the graphite interlayer spacing to improve the transmission speed of lithium ions, but also improves the diffusion capacity of the lithium ions by forming an SEI film on the graphite surface, so that when a lithium ion battery comprising the negative active material is charged with large current, the negative plate can not generate the negative electrochemical polarization phenomenon due to the limitation of the lithium ion intercalation speed, the large current quick charge can be realized more safely, and the requirement of the endurance mileage can be met;after the embedding speed of the lithium ions is optimized, the DCIR value during large-current quick charging can be obviously reduced, so that the consumption of the electrolyte due to overhigh temperature is avoided, and the cycle performance and the cycle life of the lithium ion battery are further optimized;
in addition, the lithium-rich anti-perovskite material Li in the invention3The oxidation-reduction potential of OX is higher than that of graphite, so that the generation of lithium dendrite caused by polarization under high-current charging and low-temperature charging can be avoided, and the safety performance of the battery is improved.
Drawings
Fig. 1 is a schematic structural view of a negative active material according to the present invention;
FIG. 2 is a discharge curve of a lithium ion battery C1-C6 according to the present invention cycling at 0 ℃ for 1 cycle;
FIG. 3 is a graph of capacity retention for 10 cycles of the lithium ion battery of the present invention at 0 ℃ C. 1-C6;
FIG. 4 is a graph of capacity retention of the lithium ion battery C1-C6 at 25 ℃ under 3C/1C fast charging.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention and the accompanying drawings. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Fig. 1 is a schematic structural view of a negative active material according to the present invention, and as shown in fig. 1, the negative active material according to the present invention includes a graphite intercalation compound and a coating layer 1 coating graphite in the graphite intercalation compound;
wherein the intercalation agent in the graphite intercalation compound and the material of the coating layer 1 comprise a lithium-rich anti-perovskite material Li3OX, X are selected from at least one halogen atom.
The graphite intercalation compound of the invention is graphite with an intercalation layer 3 after intercalation treatment of graphite 2, and the coating layer 1 is a functional layer which completely coats the graphite surface in the graphite intercalation compound.
In particular, the invention adopts a lithium-rich anti-perovskite material Li3OX serves as a graphite intercalation agent and a coated material. The lithium-rich anti-perovskite material Li of the invention3OX is a low melting point (around 282 deg.C) with acceptable lithium ion conductivity (10. about.-5Scm-1) And a solid electrolyte chemically stable to lithium metal. In one embodiment, the lithium-rich anti-perovskite material Li of the present invention for the intercalant and the cladding layer3OX can be independently selected from Li3OF、Li3OCl、Li3OBr、Li3OI、Li3OAxBy(A, B is selected from one of F, Cl, Br and I, and x + y is 1) or a combination thereof.
When the negative active material is used as the active material of the negative plate of the lithium ion battery, the high-current quick charge of the lithium ion battery can be safely realized, and the low-temperature cycle performance, the room-temperature cycle performance and the cycle life of the lithium ion battery can be optimized. The inventors analyzed the anode active material based on this phenomenon, and considered that it is possible to: since the two-dimensional layered structure of pure graphite is tightly bound together by weak van der waals force with an interlayer distance of 0.3345nm, when a lithium ion battery including a pure graphite negative electrode is charged and discharged, lithium ions are deintercalated between graphite layers, and the above cycle is repeated. However, due to the ordered arrangement among graphite layers and the narrowness of interlayer spacing, the low-temperature battery has poor dynamic performance, the transmission of lithium ions on the graphite surface and among the graphite layers is blocked during high-rate charging, the diffusion between the graphite surface and the inside is blocked, the polarization is large, the direct-current internal resistance is high, the risk of lithium precipitation is increased, the electrolyte consumption is increased, and the phenomenon of cyclic water jump is caused. The negative active material of the invention is prepared by a lithium-rich anti-perovskite material Li3The intercalation and coating of OX on the graphite not only increases the interlayer spacing of the graphite and enlarges the transmission channel of lithium ions between graphite layers, but also increases the lithium-rich anti-perovskite material Li between the graphite layers3OX and surface-coated lithium-rich anti-perovskite material Li3OX is connectedAnd then, a terrace-type lithium ion transmission channel is formed, so that the transmission area of lithium ions is increased, the diffusion speed on the surface and inside of graphite is increased, and the narrow single interlayer transmission of pure graphite is avoided, thereby improving the cycle performance and the quick charge performance of the lithium ion battery.
