CN111453779A - Method for reducing residual alkali content on surface of positive electrode material and application thereof - Google Patents
Method for reducing residual alkali content on surface of positive electrode material and application thereof Download PDFInfo
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- 239000003513 alkali Substances 0.000 title claims abstract description 87
- 239000007774 positive electrode material Substances 0.000 title claims abstract description 78
- 238000000034 method Methods 0.000 title claims abstract description 66
- 239000000463 material Substances 0.000 claims abstract description 106
- 239000002585 base Substances 0.000 claims abstract description 56
- KFDQGLPGKXUTMZ-UHFFFAOYSA-N [Mn].[Co].[Ni] Chemical compound [Mn].[Co].[Ni] KFDQGLPGKXUTMZ-UHFFFAOYSA-N 0.000 claims abstract description 26
- 239000011247 coating layer Substances 0.000 claims abstract description 21
- 239000011248 coating agent Substances 0.000 claims abstract description 20
- 238000002156 mixing Methods 0.000 claims abstract description 18
- 229910003002 lithium salt Inorganic materials 0.000 claims description 42
- 159000000002 lithium salts Chemical class 0.000 claims description 42
- 150000002696 manganese Chemical class 0.000 claims description 33
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 claims description 25
- 239000012298 atmosphere Substances 0.000 claims description 22
- 229910052744 lithium Inorganic materials 0.000 claims description 22
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 21
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 15
- 238000000227 grinding Methods 0.000 claims description 15
- 239000001301 oxygen Substances 0.000 claims description 15
- 229910052760 oxygen Inorganic materials 0.000 claims description 15
- 239000002243 precursor Substances 0.000 claims description 15
- 238000004146 energy storage Methods 0.000 claims description 10
- 229940071125 manganese acetate Drugs 0.000 claims description 7
- UOGMEBQRZBEZQT-UHFFFAOYSA-L manganese(2+);diacetate Chemical compound [Mn+2].CC([O-])=O.CC([O-])=O UOGMEBQRZBEZQT-UHFFFAOYSA-L 0.000 claims description 7
- 238000012216 screening Methods 0.000 claims description 7
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims description 3
- 229910021380 Manganese Chloride Inorganic materials 0.000 claims description 3
- GLFNIEUTAYBVOC-UHFFFAOYSA-L Manganese chloride Chemical compound Cl[Mn]Cl GLFNIEUTAYBVOC-UHFFFAOYSA-L 0.000 claims description 3
- YNQRWVCLAIUHHI-UHFFFAOYSA-L dilithium;oxalate Chemical compound [Li+].[Li+].[O-]C(=O)C([O-])=O YNQRWVCLAIUHHI-UHFFFAOYSA-L 0.000 claims description 3
- 238000010304 firing Methods 0.000 claims description 3
- CPSYWNLKRDURMG-UHFFFAOYSA-L hydron;manganese(2+);phosphate Chemical compound [Mn+2].OP([O-])([O-])=O CPSYWNLKRDURMG-UHFFFAOYSA-L 0.000 claims description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 claims description 3
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 claims description 3
- 229910052808 lithium carbonate Inorganic materials 0.000 claims description 3
- 229940099607 manganese chloride Drugs 0.000 claims description 3
- 235000002867 manganese chloride Nutrition 0.000 claims description 3
- 239000011565 manganese chloride Substances 0.000 claims description 3
- IPJKJLXEVHOKSE-UHFFFAOYSA-L manganese dihydroxide Chemical compound [OH-].[OH-].[Mn+2] IPJKJLXEVHOKSE-UHFFFAOYSA-L 0.000 claims description 3
- BHVPEUGTPDJECS-UHFFFAOYSA-L manganese(2+);diformate Chemical compound [Mn+2].[O-]C=O.[O-]C=O BHVPEUGTPDJECS-UHFFFAOYSA-L 0.000 claims description 3
- ZGIHUCQOMWIMKH-UHFFFAOYSA-L manganese(2+);propanoate Chemical compound [Mn+2].CCC([O-])=O.CCC([O-])=O ZGIHUCQOMWIMKH-UHFFFAOYSA-L 0.000 claims description 3
- 239000010406 cathode material Substances 0.000 abstract description 44
- 239000010405 anode material Substances 0.000 abstract description 32
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 abstract description 19
- 229910001416 lithium ion Inorganic materials 0.000 abstract description 19
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 30
- 230000000052 comparative effect Effects 0.000 description 29
- 239000000758 substrate Substances 0.000 description 16
- 229910052759 nickel Inorganic materials 0.000 description 14
- 239000011572 manganese Substances 0.000 description 10
- 238000012360 testing method Methods 0.000 description 10
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- 238000001354 calcination Methods 0.000 description 4
- 239000003153 chemical reaction reagent Substances 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- 229910017052 cobalt Inorganic materials 0.000 description 4
- 239000010941 cobalt Substances 0.000 description 4
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 4
- 238000001000 micrograph Methods 0.000 description 4
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- 239000002253 acid Substances 0.000 description 3
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- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 230000008025 crystallization Effects 0.000 description 2
- 125000004122 cyclic group Chemical group 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
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- 239000000126 substance Substances 0.000 description 2
- 208000019901 Anxiety disease Diseases 0.000 description 1
- 239000006245 Carbon black Super-P Substances 0.000 description 1
- 229910002983 Li2MnO3 Inorganic materials 0.000 description 1
- 229910001228 Li[Ni1/3Co1/3Mn1/3]O2 (NCM 111) Inorganic materials 0.000 description 1
- 229910000572 Lithium Nickel Cobalt Manganese Oxide (NCM) Inorganic materials 0.000 description 1
- 239000002033 PVDF binder Substances 0.000 description 1
- FBDMTTNVIIVBKI-UHFFFAOYSA-N [O-2].[Mn+2].[Co+2].[Ni+2].[Li+] Chemical compound [O-2].[Mn+2].[Co+2].[Ni+2].[Li+] FBDMTTNVIIVBKI-UHFFFAOYSA-N 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
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- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- CXULZQWIHKYPTP-UHFFFAOYSA-N cobalt(2+) manganese(2+) nickel(2+) oxygen(2-) Chemical compound [O--].[O--].[O--].[Mn++].[Co++].[Ni++] CXULZQWIHKYPTP-UHFFFAOYSA-N 0.000 description 1
- 238000005056 compaction Methods 0.000 description 1
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- 150000002500 ions Chemical class 0.000 description 1
- FUJCRWPEOMXPAD-UHFFFAOYSA-N lithium oxide Chemical compound [Li+].[Li+].[O-2] FUJCRWPEOMXPAD-UHFFFAOYSA-N 0.000 description 1