In the specific implementation process, the lithium-rich anti-perovskite material of the intercalation agent can be the same as the lithium-rich anti-perovskite material of the coating layer, which is beneficial to realizing the efficient connection between the lithium-rich anti-perovskite material between graphite layers and the lithium-rich anti-perovskite material coated on the surface, thereby further accelerating the transmission speed of lithium ions.
The negative active material of the invention can be prepared by graphite and a lithium-rich anti-perovskite material Li3OX is prepared, wherein, the lithium-rich anti-perovskite material Li3The mass ratio of OX to graphite is (0.005-0.1): 1.
specifically, graphite and a lithium-rich anti-perovskite material Li are mixed3And (4) after OX is mixed and ground, the temperature is kept at 282-400 ℃, and the anode active material is obtained after cooling.
The graphite may be selected from one of natural graphite, artificial graphite and mesocarbon microbeads, and further has a particle size of 30-100 μm.
In particular, during milling, graphite and Li, a lithium-rich anti-perovskite material, can be treated in a glove box (both moisture and oxygen content below 0.5ppm)3Grinding OX, generally, for at least 1 h; or a ball mill (strictly sealed) is used for mixing graphite and the lithium-rich anti-perovskite material Li3Performing dry ball milling or wet ball milling on OX, wherein the ball milling time of the dry ball milling or wet ball milling is 2-24h, and the ball milling rotation speed is 200-3A mixture of OX and ball mill solvent) is 30-70% by mass.
After the grinding is finished, the ground system is heated to 282-400 ℃ for melting treatment, in order to ensure the Li-rich anti-perovskite material Li3Melting of OX can be carried out by holding the temperature for at least 1h, e.g. 1-48h, after warming, followed by cooling to room temperature(25-30 ℃) to obtain the active negative electrode material of the invention. The invention is not limited to the specific apparatus for heating, and can be a crucible or a stainless steel reaction kettle, for example.
In the preparation process, the cooling speed can be further controlled to further improve the transmission speed of lithium ions, and specifically, the heat preservation system can be cooled to room temperature within 1-5min by using a cooling mode such as liquid nitrogen.
The negative active material comprises a graphite intercalation compound and a coating layer for coating the graphite intercalation compound, wherein the intercalation material and the coating layer in the graphite intercalation compound comprise a lithium-rich anti-perovskite material Li3OX, X are selected from at least one halogen atom. Compared with the traditional pure graphite cathode active material, the cathode active material greatly increases the transmission area of lithium ions on the surface and between layers of graphite, reduces the polarization of a lithium ion battery using the cathode active material during low-temperature and high-rate charge and discharge, and effectively improves the cycle performance of the low-temperature and fast-charging battery; in addition, Li is taken as the lithium-rich anti-perovskite material3The oxidation-reduction potential of OX is higher than that of graphite, so that the risk of lithium precipitation during low-temperature and high-rate charging can be reduced, and the safety of the lithium ion battery is greatly improved.
The invention also provides a preparation method of the anode active material, which comprises the following steps:
1) graphite and lithium-rich anti-perovskite material Li3OX is mixed and ground to obtain a mixture;
2) heating the mixture to 282-400 ℃, preserving the heat and cooling to obtain the cathode active material.
In the step 1), the graphite can be selected from one of natural graphite, artificial graphite and mesocarbon microbeads, and the particle size can be 30-100 μm; lithium-rich anti-perovskite material Li3OX can be selected from Li3OF、Li3OCl、Li3OBr、Li3OI、Li3OAxBy(A, B is selected from one of F, Cl, Br and I, and x + y is 1) or a combination thereof.
In particular in grindingIn the process, graphite and Li-rich anti-perovskite material Li can be treated in a glove box (the moisture and oxygen content are both lower than 0.5ppm)3Grinding OX, generally, for at least 1 h; or a ball mill is used for mixing graphite and the lithium-rich anti-perovskite material Li3Performing dry ball milling or wet ball milling on OX, wherein the ball milling time of the dry ball milling or wet ball milling is 2-24h, and the ball milling rotation speed is 200-3A mixture of OX and ball mill solvent) is 30-70% by mass.
After the grinding is completed, the particle size of the graphite is generally 1 to 20 μm.
After the grinding is finished, heating the ground mixture to 282-400 ℃ and preserving the temperature for a period of time to ensure that the lithium-rich anti-perovskite material Li3OX is melted and then cooled down to room temperature (25-30 ℃ C.) to obtain the active anode material of the invention. The invention is not limited to the specific apparatus for heating, and can be a crucible or a stainless steel reaction kettle, for example.
Wherein, the heat preservation time can be controlled to be not less than 1h, for example, 1-48 h.
Further, in step 2), the cooling rate may be further controlled to further increase the transmission rate of lithium ions, and specifically, the temperature of the thermal insulation system may be reduced to room temperature within 1-5min by using a cooling method such as liquid nitrogen. The inventors surmised that rapid cooling might bring the graphite in the negative active material to an amorphous state, thereby contributing to an increase in the transport speed of lithium ions.
In addition, graphite and lithium-rich anti-perovskite material Li can be controlled3The mass ratio of OX further optimizes the performance of the anode active material.
In the practice of the invention, the lithium-rich anti-perovskite material Li is generally controlled3The mass ratio of OX to graphite is more than 0.01%. Reasonably controlling lithium-rich anti-perovskite material Li3The mass ratio of OX to graphite is favorable for further improving the quick charge performance and the cycle performance of the lithium ion battery comprising the negative active material, so that the lithium-rich anti-perovskiteMaterial Li3The mass ratio of OX and graphite is controlled to be more than 0.5%. The inventor researches and discovers that Li is taken as a lithium-rich anti-perovskite material3The mass ratio of OX to graphite is increased within a certain range, the quick charge performance and the cycle performance of the lithium ion battery are gradually improved and then show a descending trend, so that the lithium-rich anti-perovskite material Li is generally considered from the consideration of performance optimization and preparation economy3The mass ratio of OX to graphite is controlled to 0.5-10%, and further 0.5-5%.
The invention adopts the melted lithium-rich anti-perovskite material Li3OX carries out intercalation treatment and coating treatment on the graphite, thereby obtaining the lithium-rich anti-perovskite material Li3Preparation of Li by taking OX as intercalation agent of graphite and negative active material pole of SEI film3OX intercalates the graphite so that the lithium-rich anti-perovskite material Li3SEI film of OX and lithium-rich anti-perovskite material Li capable of greatly enlarging graphite interlayer spacing3OX forms a perfect 'terrace-shaped' lithium ion channel on graphite cathode particles from inside to outside, and lithium-rich anti-perovskite material Li coated between graphite layers and on the surface3OX is used as ridges of the terrace, graphite is used as ridges of the terrace, lithium ions are transmitted along the ridges, and electrons are transmitted along the ridges, so that the lithium ion transmission rate and the electron transmission rate can be greatly improved, the electrochemical polarization of the negative electrode can be reduced to the greatest extent, the DCIR value is reduced, the low-temperature performance and the quick-charging performance of the lithium ion battery comprising the negative electrode active material are improved, the temperature rise is reduced, the consumption of electrolyte is reduced, and the cycle life of the lithium ion battery is prolonged.
The invention also provides a negative electrode sheet, which comprises the negative electrode active material.
Specifically, during operation, a negative electrode active material, a binder and a conductive agent are dispersed in a proper amount of solvent, and are fully stirred and mixed to form uniform negative electrode slurry; and uniformly coating the negative electrode slurry on a copper foil of a negative current collector, and drying, rolling and slitting to obtain a negative plate.
The binder, the conductive agent and the solvent are not limited in the present invention, and may be materials commonly used in lithium ion batteries.
The negative plate of the invention comprises the lithium-rich anti-perovskite material Li3OX intercalation agent and lithium-rich anti-perovskite material Li3The anode active material of the OX SEI film, so that the graphite in the anode sheet not only increases the interlayer spacing and enlarges the transmission channel of lithium ions between graphite layers, but also increases the lithium-rich anti-perovskite material Li between the graphite layers3OX intercalation agent and surface-coated lithium-rich anti-perovskite material Li3The OX SEI films are connected to form a terrace-type lithium ion transmission channel, so that the transmission area of lithium ions is increased, the diffusion speed between the surface of graphite and the inner part of the graphite is increased, the narrow single interlayer transmission of pure graphite is avoided, and the quick charge performance and the cycle performance of the lithium ion battery comprising the negative plate are favorably improved.