- 229910001947 lithium oxide Inorganic materials 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G53/00—Compounds of nickel
- C01G53/006—Compounds containing, besides nickel, two or more other elements, with the exception of oxygen or hydrogen
-
- 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
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- 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
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- 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
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
- H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
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- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
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- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
- H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
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- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
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Abstract
The invention discloses a method for reducing the content of residual alkali on the surface of a positive electrode material and application thereof. The method for reducing the content of the residual alkali on the surface of the cathode material comprises the following steps: mixing the nickel-cobalt-manganese ternary positive electrode base material with alkali residue on the surface with a coating agent, and roasting to enable the residual alkali on the surface of the positive electrode base material to react with the coating agent so as to form a coating layer on the surface of the positive electrode base material, thereby obtaining the positive electrode material with low alkali residue on the surface. The method can effectively solve the problem that the existing method for removing the residual alkali causes damage to the performance of the anode material and the environment, and can also improve the electrochemical performance, the safety performance and the service life of the lithium ion battery.
Description
Technical Field
The invention belongs to the field of lithium batteries, and particularly relates to a method for reducing the content of residual alkali on the surface of a positive electrode material and application thereof.
Background
At present, ternary cathode materials NCM111, NCM523 and NCM622 for lithium ion batteries are used in mass production, but the cathode materials adopted by the current mainstream battery technology still cannot completely meet the requirements of high energy density, long endurance mileage and the like, and in order to solve the problem of mileage anxiety, researchers are trying to develop a cathode material of a lithium ion battery with high energy density, such as NCM811 and the like, but the L i/Ni mixed arrangement phenomenon is aggravated along with the increase of the nickel content of the cathode material, in order to form a laminated structure well, an excessive lithium source needs to be put in the synthesis process, and L i is generated after synthesis2Unreacted lithium oxide in O state, which reacts with water and carbon dioxide in the air to form L iOH, L i2CO3And remains on the surface of the positive electrode material. However, the surface residual alkaline impurities greatly increased by the high-nickel cathode material can cause serious gas generation in the charging and discharging process of the lithium ion battery, so that the problems of expansion and deformation of the battery, shortened cycle shelf life, potential safety hazard and the like are caused. Therefore, the high residual alkali content on the surface of the high-nickel cathode material becomes one of the key factors restricting the application of the high-nickel cathode material in a high-energy density power battery.
Disclosure of Invention
The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, an object of the present invention is to provide a method for reducing the residual alkali content on the surface of a positive electrode material and an application thereof, so as to significantly reduce the residual alkali content on the surface of the positive electrode material and improve the electrochemical performance thereof.
The invention is mainly based on the following problems:
at present, the content of residual alkali on the surface of the cathode material is reducedThe method mainly comprises adjusting the synthesis process, and cleaning with deionized water or organic solvent to remove residual alkali on the surface of the positive electrode material, specifically, adjusting the synthesis process comprises adjusting the precursor of the positive electrode material and the lithium source (such as L iOH. H)2O or L i2CO3) The proportion, the reaction temperature and the reaction time of the lithium nickel cobalt manganese oxide positive electrode material are adjusted, at present, when a reaction mixture is sintered, a positive electrode material precursor is excessive in a synthesis reaction, the proportion of a lithium source is reduced, chemical reaction balance is moved along the direction of generating the positive electrode material, and the content of residual alkali in a final finished product is reduced, but the method can only reduce about 20% of residual alkali, is mainly used for fine adjustment and balance of the content and compaction density of the residual alkali in the nickel cobalt manganese oxide positive electrode material in actual production, cannot effectively improve the performance of the positive electrode material, for example, the lithium source may need to be added for several times, the preparation time is prolonged, the energy consumption is high, the cost is high, and the capacity; the reaction temperature is increased and the reaction time is prolonged to reduce the residual alkali on the surface of the cathode material, but the method easily causes the mixed discharge of lithium and nickel, especially for a high nickel material, thereby causing the unstable structure of the prepared cathode material and reducing the electrochemical performance of the material. In addition, weak acid reagents are adopted to clean the anode material, however, in the method, the weak acid reagents react with residual alkali on the surface to easily generate water, and the organic weak acid reagents have great harm to the environment and high cost in the using process. Therefore, the method for reducing the residual alkali content on the surface of the cathode material still needs to be further improved.