The invention also provides a lithium ion battery, and the negative electrode of the lithium ion battery is the negative plate.
The lithium ion battery of the present invention may further include a positive electrode sheet, an electrolyte, and a separator, in addition to the negative electrode sheet.
The active material of the positive plate is not strictly limited, and can be a positive active material commonly used in the current lithium ion battery, such as at least one of lithium cobaltate, lithium nickelate, lithium manganate, nickel cobalt manganese ternary material, nickel cobalt aluminum ternary material, lithium iron phosphate (LFP), lithium nickel manganate, lithium-rich manganese-based material, and the like.
Specifically, in the operation, the at least one positive electrode active material, the conductive agent and the binder may be dispersed in an appropriate amount of solvent, and fully stirred and mixed to form a uniform positive electrode slurry; and uniformly coating the positive slurry on a positive current collector aluminum foil, and drying, rolling and slitting to obtain the positive plate.
The electrolyte is not strictly limited, and may include one or more of the solvents commonly used in the current lithium ion battery electrolyte, and the electrolyte lithium salt commonly used in the current lithium ion electrolyte, such as: the solvent may be ethylene carbonate, propylene carbonate, butylene carbonate, fluoroethylene carbonate (FEC), dimethyl carbonate (DMC), diethyl carbonate (DEC), difluoroethylene carbonate (DFEC),Dipropyl carbonate, Ethyl Methyl Carbonate (EMC), ethyl acetate, ethyl propionate, propyl acetate, propyl propionate, sulfolane, γ -butyrolactone, etc.; the lithium salt is selected from lithium hexafluorophosphate (LiPF)6) One or more of lithium bis (fluorosulfonyl) imide (LiFSI), lithium bis (trifluoromethylsulfonyl) imide (LiTFSI).
The material selection of the diaphragm is not strictly limited, and the diaphragm can be a diaphragm material commonly used in the current lithium ion battery, such as one of a polypropylene diaphragm (PP), a polyethylene diaphragm (PE), a polypropylene/polyethylene double-layer composite membrane (PP/PE), a polyimide electrostatic spinning diaphragm (PI), a polypropylene/polyethylene/polypropylene three-layer composite membrane (PP/PE/PP), a cellulose non-woven fabric diaphragm and a diaphragm with a ceramic coating.
When the lithium ion battery is prepared, the positive plate, the diaphragm and the negative plate are wound or laminated to obtain a bare cell, and the bare cell is packaged into an aluminum-plastic film bag which is formed in a stamping mode in advance. And after the packaged battery is dried at 85 ℃, injecting the electrolyte into the dried battery, and after the battery is laid aside, formed and sealed for the second time, finishing the preparation of the lithium ion battery.
The lithium ion battery provided by the invention has excellent cycle performance and quick charge performance due to the inclusion of the negative plate.
Hereinafter, the anode active material and the preparation method of the present invention will be described in detail by way of specific examples.
Example 1
The method for preparing the anode active material of the present embodiment includes the steps of:
adding Li into the lithium-rich anti-perovskite material3OCl and 20 μm diameter graphite powder (Li-rich anti-perovskite material3The mass ratio of OX to graphite powder is 0.01: 1) the mixture was ground in a glove box (moisture and oxygen contents were less than 0.5ppm) for 1 hour, and the ground mixture was placed in a stainless steel reaction vessel, heated to 350 ℃ and kept warm for 24 hours, and then rapidly cooled (cooled to 25 ℃ in 5 min), thereby obtaining negative electrode active material G1 of this example.
Example 2
Preparation of negative electrode active Material G2 of the present exampleThe preparation method is basically the same as that of the embodiment 1, and the only difference is that the lithium-rich anti-perovskite material Li in the embodiment3The mass ratio of OCl to graphite powder is 0.02: 1.
example 3
The preparation method of the negative electrode active material G3 in this example was substantially the same as that in example 1, except that Li was used as the lithium-rich anti-perovskite material in this example3OBr, and Li3The mass ratio of the OBr to the graphite powder is 0.05: 1.
example 4
The preparation method of the negative electrode active material G4 of this example was substantially the same as that of example 1, except that the lithium-rich anti-perovskite material Li in this example was used3The mass ratio of OCl to graphite powder is 0.1: 1.
example 5
The preparation method of the negative electrode active material G5 of this example was substantially the same as that of example 1, except that the lithium-rich anti-perovskite material Li in this example was used3The mass ratio of OCl to graphite powder is 0.2: 1.
test examples
After the negative electrode active materials G1-G5 of examples 1-3 were prepared into negative electrode sheets N1-N3, respectively, the positive electrode sheets P were matched with each other to form bare cells by Z-type lamination, and aluminum tabs and copper nickel-plated tabs were rolled out. Clamping the bare cell by a glass clamp with a force of 100MPa/m2And vacuum baking at 85 deg.C for 24 hr, and packaging with aluminum plastic film. The above process is carried out at humidity<And 5% of environment. The electrolyte is 1M lithium hexafluorophosphate electrolyte, and the solvent is a mixed solvent of ethylene carbonate/dimethyl carbonate/1, 2 propylene carbonate (volume ratio is 1:1: 1). After packaging, the battery was subjected to formation and aging to obtain a rectangular flexible packaging battery having a length, width and thickness of 160mm × 60mm × 10mm, and was designated as C1-C5.
Further, a rectangular flexible packaging battery C6 of a comparative example was obtained in the same manner as described above, using the graphite powder in example 1 as a negative electrode active material G6.
The preparation method of the negative plate comprises the following steps: respectively mixing G1-G6 with PVDF binder and conductive carbon black serving as a conductive agent in an environment with the humidity of less than 5%, and uniformly dispersing the mixture by high-speed stirring to prepare a mixture containing a negative active material. In the mixture, the solid component contained 95 wt% of a negative electrode active material (G1-G6, respectively), 1.5 wt% of conductive carbon black Super-P, and 3.5 wt% of a binder. N-methyl pyrrolidone is used as a solvent to prepare cathode active material slurry, and the solid content in the cathode active material slurry is 50 wt%. The negative electrode active material slurry is uniformly coated on two sides of a copper foil, and the negative electrode sheet is obtained by drying and compacting by a roll squeezer, and is marked as N1-N6.
The preparation method of the positive plate comprises the following steps: mixing the ternary nickel-cobalt-manganese NCM serving as the positive electrode active substance, the PVDF serving as the binder and the conductive carbon black, and stirring at a high speed to obtain a uniformly dispersed mixture. In the mixture, the solid component contained 95% by weight of NCM, 2% by weight of PVDF as binder and 3% by weight of conductive carbon black. The mixture was made into positive electrode active material slurry using N-methylpyrrolidone as a solvent, and the solid content in the slurry was 70 wt%. And uniformly coating the slurry on two surfaces of an aluminum foil, drying, and compacting by a roller press to obtain the positive plate P.
1. Interlayer spacing of negative active materials G1-G6
The graphite (002) interplanar spacing d002, i.e., graphite layer spacing, was measured by X-ray diffraction (XRD) using negative active materials G1 to G6 (5 samples per negative active material), and the measurement results are shown in table 1. Wherein the determination conditions are as follows: the Cu rake Kalpha ray source has the target current of 40mA, the voltage of 40KV, the wavelength of 0.15418nm, the scanning range of 10-90 degrees and the scanning speed of 5 degrees/min. Degree (C)
TABLE 1
| G1/nm | G2/nm | G3/nm | G4/nm | G5/nm | G6/ |
|
| 1# | 0.406 | 0.436 | 0.453 | 0.462 | 0.464 | 0.339 |
| 2# | 0.411 | 0.440 | 0.456 | 0.459 | 0.463 | 0.337 |
| 3# | 0.408 | 0.438 | 0.459 | 0.46 | 0.465 | 0.340 |
| 4# | 0.410 | 0.432 | 0.463 | 0.462 | 0.461 | 0.336 |
| 5# | 0.406 | 0.441 | 0.458 | 0.465 | 0.46 | 0.338 |
From table 1, it can be seen that: in the negative active materials of examples 1 to 5, the interlayer spacing of the intercalated graphite was increased and the degree of expansion was increased, as compared with graphite. However, when the content of the lithium-rich anti-perovskite material is increased to a certain proportion, the interlayer spacing of the intercalated graphite is not increased any more, which indicates that the lithium-rich anti-perovskite material has a certain limit on intercalation between graphite layers.