To this end, according to a first aspect of the present invention, the present invention proposes a method of reducing the residual alkali content on the surface of a positive electrode material. According to an embodiment of the invention, the method comprises:
mixing the nickel-cobalt-manganese ternary positive electrode base material with alkali residue on the surface with a coating agent, and roasting to enable the residual alkali on the surface of the positive electrode base material to react with the coating agent so as to form a coating layer on the surface of the positive electrode base material, thereby obtaining the positive electrode material with low alkali residue on the surface.
Further, the positive electrode base material is L iaNixCoyMn1-x-yO2Wherein, x isThe value range is 0.3-0.9, the value range of y is 0.1-0.35, and the value range of a is 0.95-1.03.
Further, the coating agent comprises a manganese salt and a first lithium salt, and the manganese salt reacts with the first lithium salt and the residual alkali on the surface of the positive electrode base material to form the coating layer.
Further, the manganese salt is at least one selected from the group consisting of manganese formate, manganese acetate, manganese propionate, manganese phosphate, manganese chloride and manganese hydroxide, and the first lithium salt is at least one selected from the group consisting of lithium hydroxide, lithium oxalate and lithium carbonate.
Further, the molar ratio of the positive electrode base material, the manganese salt, and the first lithium salt is 1: (0.005-0.1): (0.005-0.2).
Further, the molar ratio of the manganese salt to the first lithium salt is 1: (0.95 to 1.995). Further, the manganese salt is manganese acetate, the first lithium salt is lithium hydroxide, and the molar ratio of the positive electrode base material, the manganese salt and the first lithium salt is 1: (0.005-0.05): (0.009-0.1).
Further, the roasting treatment is carried out for 6-12 hours at 400-720 ℃ in an oxygen atmosphere.
Further, the nickel-cobalt-manganese ternary positive base material is obtained by mixing a nickel-cobalt-manganese ternary precursor material and a second lithium salt and roasting the mixture.
Further, the mixing roasting treatment of the nickel-cobalt-manganese ternary precursor material and the second lithium salt is carried out for 4-12 hours at 600-850 ℃ in an oxygen atmosphere.
Further, the molar ratio of the nickel-cobalt-manganese ternary precursor material to the second lithium salt is 1: (1.001-1.05). Further, the nickel-cobalt-manganese ternary precursor material is a hydroxide containing nickel, cobalt and manganese and/or a carbonate containing nickel, cobalt and manganese.
Further, the method for reducing the residual alkali content on the surface of the cathode material further comprises the following steps: and grinding and screening the positive electrode material.
Compared with the prior art, the method for reducing the content of the residual alkali on the surface of the cathode material has at least the following advantages: the coating agent reacts with the residual alkali on the surface of the anode base material to form a coating layer on the surface of the anode base material, so that the residual alkali on the surface of the anode base material can be consumed, the content of the residual alkali on the surface of the anode material is obviously reduced, the specific surface area of the anode material can be increased slightly, the side reaction of electrolyte and the anode base material at an interface is slowed down, the polarization problem of the anode material in charge-discharge circulation is reduced, the capacity attenuation problem of the material is improved, and the electrochemical performance of the anode material is improved. Therefore, the method not only can effectively solve the problem that the existing method for removing residual alkali causes damage to the performance of the anode material and the environment, but also can improve the electrochemical performance and the safety performance of the lithium ion battery and prolong the service life of the lithium ion battery.
The invention also aims to provide a positive electrode material to solve the problems of expansion deformation, shortened cycle shelf life and poor safety performance of a lithium battery caused by excessive residual alkali content on the surface of the positive electrode material in the charging and discharging processes.
In order to achieve the above object, according to a second aspect of the present invention, a positive electrode material is provided. According to the embodiment of the invention, the cathode material is obtained by adopting the method for reducing the residual alkali content on the surface of the cathode material. Compared with the prior art, the positive electrode material has low content of residual alkali on the surface, and the nickel-cobalt-manganese ternary positive electrode substrate material has a coating layer on the surface, so that the specific surface area is increased slightly, the side reaction of the electrolyte and the positive electrode substrate material at the interface can be effectively slowed down, the polarization problem of the positive electrode material in charge-discharge circulation is reduced, the capacity attenuation problem of the material is improved, the electrochemical performance of the positive electrode material is improved, and the lithium ion battery has good electrochemical performance, safety performance and long service life.
Another objective of the present invention is to provide a lithium battery to improve the electrochemical performance, safety performance and service life of the battery. In order to achieve the above object, according to a third aspect of the present invention, a lithium battery is provided. According to an embodiment of the invention, the lithium battery has the cathode material or the cathode material obtained by the method for reducing the residual alkali content on the surface of the cathode material. Compared with the prior art, the lithium battery provided by the invention is not easy to expand and deform in the charging and discharging processes, and has the advantages of good cycle stability, high safety and longer service life.
Another objective of the present invention is to provide an energy storage device to improve the cycle stability, safety performance and service life of the energy storage device. In order to achieve the above object, according to a fourth aspect of the present invention, an energy storage device is provided, which includes the above lithium battery or the above positive electrode material or the positive electrode material obtained by the above method for reducing the residual alkali content on the surface of the positive electrode material according to an embodiment of the present invention. Compared with the prior art, the energy storage equipment has the advantages of good cycle stability, high safety and longer service life.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a comparison graph showing the results of testing the residual alkali content on the surface of the positive electrode material obtained in examples 1 to 3 and comparative examples 1 to 2 of the present invention.