2. DCIR value detection of lithium ion battery C1-C6 at 25 ℃ and-30 DEG C
3 samples of the lithium ion batteries C1-C6 were taken, respectively, and the voltage and current values were measured at 25 ℃ 50% SOC 2.5C discharge for 10s and-30 ℃ 50% SOC 0.25C discharge for 10s, respectively, and the DCIR value was obtained from the ratio of the voltage drop to the current, and the results are shown in Table 2.
TABLE 2
From table 2, it can be seen that:
under normal temperature (25 ℃) or low temperature (-30 ℃), the DCIR value of the lithium ion battery C1-C5 is lower than that of C6, so that the negative active material can reduce polarization in the battery cycle process, and has certain promotion on low-temperature charge and discharge and high-rate charge and discharge.
Particularly, when the mass ratio of the lithium-rich anti-perovskite material to the graphite is below 5%, the DCIR value is significantly higher than that of C6, and it is presumed that when the lithium-rich anti-perovskite material is too much, the lithium-rich anti-perovskite material layer coated on the surface of the graphite is too thick, and the lithium ion transmission is blocked.
3. Low temperature cycle detection at 0 deg.C
The lithium ion battery C1-C6 is subjected to 0 ℃ low-temperature 0.5C/0.5C 100% DOD 10T cycle performance test, the test process is as follows, under the environment of 0 ℃, 0.5C constant current charging is firstly carried out to 4.2V, then constant voltage charging is carried out, the current is cut off to be 0.05C, finally 0.5C constant current discharging is carried out to be 2.5V, the cycle test is carried out for 10 circles, the discharging capacity and the voltage value of the first circle are recorded, and the test result is shown in figure 2.
FIG. 2 is a discharge curve of the lithium ion battery C1-C6 of the present invention cycling at 0 ℃ for 1 cycle.
As can be seen from FIG. 2, the discharge capacity of the lithium ion battery C1-C5 at low temperature of 0 ℃ is better than that of the lithium ion battery C6 at low temperature of 0 ℃, wherein the discharge capacity of the lithium ion battery C1-C3 is 1500mAh greater than that of the lithium ion battery C6 at low temperature of 0 ℃.
FIG. 3 is a graph of capacity retention for 10 cycles of the lithium ion battery of the present invention at 0 ℃ C. 1-C6.
As can be seen from fig. 3, the cycle performance of the lithium ion battery C1-C5 at a low temperature environment of 0 ℃ is better than that of the lithium ion battery C6 at a low temperature environment of 0 ℃, particularly, the capacity retention rate of the lithium ion battery C1-C3 after 10 cycles of low temperature cycle is close to 90%, the capacity retention rate of the lithium ion battery C4 after 10 cycles of low temperature cycle is close to 80%, and the capacity retention rate of the lithium ion battery C6 is lower than 50%.
Therefore, fig. 2 and fig. 3 show that the negative active material of the present invention can reduce polarization of the battery during low-temperature charging, improve low-temperature charging and discharging capacity, reduce the risk of low-temperature lithium precipitation, improve cycle performance and safety performance of the battery in a low-temperature environment, and greatly improve low-temperature performance of the battery.
4. Room temperature cycle detection at 25 deg.C
The battery C1-C6 prepared in the method is subjected to a 3C/1C 100% DOD cycle performance test at room temperature of 25 ℃, the test process is as follows, the 3C constant current charging is firstly carried out until the voltage is 4.2V, then the constant voltage charging is carried out, the cut-off current is 0.05C, finally the 1C constant current discharging is carried out until the voltage is 2.5V, the cycle test is carried out until the capacity is attenuated to 80%, and the test result is shown in figure 4.
FIG. 4 is a graph of capacity retention of the lithium ion battery C1-C6 at 25 ℃ under 3C/1C fast charging.
As can be seen from fig. 4, the capacity retention of the lithium ion battery C6 after about 400 cycles of water skipping, the capacity retention of the lithium ion battery C4/C5 after about 500/600 cycles of water skipping, and the capacity retention of the lithium ion battery C1-C3 after 800 cycles of water skipping are greater than 95%, and there is no sign of water skipping, especially the lithium ion battery C3, the cycle number of which is close to 1000 cycles, and the capacity retention is still maintained above 98%. Therefore, the cathode active material can reduce the polarization of the battery during high-current charging, reduce the risk of lithium precipitation, reduce the consumption of electrolyte and improve the cycle performance and safety performance of the quick-charging battery.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. A negative electrode active material, comprising a graphite intercalation compound and a coating layer that coats graphite in the graphite intercalation compound;
wherein the intercalation agent in the graphite intercalation compound and the material of the coating layer comprise a lithium-rich anti-perovskite material Li3OX, X are selected from at least one halogen atom.
2. The negative active material of claim 1, wherein the intercalant and the lithium-rich anti-perovskite material in the coating layer are the same.
3. The negative electrode active material of claim 1, wherein the lithium-rich anti-perovskite material Li in the negative electrode active material3The mass ratio of OX to graphite is (0.005-0.1): 1.
4. the negative electrode active material according to claim 1 or 2, wherein graphite is mixed with the lithium-rich anti-perovskite material Li3And (3) after OX is mixed and ground, the temperature is kept at 282-400 ℃, and the anode active material is obtained after cooling.
5. A method for preparing the negative active material of any one of claims 1 to 4, comprising the steps of:
1) graphite and lithium-rich anti-perovskite material Li3OX is mixed and ground to obtain a mixture;
2) and heating the mixture in a crucible or a stainless steel reaction kettle to 282-400 ℃, preserving heat and cooling to obtain the cathode active material.
6. The method for producing the anode active material according to claim 5, wherein in step 1), the lithium-rich anti-perovskite material Li3The mass ratio of OX to the graphite is (0.005-0.1): 1.
7. the method for preparing the anode active material according to claim 5, wherein the holding time is controlled to not less than 1 hour in the step 2).
8. The method for producing the anode active material according to any one of claims 5 to 7, wherein in step 2), the cooling includes: the temperature of the system is reduced to room temperature within 1-5 min.
9. A negative electrode sheet comprising the negative electrode active material according to any one of claims 1 to 4.
10. A lithium ion battery, wherein the negative electrode of the lithium ion battery is the negative electrode sheet according to claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010031172.0A CN111211303B (en) | 2020-01-13 | 2020-01-13 | Negative electrode active material and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010031172.0A CN111211303B (en) | 2020-01-13 | 2020-01-13 | Negative electrode active material and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111211303A CN111211303A (en) | 2020-05-29 |
| CN111211303B true CN111211303B (en) | 2021-04-13 |
Family
ID=70789027
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010031172.0A Active CN111211303B (en) | 2020-01-13 | 2020-01-13 | Negative electrode active material and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111211303B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112062991B (en) * | 2020-08-19 | 2023-03-28 | 上海纳米技术及应用国家工程研究中心有限公司 | Preparation method of organic-inorganic solid electrolyte |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6821675B1 (en) * | 1998-06-03 | 2004-11-23 | Matsushita Electric Industrial Co., Ltd. | Non-Aqueous electrolyte secondary battery comprising composite particles |
| CN109155411A (en) * | 2016-09-23 | 2019-01-04 | 株式会社Lg化学 | LCO class lithium compound, preparation method and the positive electrode active materials and lithium secondary battery comprising it that rich lithium anti-perovskite coats |
| CN109786822A (en) * | 2018-12-28 | 2019-05-21 | 南方科技大学 | A kind of richness lithium anti-perovskite oxide composite electrolyte and its preparation method and application |
| CN110233298A (en) * | 2019-07-09 | 2019-09-13 | 珠海冠宇电池有限公司 | A kind of preparation method of novel all-solid lithium-ion battery |