FIG. 2 is a comparison graph of the results of the measurements of the specific surface areas of the positive electrode materials obtained in examples 1 to 2 of the present invention and comparative examples 1 to 2.
FIG. 3 is a scanning electron micrograph of a positive electrode material obtained in comparative example 1 of the present invention.
FIG. 4 is a scanning electron micrograph of a positive electrode material obtained in comparative example 2 of the present invention.
FIG. 5 is a scanning electron micrograph of a positive electrode material obtained in example 1 of the present invention.
FIG. 6 is a further SEM image of the positive electrode material obtained in example 1 of the present invention.
FIG. 7 is a scanning electron micrograph of a positive electrode material obtained in example 2 of the present invention.
FIG. 8 is a scanning electron micrograph of a positive electrode material obtained in example 2 of the present invention.
Fig. 9 is a comparison graph of the first charge-discharge curves of button half cells prepared by using the positive electrode materials obtained in examples 1 to 2 of the present invention and comparative examples 1 to 2.
Fig. 10 is a graph comparing specific discharge capacity changes of button half cells prepared by using the positive electrode materials obtained in examples 1 to 2 and comparative examples 1 to 2 of the present invention in 50 charge-discharge cycles.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
According to a first aspect of the present invention, a method for reducing the residual alkali content on the surface of a positive electrode material is provided. According to an embodiment of the invention, the method comprises: mixing the nickel-cobalt-manganese ternary positive electrode base material with alkali residue on the surface with a coating agent, and roasting to enable the residual alkali on the surface of the positive electrode base material to react with the coating agent so as to form a coating layer on the surface of the positive electrode base material, thereby obtaining the positive electrode material with low alkali residue on the surface. Compared with the prior art, the method has the advantages that the coating agent reacts with the residual alkali on the surface of the anode base material to form the coating layer on the surface of the anode base material, so that the residual alkali on the surface of the anode base material can be consumed, the content of the residual alkali on the surface of the anode material is obviously reduced, the specific surface area of the anode base material can be increased slightly, the side reaction of the electrolyte and the anode base material at the interface is relieved, the polarization problem of the anode material in charge-discharge cycles is reduced, the capacity attenuation problem of the material is improved, and the electrochemical performance of the anode material is improved.
The method for reducing the residual alkali content on the surface of the positive electrode material according to the above embodiment of the present invention will be described in detail.
According to the inventionIn one embodiment, the nickel-cobalt-manganese ternary cathode base material may be L iaNixCoyMn1-x- yO2Wherein, the value range of x can be 0.3-0.9, the value range of y can be 0.1-0.35, and the value range of a can be 0.95-1.03. The inventor finds that the method for reducing the content of the residual alkali on the surface of the cathode material can achieve a good residual alkali removal effect on both the high-nickel ternary cathode base material and the ternary cathode base material with relatively low nickel content, so that the harm of the existing residual alkali removal method to the performance and the environment of the cathode material can be effectively solved, and the electrochemical performance, the safety performance and the service life of the lithium ion battery can be improved.
According to still another embodiment of the present invention, the coating agent may include a manganese salt and a first lithium salt, and the manganese salt reacts with the first lithium salt and a residual alkali on the surface of the cathode base material to form the coating layer. It should be noted that the types of the manganese salt and the first lithium salt in the present invention are not particularly limited, and those skilled in the art can select them according to the actual needs, only the manganese salt can simultaneously react with the residual alkali on the surface of the cathode substrate and the first lithium salt at a high temperature in a solid phase, for example, the manganese salt may be at least one selected from the group consisting of manganese formate, manganese acetate, manganese propionate, manganese phosphate, manganese chloride, and manganese hydroxide, the first lithium salt may be at least one selected from the group consisting of lithium hydroxide, lithium oxalate, and lithium carbonate, therefore, the residual alkali on the surface of the anode substrate material can participate in the reaction in the roasting treatment process, further remarkably reducing the residual alkali on the surface of the anode material, and enabling the manganese salt to react with the first lithium salt to form a coating layer, thereby slowing down the side reaction of the electrolyte and the anode matrix material at the interface and improving the electrochemical performance of the anode material.
According to still another embodiment of the present invention, the molar ratio of the positive electrode base material, the manganese salt, and the first lithium salt may be 1: (0.005-0.1): (0.005-0.2). The inventor finds that, compared with the cathode substrate material, if the ratio of the manganese salt to the first lithium salt is too small, the formation of a uniform and effective coating structure on the surface of the cathode substrate is not facilitated, the increase of the specific surface area of the cathode material is relatively large, side reactions with an electrolyte at an interface are increased, and the electrochemical performance of the cathode material is affected; if the ratio of the manganese salt to the first lithium salt is too large, the thickness of the coating layer is too large, the transmission speed of lithium ions is reduced, and the electrochemical performance of the cathode material is also affected. According to the invention, by controlling the molar ratio of the anode base material, the manganese salt and the first lithium salt, the alkali content on the surface of the anode material can be effectively reduced, the specific surface area of the anode base material is increased slightly, the side reaction between the anode base material and the electrolyte at the interface is reduced, the problem that the lithium ion transmission is influenced due to the excessively thick coating layer can be avoided, and the electrochemical performance of the anode material can be obviously improved. Further, the manganese salt may be in excess relative to the first lithium salt, for example, the molar ratio of manganese salt to first lithium salt may be 1: (0.95-1.995), so that the manganese salt can be further promoted to react with the residual alkali on the surface of the positive electrode material substrate, and the residual alkali content on the surface of the positive electrode material can be further reduced.
According to another embodiment of the present invention, when the cathode base material, the manganese salt, and the first lithium salt are mixed and subjected to the firing treatment, the manganese salt may be manganese acetate, the first lithium salt may be lithium hydroxide, and the mole ratio of the cathode base material, the manganese salt, and the first lithium salt may be 1: (0.005-0.05): (0.009-0.1), manganese acetate and lithium hydroxide are used as coating agents, and the molar ratio is controlled, so that manganese salt can react with residual alkali and first lithium salt on the surface of the positive electrode base material in the roasting treatment process to form MnO uniformly coated on the surface of the positive electrode base material2-Li2MnO3The substances can reduce the residual alkali on the surface of the anode base material, can also enable the specific surface area of the anode base material to be increased slightly, and reduce the side reaction between the anode base material and the electrolyte at the interface, thereby reducing the polarization problem of the anode material in charge-discharge cycles, obviously improving the capacity attenuation problem of the material, and simultaneously avoiding the problem that the lithium ion transmission is influenced due to the over-thick coating layer, thereby obviously improving the electrochemical performance of the anode material.
According to another embodiment of the present invention, when the cathode substrate, the manganese salt and the first lithium salt are mixed and baked, the baking process may be performed at 400-720 ℃ for 6-12 hours in an oxygen atmosphere, for example, the baking temperature may be 400 ℃, 440 ℃, 480 ℃, 520 ℃, 560 ℃, 600 ℃, 640 ℃, 680 ℃, or 720 ℃, and the baking time may be 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, or 12 hours, the inventors have found that if the baking temperature is too low, the generated coating layer has poor crystallization property, resulting in low ion conductivity of the coating layer, large lithium ion transmission resistance, and low specific capacity, and if the baking temperature is too high, the crystal structure of the coated cathode substrate is easily damaged, and L i/Ni mixing phenomenon is aggravated, and if the baking time is too short, the bonding strength of the coating layer and the substrate is insufficient, the crystal form is poor, and if the baking time is too long, the lithium ions in the internal structure of the coated cathode substrate are easily removed from the particle interior to the surface of the material, resulting in the cathode substrate, and the lithium ion transmission condition of the cathode substrate is controlled, resulting in good lithium ion transmission.
According to another embodiment of the present invention, the positive electrode material and the coating agent may be mechanically ground and uniformly mixed, and then subjected to a firing process, thereby further facilitating the formation of a uniform coating layer on the surface of the positive electrode substrate. Furthermore, after the roasting treatment, the positive electrode material with low residual alkali content on the surface can be ground and sieved, so that the electrochemical performance of the positive electrode material and the battery can be improved.
According to another embodiment of the present invention, the nickel-cobalt-manganese ternary positive base material may be obtained by mixing a nickel-cobalt-manganese ternary precursor material with a second lithium salt and performing a baking process, wherein the types of the nickel-cobalt-manganese ternary precursor material and the second lithium salt are not particularly limited, and may be selected by those skilled in the art according to actual needs, for example, the nickel-cobalt-manganese ternary precursor material may be a hydroxide containing nickel, cobalt and manganese, and/or a carbonate containing nickel, cobalt and manganese, and the like.
According to another embodiment of the present invention, the mixed calcination treatment of the nickel-cobalt-manganese ternary precursor material and the second lithium salt may be performed at 600-850 ℃ for 4-12 hours in an oxygen atmosphere, for example, the calcination temperature may be 600 ℃, 650 ℃, 700 ℃, 750 ℃, 800 ℃, or 850 ℃, and the calcination time may be 4 hours, 6 hours, 8 hours, 10 hours, or 12 hours. The inventor finds that if the roasting temperature is too low, the reaction is incomplete, an amorphous material is easy to generate, the crystallization performance of the coating material is poor, the coating material contains impurity phases, and if the roasting temperature is too high, an oxygen-deficient oxide is easy to generate, and the crystal grains of the material are too large, so that the extraction and the insertion of lithium ions are not facilitated; if the calcination time is too short or too long, the residual alkali content on the surface of the material and the particle size of the material particles are adversely affected. The roasting condition controlled in the invention is an optimization result after comprehensive consideration of physical and chemical properties such as material capacity, specific surface area, surface residual alkali content, tap density and the like, and can simultaneously reduce the surface residual alkali content of the anode material and improve the electrochemical performance of the anode material.
According to yet another embodiment of the present invention, the molar ratio of the nickel-cobalt-manganese ternary precursor material to the second lithium salt may be 1: (1.001-1.05). Therefore, when the nickel-cobalt-manganese anode material, particularly a high-nickel anode material is prepared, the mixed-arrangement phenomenon of lithium and nickel can be obviously improved, and the adverse effect on the anode material and the diffusion coefficient of lithium ions is greatly reduced.
In summary, compared with the prior art, the method for reducing the content of the residual alkali on the surface of the cathode material has at least the following advantages: the coating agent reacts with the residual alkali on the surface of the anode base material to form a coating layer on the surface of the anode base material, so that the residual alkali on the surface of the anode base material can be consumed, the content of the residual alkali on the surface of the anode material is obviously reduced, the specific surface area of the anode material can be increased slightly, the side reaction of electrolyte and the anode base material at an interface is slowed down, the polarization problem of the anode material in charge-discharge circulation is reduced, the capacity attenuation problem of the material is improved, and the electrochemical performance of the anode material is improved. Therefore, the method can effectively solve the problem that the existing method for removing residual alkali causes damage to the performance of the anode material and the environment, can improve the electrochemical performance, the safety performance and the service life of the lithium ion battery, has high feasibility, and is suitable for industrial mass production.
According to a second aspect of the present invention, a positive electrode material is provided. According to the embodiment of the invention, the cathode material is obtained by adopting the method for reducing the residual alkali content on the surface of the cathode material. Compared with the prior art, the content of residual alkali on the surface of the anode material is low, a coating layer is formed on the surface of the nickel-cobalt-manganese ternary anode base material, the specific surface area is increased slightly, side reaction between electrolyte and the anode base material at an interface can be effectively slowed down, the polarization problem of the anode material in charge-discharge circulation is reduced, the capacity attenuation problem of the material is improved, the electrochemical performance of the anode material is improved, and the lithium ion battery has good electrochemical performance, safety performance and long service life. It should be noted that the features and effects described for the method for reducing the residual alkali content on the surface of the positive electrode material are also applicable to the positive electrode material, and are not described in detail herein.
According to a third aspect of the present invention, a lithium battery is provided. According to an embodiment of the invention, the lithium battery has the cathode material or the cathode material obtained by the method for reducing the residual alkali content on the surface of the cathode material. Compared with the prior art, the lithium battery is not easy to expand and deform in the charging and discharging process, good in cycling stability, high in safety and longer in service life. It should be noted that the features and effects described for the above-mentioned cathode material and the method for reducing the content of the residual alkali on the surface of the cathode material are also applicable to the lithium battery, and are not described in detail herein.
According to a fourth aspect of the invention, the invention provides an energy storage device, which comprises the lithium battery or the cathode material obtained by the method for reducing the residual alkali content on the surface of the cathode material. Compared with the prior art, the energy storage device is good in cycle stability, high in safety and long in service life. It should be noted that the features and effects described for the lithium battery, the positive electrode material, and the method for reducing the content of the residual alkali on the surface of the positive electrode material are also applicable to the energy storage device, and are not repeated here. In addition, the type of the energy storage device in the present invention is not particularly limited, and those skilled in the art can select the type according to actual needs, for example, the energy storage device may be a battery pack or may be a device having a battery pack, such as a vehicle.
The scheme of the invention will be explained with reference to the examples. It will be appreciated by those skilled in the art that the following examples are illustrative of the invention only and should not be taken as limiting the scope of the invention. The examples, where specific techniques or conditions are not indicated, are to be construed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.
Comparative example 1
1mol of Ni was weighed0.835Co0.1074Mn0.0575(OH)2And 1.02mol of L iOH. H2And (3) placing the O into a mortar for fully grinding and uniformly mixing, then placing into a box-type atmosphere furnace for high-temperature sintering for 10 hours at 740 ℃ under an oxygen atmosphere, taking out the materials, and carrying out ultracentrifugal grinding and screening to obtain the final required anode material.
Comparative example 2
1mol of Ni was weighed0.835Co0.1074Mn0.0575(OH)2And 1.02mol of L iOH. H2Placing the O in a mortar for fully grinding and uniformly mixing, then placing in a box-type atmosphere furnace for high-temperature sintering at 740 ℃ in an oxygen atmosphere for 10 hours, taking out the material, and carrying out ultracentrifugal grinding and screening; weighing the anode material and deionized water in a weight ratio of 1:2, magnetically stirring and washing for about 30s, then carrying out vacuum filtration and vacuum drying at 150 ℃ for 10h to obtain the final required anode material.
Example 1
1mol of Ni was weighed0.835Co0.1074Mn0.0575(OH)2And 1.02mol of L iOH. H2Placing O in a mortar for fully grinding and uniformly mixing, then placing in a box-type atmosphere furnace for high-temperature sintering at 740 ℃ in an oxygen atmosphere for 10h, taking out the material, and carrying out ultracentrifugal grinding and screening to obtain the materialTo the positive electrode base material; 1mol of the positive electrode base material and 0.01mol of Mn (CH) were weighed3COO)2、0.02mol LiOH·H2And O, fully grinding and uniformly mixing the materials in a mortar, and then placing the materials in a box-type atmosphere furnace to perform high-temperature sintering for 6 hours at 700 ℃ in an oxygen atmosphere to obtain the final required cathode material.
Example 2
1mol of Ni was weighed0.835Co0.1074Mn0.0575(OH)2And 1.02mol of L iOH. H2Placing the O in a mortar for fully grinding and uniformly mixing, then placing in a box-type atmosphere furnace for high-temperature sintering at 740 ℃ in an oxygen atmosphere for 10h, taking out the material, and carrying out ultracentrifugal grinding and screening to obtain a positive electrode matrix material; 1mol of the positive electrode base material and 0.03mol of Mn (CH) were weighed3COO)2、0.06mol LiOH·H2And O, fully grinding and uniformly mixing the materials in a mortar, and then placing the materials in a box-type atmosphere furnace to perform high-temperature sintering for 6 hours at 700 ℃ in an oxygen atmosphere to obtain the final required cathode material.
Example 3
1mol of Ni was weighed0.835Co0.1074Mn0.0575(OH)2And 1.02mol of L iOH. H2Placing the O in a mortar for fully grinding and uniformly mixing, then placing in a box-type atmosphere furnace for high-temperature sintering at 740 ℃ in an oxygen atmosphere for 10 hours, taking out the material, and carrying out ultracentrifugal grinding and screening; 1mol of the positive electrode material and 0.03mol of Mn (CH) were weighed3COO)2、0.0598molLiOH·H2And O, fully grinding and uniformly mixing the materials in a mortar, and then placing the materials in a box-type atmosphere furnace to perform high-temperature sintering for 6 hours at 700 ℃ in an oxygen atmosphere to obtain the final required cathode material.
Evaluation of the positive electrode materials obtained in examples 1 to 3 and comparative examples 1 to 2 was carried out under the same conditions
1. The positive electrode materials obtained in examples 1 to 3 and comparative examples 1 to 2 were tested for residual alkali content on the surface
The test procedure was as follows: firstly, placing a powder sample in a vacuum oven at 100 ℃ for drying for 4h, placing 5g of the sample in 95g of deionized water solution, stirring for 5 minutes, then carrying out suction filtration, and using a potentialThe titrator calculates L i in the solution according to current point values V1 and V22CO3The content of (a).
The residual alkali content test results are shown in fig. 1, and the residual alkali contents on the surfaces of the positive electrode materials obtained in comparative example 1, comparative example 2, example 1, example 2 and example 3 are 2500ppm, 1800ppm, 1600ppm, 1800ppm and 1700ppm in sequence, so that the method for reducing the residual alkali content on the surfaces of the positive electrode materials in the above embodiments of the invention can achieve the effect of reducing the residual alkali content on the surfaces of the positive electrode materials similar to or better than the water washing process.
2. The positive electrode materials obtained in examples 1 to 2 and comparative examples 1 to 2 were tested for specific surface area
The test procedure was as follows: firstly, placing a powder sample in a vacuum oven at 100 ℃ for drying for 4h, degassing the sample at high temperature, weighing a proper amount of sample, and carrying out gas adsorption test to obtain a specific surface area value.
The results of the specific surface area test are shown in fig. 2, and the specific surface area values of the positive electrode materials obtained in comparative example 1, comparative example 2, example 1 and example 2 were 0.54m2/g，1.59m2/g，0.62m2/g，0.59m2The specific surface area of the positive electrode material obtained in examples 1-2 is obviously not much different from that of comparative example 1, so that compared with the method for reducing the residual alkali content on the surface of the positive electrode material by using a water washing process, the method for reducing the residual alkali content on the surface of the positive electrode material in the above embodiments of the present invention has less damage to the surface structure of the positive electrode material, and the specific surface area of the material is not changed much while the residual alkali on the surface of the positive electrode material is reduced, so that the generation of more byproducts in the charge and discharge cycle due to the excessively large specific surface area of the positive electrode material can be avoided, and thus the interface impedance and the polarization of the material are reduced, and the electrochemical performance of the material is improved to a.
3. Scanning electron microscope tests were performed on the positive electrode materials obtained in examples 1 to 2 and comparative examples 1 to 2
The test procedure was as follows: firstly, placing a powder sample in a vacuum oven at 100 ℃ for drying for 4h, taking out the powder sample, weighing a certain amount of the powder sample, adhering the powder sample on a sample table, and placing the powder sample into a sample cavity of an instrument. And (3) carrying out surface morphology tests under different magnifications under the condition of certain vacuum degree.
Wherein, the scanning electron microscope image of the cathode material obtained in comparative example 1 is shown in fig. 3, the scanning electron microscope image of the cathode material obtained in comparative example 2 is shown in fig. 4, the scanning electron microscope image of the cathode material obtained in example 1 is shown in fig. 5 and 6, and the scanning electron microscope image of the cathode material obtained in example 2 is shown in fig. 7 and 8. As can be seen from comparison of fig. 3 to 8, the uniform coating layers were formed on the surfaces of the positive electrode materials obtained in examples 1 and 2, which indicates that the coating material was formed on the surface of the positive electrode substrate after the positive electrode substrate was mixed with the manganese salt and the lithium salt and baked.
4. Electrical property evaluation of button type half cell was performed on the positive electrode materials obtained in examples 1-2 and comparative examples 1-2
The test procedure was as follows: the button cell was assembled with lithium metal sheets for the negative electrode in a glove box filled with argon. The positive pole piece consists of 92 wt% of active substances, 4 wt% of Super-P (namely superconducting carbon black) conductive agent and 4 wt% of PVDF (polyvinylidene fluoride) binder. Testing system for cyclic testing of charging and discharging: the voltage range is 3-4.3V, and the cyclic charge-discharge multiplying power of the first two circles is 0.1C; and then circulating for 50 times under the charge-discharge multiplying power of 0.5C and 1C respectively, and then returning to the charge-discharge multiplying power of 0.1C and 0.1C to circulate for 2 times.
Fig. 9 shows a comparison graph of the first charge-discharge curves of the button half cells prepared from the positive electrode materials obtained in examples 1 to 2 and comparative examples 1 to 2, where the button half cell corresponding to comparative example 1: the first charging specific capacity, the first discharging specific capacity and the first efficiency are 216.9 mA.h/g, 199.5 mA.h/g and 91.95 percent respectively; comparative example 1 corresponds to a button half-cell: the first charging specific capacity, the first discharging specific capacity and the first efficiency are 221.7 mA.h/g, 201.2 mA.h/g and 90.72 percent respectively; example 1 corresponding button half cell: the first charging specific capacity, the first discharging specific capacity and the first efficiency are 225.2 mA.h/g, 208.2 mA.h/g and 92.44 percent respectively; example 1 corresponding button half cell: the first charging specific capacity, the first discharging specific capacity and the first efficiency are 225.9 mA.h/g, 213.5 mA.h/g and 94.70 percent respectively. By comparison, the button-type half-cell prepared by the positive electrode material prepared by the embodiment of the invention has improved first charge specific capacity, first discharge specific capacity and first efficiency compared with the button-type half-cell prepared by the comparative example 1.
A comparison graph of discharge specific capacity changes of button half-cells prepared from the positive electrode materials obtained in examples 1-2 and comparative examples 1-2 in 50 charge-discharge cycles is shown in fig. 10, and under the same test conditions, the discharge specific capacities of the button half-cells corresponding to comparative examples 1, 2, 1 and 2 after 50 charge-discharge cycles are sequentially as follows: 192.1mA · h/g, 178.2mA · h/g, 200.2mA · h/g, 201.3mA · h/g, the discharge capacity of examples 1 and 2 is better than comparative examples 1-2; under the same test conditions, the capacity retention rates of the button half-cells corresponding to the comparative examples 1, 2, 1 and 2 after 50 charge and discharge cycles are 96.6%, 88.6%, 97.0% and 95.0% in sequence, which shows that the cycle stability of the cathode material obtained by the method for reducing the residual alkali content on the surface of the cathode material according to the embodiment of the invention is remarkably improved compared with the cycle stability of the cathode material according to the comparative example 2.
In the description of the present specification, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. Reference to the description of the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
Claims (10)
1. A method for reducing the residual alkali content on the surface of a positive electrode material is characterized by comprising the following steps:
mixing the nickel-cobalt-manganese ternary positive electrode base material with alkali residue on the surface with a coating agent, and roasting to enable the residual alkali on the surface of the positive electrode base material to react with the coating agent so as to form a coating layer on the surface of the positive electrode base material, thereby obtaining the positive electrode material with low alkali residue on the surface.
2. The method according to claim 1, wherein the positive electrode base material is L iaNixCoyMn1-x-yO2Wherein the value range of x is 0.3-0.9, the value range of y is 0.1-0.35, and the value range of a is 0.95-1.03.
3. The method according to claim 1 or 2, wherein the coating agent comprises a manganese salt and a first lithium salt, the manganese salt reacts with the first lithium salt and a residual alkali on the surface of the positive electrode base material to form the coating layer,
optionally, the manganese salt is at least one selected from the group consisting of manganese formate, manganese acetate, manganese propionate, manganese phosphate, manganese chloride, and manganese hydroxide, and the first lithium salt is at least one selected from the group consisting of lithium hydroxide, lithium oxalate, and lithium carbonate.
4. The method of claim 3, wherein the molar ratio of the positive electrode base material, the manganese salt, and the first lithium salt is 1: (0.005-0.1): (0.005-0.2),
optionally, the molar ratio of the manganese salt to the first lithium salt is 1: (0.95-1.995), optionally, the manganese salt is manganese acetate, the first lithium salt is lithium hydroxide, and the molar ratio of the positive electrode base material, the manganese salt and the first lithium salt is 1: (0.005-0.05): (0.009-0.1).
5. The method according to claim 1 or 4, wherein the baking treatment is performed at 400 to 720 ℃ for 6 to 12 hours in an oxygen atmosphere.
6. The method according to claim 5, wherein the nickel-cobalt-manganese ternary positive electrode base material is obtained by mixing a nickel-cobalt-manganese ternary precursor material with a second lithium salt and performing a firing treatment,
optionally, the mixing and roasting treatment of the nickel-cobalt-manganese ternary precursor material and the second lithium salt is carried out for 4-12 h at 600-850 ℃ in an oxygen atmosphere,
optionally, the molar ratio of the nickel-cobalt-manganese ternary precursor material to the second lithium salt is 1: (1.001 to 1.05),
optionally, the nickel-cobalt-manganese ternary precursor material is a hydroxide containing nickel-cobalt-manganese and/or a carbonate containing nickel-cobalt-manganese.
7. The method of claim 1 or 6, further comprising: and grinding and screening the positive electrode material.
8. A positive electrode material obtained by the method according to any one of claims 1 to 7.
9. A lithium battery comprising the positive electrode material according to claim 8 or the positive electrode material obtained by the method according to any one of claims 1 to 7.
10. An energy storage device comprising the lithium battery according to claim 9 or the positive electrode material according to claim 8 or the positive electrode material obtained by the method according to any one of claims 1 to 7.
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| CN114682575A (en) * | 2022-05-31 | 2022-07-01 | 宜宾锂宝新材料有限公司 | Method for reducing residual alkali on surface of high-nickel anode material, obtained material and application |
| CN117936771A (en) * | 2023-12-25 | 2024-04-26 | 贝特瑞（江苏）新材料科技有限公司 | Positive electrode material, preparation method thereof and lithium ion battery |
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| CN114682575B (en) * | 2022-05-31 | 2022-08-23 | 宜宾锂宝新材料有限公司 | Method for reducing residual alkali on surface of high-nickel anode material, obtained material and application |
| CN117936771A (en) * | 2023-12-25 | 2024-04-26 | 贝特瑞（江苏）新材料科技有限公司 | Positive electrode material, preparation method thereof and lithium ion battery |
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