| CN110534796A (en) * | 2019-07-23 | 2019-12-03 | 珠海冠宇电池有限公司 | A kind of solid lithium battery and preparation method thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10008736B2 (en) * | 2012-10-23 | 2018-06-26 | Quantumscape Corporation | Method for forming and processing antiperovskite material doped with aluminum material |
-
2020
- 2020-01-13 CN CN202010031172.0A patent/CN111211303B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6821675B1 (en) * | 1998-06-03 | 2004-11-23 | Matsushita Electric Industrial Co., Ltd. | Non-Aqueous electrolyte secondary battery comprising composite particles |
| CN109155411A (en) * | 2016-09-23 | 2019-01-04 | 株式会社Lg化学 | LCO class lithium compound, preparation method and the positive electrode active materials and lithium secondary battery comprising it that rich lithium anti-perovskite coats |
| CN109786822A (en) * | 2018-12-28 | 2019-05-21 | 南方科技大学 | A kind of richness lithium anti-perovskite oxide composite electrolyte and its preparation method and application |
| CN110233298A (en) * | 2019-07-09 | 2019-09-13 | 珠海冠宇电池有限公司 | A kind of preparation method of novel all-solid lithium-ion battery |
| CN110534796A (en) * | 2019-07-23 | 2019-12-03 | 珠海冠宇电池有限公司 | A kind of solid lithium battery and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| "Antiperovskite Li3 OCl Superionic Conductor Films for Solid-State Li-Ion Batteries";Xujie Lü etal.,;《Adv. Sci. 》;20160202;全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111211303A (en) | 2020-05-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP7280942B2 (en) | Negative electrode materials and negative electrodes containing said negative electrode materials, and electrochemical devices | |
| CN110265627B (en) | Positive electrode plate and lithium ion secondary battery | |
| CN111129502B (en) | Negative pole piece and secondary battery | |
| JP7159459B2 (en) | lithium ion secondary battery | |
| CA2901265C (en) | Method for producing positive electrode active material layer for lithium ion battery, and positive electrode active material layer for lithium ion battery | |
| US11677074B2 (en) | Positive electrode plate, method for preparing the same and lithium-ion secondary battery | |
| CN105761944B (en) | A kind of hybrid super capacitor anode composite piece and preparation method thereof, hybrid super capacitor | |
| CN103151563A (en) | Polymer cell and preparation method thereof | |
| WO2023070992A1 (en) | Electrochemical device and electronic device comprising same | |
| CN110993901A (en) | Low-internal-resistance quick-charging and quick-discharging lithium ion power battery | |
| CN112467117B (en) | Lithium titanium aluminum phosphate coated graphite composite material, preparation method thereof and battery cathode | |
| CN111211303B (en) | Negative electrode active material and preparation method and application thereof | |
| CN114824165B (en) | Negative electrode plate, electrochemical device and electronic equipment | |
| WO2023040355A1 (en) | Negative electrode plate and preparation method therefor, secondary battery, battery module, battery pack and power-consuming apparatus | |
| CN108039453B (en) | Method for improving cycle performance of negative electrode of lithium battery by using coating | |
| CN112164804A (en) | Preparation method of composite modified lithium metal soft package battery | |
| CN114079080A (en) | Solid electrolyte membrane and preparation method thereof | |
| WO2024082264A1 (en) | Secondary battery, manufacturing method therefor, and electrical apparatus | |
| CN112467225B (en) | Preparation method of high-rate battery | |
| WO2024077607A1 (en) | Negative electrode active material and preparation method therefor, and secondary battery and electrical device containing negative electrode active material | |
| WO2023044625A1 (en) | Composite artificial graphite and preparation method therefor, secondary battery containing composite artificial graphite, and power-consuming apparatus | |
| WO2022193283A1 (en) | Electrochemical device and electronic device | |
| CN117613372A (en) | Secondary battery and electricity utilization device | |
| CN116598588A (en) | Electrolyte of lithium battery and application thereof | |
| CN117334831A (en) | Positive electrode active material, preparation method thereof, positive electrode plate and lithium 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 | ||
| CB02 | Change of applicant information |
Address after: 519180 No. 209 Pearl Peak Avenue, Jingan Town, Doumen District, Zhuhai City, Guangdong Province Applicant after: Zhuhai Guanyu Battery Co., Ltd Address before: 519180 No. 209 Pearl Peak Avenue, Jingan Town, Doumen District, Zhuhai City, Guangdong Province Applicant before: ZHUHAI COSLIGHT BATTERY Co.,Ltd. |
|
| CB02 | Change of applicant information | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |