CN113903894A - Composite cobalt-free positive electrode and preparation method and application thereof - Google Patents

Composite cobalt-free positive electrode and preparation method and application thereof Download PDF

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CN113903894A
CN113903894A CN202111134303.9A CN202111134303A CN113903894A CN 113903894 A CN113903894 A CN 113903894A CN 202111134303 A CN202111134303 A CN 202111134303A CN 113903894 A CN113903894 A CN 113903894A
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cobalt
free
composite
positive electrode
anode
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郭丰
乔齐齐
李子郯
杨红新
施泽涛
王鹏飞
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Svolt Energy Technology Co Ltd
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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
    • H01M4/364—Composites as mixtures
    • 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
    • H01M4/139—Processes of manufacture
    • H01M4/1391—Processes of manufacture of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • 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
    • H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
    • 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
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/621—Binders
    • H01M4/622—Binders being polymers
    • 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 composite cobalt-free anode and a preparation method and application thereof, wherein the preparation method comprises the following steps: the composite positive electrode material is mixed with an organic conductive material, and the modified composite cobalt-free positive electrode material is obtained after freeze drying, wherein the first cobalt-free material and the second cobalt-free material are different in type.

Description

Composite cobalt-free positive electrode and preparation method and application thereof
Technical Field
The invention belongs to the field of lithium ion batteries, and relates to a composite cobalt-free anode and a preparation method and application thereof.
Background
Under the background of current energy conservation, emission reduction and environmental protection, the development of a chemical power system with high energy density and high power density is urgent. Lithium-rich manganese-based layered oxides (LMROs) having a mass of more than 250mAh g-1The characteristics of high specific capacity, high working cost of 4.8V, high safety and the like are receiving more and more extensive attention from researchers. But the single cobalt-free lithium-rich material used for the first time has low coulombic efficiency, serious voltage attenuation and poor rate capability, so that the industrialization process of the material is restricted.
CN112133903A discloses a method for preparing a cobalt-free cathode material, which comprises the following steps (1) of preparing a cobalt-free cathode material precursor: (1a) mixing nickel salt and manganese salt solution, adding a nano additive, and performing ultrasonic treatment; (1b) adding the mixed solution into a reaction kettle in a nitrogen atmosphere, adding a mixed alkali solution of strong base and ammonia water, adjusting the pH to 9-12, reacting at the temperature of 40-60 ℃, and washing, filtering and drying after the reaction is finished; (2) and (3) high-temperature sintering: and (3) uniformly mixing lithium hydroxide and the powder obtained in the step (1b), calcining at the constant temperature of 700-1000 ℃ for 5-20 h, and naturally cooling to obtain the cobalt-free anode material. The single cobalt-free material is adopted, and in the circulation process, due to lattice oxygen release and structure conversion, the structure collapse is caused in the process of lithium ion intercalation and deintercalation, and in the process, part of free lithium ions are deposited on the surface, so that the circulation stability is poor, and the commercial application is difficult.
CN113072101A discloses a cobalt-free cathode material, a preparation method and an application thereof, wherein the preparation method comprises the following steps: (1) mixing lithium source and precursor NixMny(OH)2And mixingMixing the mixed agents, and carrying out primary heat treatment to obtain a base material; (2) and (2) mixing the base material obtained in the step (1) with a coating agent, and carrying out secondary heat treatment to obtain the cobalt-free anode material. It also uses single cobalt-free material, and has poor cycle stability.
The scheme adopts a single lithium-rich cobalt-free anode material, the voltage drop attenuation is serious, lithium ions cause structural collapse in the process of intercalation and deintercalation due to lattice oxygen release and structural transformation in the circulating process, and part of free lithium ions are deposited on the surface to cause poor circulating stability and difficult to realize commercial application, so that the development of the cobalt-free anode which has high circulating stability and can realize commercial application is necessary.
Disclosure of Invention
The invention aims to provide a composite cobalt-free anode, a preparation method and application thereof.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the present invention provides a method for preparing a composite cobalt-free positive electrode, comprising the steps of:
(1) mixing the first cobalt-free material and the second cobalt-free material with the coating material, and calcining to obtain a composite cathode material;
(2) mixing a composite positive electrode material with an organic conductive material, and freeze-drying to obtain the modified composite cobalt-free positive electrode material;
wherein the first cobalt-free material and the second cobalt-free material are different in kind.
The voltage drop attenuation of the single lithium-rich cobalt-free anode material is serious, the lithium ions cause structural collapse in the process of intercalation and deintercalation due to the release of lattice oxygen and structural transformation in the circulating process, and the circulating stability of the lithium-rich cobalt-free anode material is poor due to the deposition of partial free lithium ions on the surface, so that the lithium ion intercalation and deintercalation sites are difficult to be distributed to the maximum extent by adopting the composite electrode in the invention in a commercial application.
According to the invention, two anode materials are compounded and sintered again, so that the distribution of lithium can be improved, and the Li/Ni mixed-discharging degree can be reduced, thereby improving the cycle stability.
Preferably, the first cobalt-free material of step (1) is LixNiyMn1-yO2In which 1 is<x.ltoreq.1.3, for example: 1.02, 1.05, 1.1, 1.15, 1.2, etc., 0.4. ltoreq. y.ltoreq.0.9, for example: 0.4, 0.5, 0.6, 0.7, 0.8, or 0.9, etc.
The second cobalt-free material comprises LixNiyMn1-yO2And/or LiMPO4Where x ≦ 1, 0.4 ≦ y ≦ 0.9, such as: 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9, etc., and M comprises any one or a combination of at least two of Ni, Co, Fe, Mn, Al or Mg.
Preferably, the mass ratio of the first cobalt-free material to the second cobalt-free material is 1 (0.2-1), such as: 1:0.2, 1:0.3, 1:0.5, 1:0.8 or 1:1, etc.
Preferably, the clad material of step (1) comprises Al2O3、ZrO2、TiO2、Li2SiO3、Li4Ti5O12、LiV3O8、Li2ZrO3、SbO2、SnO、SnO2、Y2O3、H3BO3、MgO、ZnO、TiC、TiN、TiB2、ZrB2、TeO2Or TeO, or a combination of at least two thereof.
Preferably, the mass ratio of the total mass of the first cobalt-free material and the second cobalt-free material to the coating material is 1: 0.001-0.025, for example: 1:0.001, 1:0.005, 1:0.01, 1:0.015, 1:0.02 or 1:0.025, etc.
Preferably, the mixing speed is 2100-3000 rpm, for example: 2100rpm, 2200rpm, 2500rpm, 2800rpm, 3000rpm, or the like.
Preferably, the calcining temperature in the step (1) is 500-850 ℃, for example: 500 deg.C, 600 deg.C, 700 deg.C, 800 deg.C or 850 deg.C.
Preferably, the median particle diameter D50 of the composite cathode material after calcination is 2-8 μm, such as: 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, or the like.
Preferably, the organic conductive material in step (2) comprises any one of polyacetylene, polypyrrole, polythiophene, polyaniline or polyparaphenylene or a combination of at least two of the polyacetylene, the polypyrrole, the polythiophene, the polyaniline and the polyparaphenylene.
Preferably, the mass ratio of the composite cathode material to the organic conductive material is 1: 0.002-0.015, for example: 1:0.002, 1:0.005, 1:0.008, 1:0.01, 1:0.012 or 1:0.015, etc.
According to the invention, the organic conductive material is doped in the composite anode material, so that the conductivity of the composite anode material can be improved, the transmission efficiency and the volume change of lithium ions are improved, and the first effect and the average discharge voltage are improved.
Preferably, the freeze-drying is followed by a grinding process.
In a second aspect, the present invention provides a modified composite cobalt-free cathode material prepared by the method according to the first aspect.
In a third aspect, the present invention provides a composite cobalt-free positive electrode comprising the modified composite cobalt-free positive electrode material according to the second aspect.
In a fourth aspect, the present invention provides a method for preparing the composite cobalt-free positive electrode according to the third aspect, wherein the method comprises the following steps:
mixing the modified composite cobalt-free anode material with a binder solution and an organic solvent to obtain anode slurry, and coating the anode slurry on the surface of a current collector to obtain the composite cobalt-free anode.
Preferably, the binder solution in step (1) is a mixture of a binder and an organic solvent.
Preferably, the solid content of the binder solution is 6-7.05%, for example: 6%, 6.05%, 6.2%, 6.5%, 6.8%, 7.05%, etc
Preferably, the binder in the binder solution comprises any one or a combination of at least two of starch, dextrin, polyvinyl alcohol, carboxymethyl cellulose, 2 ethylhexylacrylonitrile acrylate, styrene-butylene, polyacrylonitrile-methyl acrylate, polyimide, polyacrylic acid, or polyacrylate.
Preferably, the current collector in step (3) comprises any one of or a combination of at least two of single metals or alloys of aluminum, titanium, tantalum, gold, silver, platinum and zirconium.
Preferably, the thickness of the current collector is 20-30 μm, for example: 20 μm, 22 μm, 25 μm, 28 μm, 30 μm, or the like.
Preferably, the thickness of the coated positive electrode slurry in the step (3) is 0.5-2 μm, for example: 0.5 μm, 0.8 μm, 1 μm, 1.5 μm, 2 μm, or the like.
Preferably, the coating is followed by a roll treatment.
Preferably, the compacted density of the rolled pole piece is 3-5 g/cm3For example: 3g/cm3、3.5g/cm3、4g/cm3、4.5g/cm3Or 5g/cm3And the like.
In a fifth aspect, the present invention provides a lithium ion battery comprising a composite cobalt-free positive electrode according to the third aspect.
Compared with the prior art, the invention has the following beneficial effects:
(1) the invention adopts the composite secondary sintering of two anode materials, can improve the distribution of lithium, can reduce the Li/Ni mixed discharging degree, thereby improving the cycling stability, and has different binding forces between different materials and the coating agent, so the composite anode material can enhance the binding force between the coating agent and the composite electrode, and avoid the phenomenon of falling off of the coating agent in the subsequent process.
(2) According to the invention, the two anode materials are compounded and sintered again, so that the gas production risk of the battery can be uniformized, the gas production of the single crystal anode material is low, the voltage is reduced, but the capacity and the cycle performance are poor, and the capacity and the cycle performance of the lithium-rich anode material are moderate, but the large voltage drop risk exists, and the voltage drop of the lithium-rich anode material and the gas production risk of the whole material can be reduced by compounding the two anode materials.
Drawings
Fig. 1 is an SEM image of the composite positive electrode material according to example 1 of the present invention.
Detailed Description
The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.
Example 1
The embodiment provides a composite cobalt-free anode, and a preparation method of a hydrogen composite cobalt-free anode comprises the following steps:
(1) 30g of Li with a D50 of 3.5 μm were taken1.25Ni0.25Mn0.75O230g D50 is 4 μm Li1.05Ni0.8Mn0.2O2And 0.12g D50 TiO 100nm2The composite anode material is prepared by mixing the materials for 30min at 2000r/min by a high-speed mixer, putting the mixture into a box-type atmosphere furnace after mixing, and sintering the mixture for 5h at 800 ℃ to obtain the composite anode material, wherein an SEM image of the composite anode material is shown in figure 1;
(2) uniformly mixing 50g of the composite anode material with 0.2g of polyaniline, freeze-drying the mixture by using a freeze dryer, grinding the mixture into powder, uniformly mixing 1g of the composite anode powder, 0.51g of 6.25% binder and 0.8g of NMP solution at the speed of 2000r/min by using a high-speed defoaming machine for 10min to obtain anode slurry;
(3) coating the positive electrode slurry on an aluminum foil with the thickness of 20 mu m, wherein the thickness of the coated positive electrode is 21.2 mu m, putting the aluminum foil into a 100 ℃ oven, drying for 10h, and then pressing the aluminum foil to 4.0g/cm after rolling by a roller press3And obtaining the composite cobalt-free anode.
Example 2
The embodiment provides a composite cobalt-free anode, and a preparation method of a hydrogen composite cobalt-free anode comprises the following steps:
(1) 30g of Li with a D50 value of 4 μm1.25Ni0.25Mn0.75O2And 30g D50 is LiNi of 3 μm0.4Mn0.6O2And ZrO with 0.12g D50 being 100nm2The composite anode material is prepared by mixing the materials for 30min at 2000r/min by a high-speed mixer, putting the mixture into a box-type atmosphere furnace after mixing, and sintering the mixture for 5h at 800 ℃;
(2) uniformly mixing 50g of the composite anode material with 0.2g of polyaniline, freeze-drying the mixture by using a freeze dryer, grinding the mixture into powder, uniformly mixing 1g of the composite anode powder, 0.51g of 6.25% binder and 0.8g of NMP solution at the speed of 2000r/min by using a high-speed defoaming machine for 10min to obtain anode slurry;
(3) coating the positive electrode slurry on an aluminum foil with the thickness of 20 mu m, wherein the thickness of the coated positive electrode is 21.2 mu m, putting the aluminum foil into a 100 ℃ oven, drying for 10h, and then pressing the aluminum foil to 3.5g/cm after rolling by a roller press3And obtaining the composite cobalt-free anode.
Example 3
The embodiment provides a composite cobalt-free anode, and a preparation method of a hydrogen composite cobalt-free anode comprises the following steps:
(1) 30g of Li with a D50 of 3.5 μm were taken1.25Ni0.25Mn0.75O230g D50 is 3 μm LiFePO4And 0.12g D50 is H at 200nm3BO3The composite anode material is prepared by mixing the materials for 30min at 2000r/min by a high-speed mixer, putting the mixture into a box-type atmosphere furnace after mixing, and sintering the mixture for 5h at 800 ℃;
(2) uniformly mixing 50g of the composite anode material with 0.2g of polyaniline, freeze-drying the mixture by using a freeze dryer, grinding the mixture into powder, uniformly mixing 1g of the composite anode powder, 0.51g of 6.25% binder and 0.8g of NMP solution at the speed of 2000r/min by using a high-speed defoaming machine for 10min to obtain anode slurry;
(3) coating the positive electrode slurry on an aluminum foil with the thickness of 20 mu m, wherein the thickness of the coated positive electrode is 20.8 mu m, putting the aluminum foil into a 100 ℃ oven, drying for 10h, and then passing through a roller press to roll the aluminum foilCompacting to 3.5g/cm3And obtaining the composite cobalt-free anode.
Example 4
The embodiment provides a composite cobalt-free anode, and a preparation method of a hydrogen composite cobalt-free anode comprises the following steps:
(1) 30g of Li with a D50 of 3.5 μm were taken1.25Ni0.25Mn0.75O230g D50 LiFePO 3.5 μm4And 0.12g D50 SnO at 200nm2The composite anode material is prepared by mixing the materials for 30min at 2000r/min by a high-speed mixer, putting the mixture into a box-type atmosphere furnace after mixing, and sintering the mixture for 5h at 7300 ℃;
(2) uniformly mixing 50g of the composite anode material with 0.2g of polyaniline, freeze-drying the mixture by using a freeze dryer, grinding the mixture into powder, uniformly mixing 1g of the composite anode powder, 0.51g of 6.25% binder and 0.8g of NMP solution at the speed of 2000r/min by using a high-speed defoaming machine for 10min to obtain anode slurry;
(3) coating the positive electrode slurry on an aluminum foil with the thickness of 20 mu m, wherein the thickness of the coated positive electrode is 21.2 mu m, putting the aluminum foil into a 100 ℃ oven, drying for 10h, and then pressing the aluminum foil to 4.0g/cm after rolling by a roller press3And obtaining the composite cobalt-free anode.
Example 5
The embodiment provides a composite cobalt-free anode, and a preparation method of a hydrogen composite cobalt-free anode comprises the following steps:
(1) 30g of Li with a D50 of 3.5 μm were taken1.25Ni0.25Mn0.75O230g D50 LiNi of 3.5 μm0.75Mn0.25O2And ZrO with 0.12g D50 being 200nm2The composite anode material is prepared by mixing the materials for 30min at 2000r/min by a high-speed mixer, putting the mixture into a box-type atmosphere furnace after mixing, and sintering the mixture for 5h at 7300 ℃;
(2) uniformly mixing 50g of the composite anode material with 0.2g of polyaniline, freeze-drying the mixture by using a freeze dryer, grinding the mixture into powder, uniformly mixing 1g of the composite anode powder, 0.51g of 6.25% binder and 0.8g of NMP solution at the speed of 2000r/min by using a high-speed defoaming machine for 10min to obtain anode slurry;
(3) coating the positive electrode slurry on an aluminum foil with the thickness of 20 mu m, wherein the thickness of the coated positive electrode is 21.2 mu m, putting the aluminum foil into a 100 ℃ oven, drying for 10h, and then pressing the aluminum foil to 4.0g/cm after rolling by a roller press3And obtaining the composite cobalt-free anode.
Example 6
The embodiment provides a composite cobalt-free anode, and a preparation method of a hydrogen composite cobalt-free anode comprises the following steps:
(1) 30g of Li with a D50 of 3.5 μm were taken1.25Ni0.25Mn0.75O2And 30g D50 is LiNi of 5 μm0.75Mn0.25O2And ZrO with 0.12g D50 being 200nm2The composite anode material is prepared by mixing the materials for 30min at 2000r/min by a high-speed mixer, putting the mixture into a box-type atmosphere furnace after mixing, and sintering the mixture for 5h at 7300 ℃;
(2) uniformly mixing 50g of the composite anode material with 0.2g of polyaniline, freeze-drying the mixture by using a freeze dryer, grinding the mixture into powder, uniformly mixing 1g of the composite anode powder, 0.51g of 6% binder and 0.8g of NMP solution by using a high-speed defoaming machine at the speed of 2000r/min for 10min to obtain anode slurry;
(3) coating the positive electrode slurry on an aluminum foil with the thickness of 20 mu m, wherein the thickness of the coated positive electrode is 21 mu m, putting the aluminum foil into a 100 ℃ oven, drying for 10h, and then pressing the aluminum foil to 3.0g/cm through a roller press after rolling3And obtaining the composite cobalt-free anode.
Example 7
This example differs from example 1 only in that the TiO described in step (1)2The mass of (2) was 0.05g, and the other conditions and parameters were exactly the same as those in example 1.
Example 8
This example differs from example 1 only in that the TiO described in step (1)2The mass of (2) was 0.18g, and the other conditions and parameters were exactly the same as those in example 1.
Example 9
This example is different from example 1 only in that the mass of polyaniline in step (2) is 0.1g, and other conditions and parameters are exactly the same as those in example 1.
Example 10
This example is different from example 1 only in that the mass of polyaniline in step (2) is 1g, and other conditions and parameters are exactly the same as those in example 1.
Comparative example 1
This comparative example differs from example 1 only in that step (1) does not add Li1.05Ni0.8Mn0.2O2Other conditions and parameters were exactly the same as those in example 1.
Comparative example 2
This comparative example differs from example 1 only in that no coating material was added in step (1) and the other conditions and parameters were exactly the same as in example 1.
Comparative example 3
This comparative example is different from example 1 only in that the polyaniline in step (2) was changed to an inorganic conductive material, acetylene black, and the other conditions and parameters were exactly the same as those in example 1.
And (3) performance testing:
the composite cobalt-free positive electrodes obtained in examples 1 to 10 and comparative examples 1 to 3 were fabricated into batteries, and performance tests were performed, the test results being shown in table 1:
TABLE 1
Figure BDA0003281687330000101
Figure BDA0003281687330000111
As can be seen from table 1, in examples 1 to 10, the capacity retention rate of the battery manufactured by using the composite cobalt-free positive electrode of the present invention can reach 90.6% or more at 0.1C for 50 weeks, the median voltage at 50 weeks can reach 3.72V or more, the voltage decay at 50 weeks can reach 0.8% or less, and the first effect at 0.1C can reach 86.5% or more.
Compared with the examples 1 and 7 to 8, the mass ratio of the total mass of the first cobalt-free material and the second cobalt-free material to the coating material affects the performance of the prepared positive plate, the mass ratio of the total mass of the first cobalt-free material and the second cobalt-free material to the coating material is controlled to be 1: 0.001-0.025, the performance of the prepared positive plate is excellent, if the mass ratio of the total mass of the first cobalt-free material and the second cobalt-free material to the coating material is too low, the cycle performance is reduced by about 3%, and if the mass ratio of the total mass of the first cobalt-free material and the second cobalt-free material to the coating material is too high, the initial efficiency is reduced by 3% at 0.1 ℃.
Compared with the examples 9 to 10, the mass ratio of the composite positive electrode material to the organic conductive material affects the performance of the prepared positive electrode plate, if the addition amount of the organic conductive material is too large, the initial effect of 0.1C is reduced by 3%, and if the addition amount of the organic conductive material is too small, the voltage drop is increased by 0.5%.
Compared with the comparative example 1, the invention adopts the composite re-sintering of the two cathode materials, can improve the distribution of lithium, can reduce the Li/Ni mixed discharging degree, and thus improves the cycling stability.
Compared with the embodiment 1 and the comparative example 2, the binding force between different materials and the coating agent is different, so that the binding force between the coating agent and the composite electrode can be enhanced by adopting the composite anode material, and the phenomenon that the coating agent falls off in the subsequent process is avoided.
Compared with the comparative example 3, the organic conductive material is doped in the composite cathode material, so that the conductivity of the composite cathode material can be improved, the transmission efficiency and the volume change of lithium ions are improved, and the first effect and the average discharge voltage are improved.
The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.

Claims (10)

1. A preparation method of a modified composite cobalt-free cathode material is characterized by comprising the following steps:
(1) mixing the first cobalt-free material and the second cobalt-free material with the coating material, and calcining to obtain a composite cathode material;
(2) mixing a composite positive electrode material with an organic conductive material, and freeze-drying to obtain the modified composite cobalt-free positive electrode material;
wherein the first cobalt-free material and the second cobalt-free material are different in kind.
2. The method of claim 1, wherein the first cobalt-free material of step (1) is LixNiyMn1- yO2In which 1 is<x≤1.3，0.4≤y≤0.9；
Preferably, the second cobalt-free material comprises LixNiyMn1-yO2And/or LiMPO4Wherein x is 1, y is more than or equal to 0.4 and less than or equal to 0.9, and M comprises any one or the combination of at least two of Ni, Co, Fe, Mn, Al or Mg;
preferably, the mass ratio of the first cobalt-free material to the second cobalt-free material is 1 (0.2-1).
3. The method according to claim 1 or 2, wherein the clad material of step (1) comprises Al2O3、ZrO2、TiO2、Li2SiO3、Li4Ti5O12、LiV3O8、Li2ZrO3、SbO2、SnO、SnO2、Y2O3、H3BO3、MgO、ZnO、TiC、TiN、TiB2、ZrB2、TeO2Or TeO or a combination of at least two of the above;
preferably, the mass ratio of the total mass of the first cobalt-free material and the second cobalt-free material to the coating material is 1:0.001 to 0.025;
preferably, the mixing speed is 2100-3000 rpm.
4. The method according to any one of claims 1 to 3, wherein the calcination in the step (1) is carried out at a temperature of 500 to 850 ℃;
preferably, the median particle diameter D50 of the composite cathode material after calcination is 2-8 μm.
5. The production method according to any one of claims 1 to 4, wherein the organic conductive material of step (2) comprises any one of polyacetylene, polypyrrole, polythiophene, polyaniline, or polyparaphenylene, or a combination of at least two thereof;
preferably, the mass ratio of the composite positive electrode material to the organic conductive material is 1: 0.002-0.015;
preferably, the freeze-drying is followed by a grinding process.
6. A modified composite cobalt-free cathode material, characterized in that it is obtainable by a process according to any one of claims 1 to 5.
7. A composite cobalt-free positive electrode, characterized in that the composite cobalt-free positive electrode comprises the modified composite cobalt-free positive electrode material of claim 6.
8. A method of making the composite cobalt-free positive electrode of claim 7, comprising the steps of:
mixing the modified composite cobalt-free anode material with a binder solution and an organic solvent to obtain anode slurry, and coating the anode slurry on the surface of a current collector to obtain the composite cobalt-free anode.
9. The method of claim 8, wherein the binder solution is a mixture of a binder and an organic solvent;
preferably, the solid content of the binder solution is 6-7.05%;
preferably, the binder in the binder solution comprises any one or a combination of at least two of starch, dextrin, polyvinyl alcohol, carboxymethyl cellulose, 2 ethylhexylacrylonitrile, styrene-butylene, polyacrylonitrile-methyl acrylate, polyimide, polyacrylic acid or polyacrylate;
preferably, the current collector in step (2) comprises any one of or a combination of at least two of single metals or alloys of aluminum, titanium, tantalum, gold, silver, platinum and zirconium;
preferably, the thickness of the current collector is 20-30 μm;
preferably, the thickness of the coated positive electrode slurry in the step (3) is 0.5-2 μm;
preferably, the coating is followed by a rolling treatment;
preferably, the compacted density of the rolled pole piece is 3-5 g/cm3。
10. A lithium ion battery comprising the composite cobalt-free positive electrode of claim 7.
CN202111134303.9A 2021-09-27 2021-09-27 Composite cobalt-free positive electrode and preparation method and application thereof Pending CN113903894A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114583176A (en) * 2022-05-06 2022-06-03 华中科技大学 Multifunctional novel conductive agent and application thereof in pre-lithiation composite positive electrode

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101409342A (en) * 2008-10-31 2009-04-15 深圳市贝特瑞新能源材料股份有限公司 Method for preparing composite anode material
US20130280610A1 (en) * 2012-04-24 2013-10-24 Lg Chem, Ltd. Active material for lithium secondary battery composite electrode for improving output and lithium secondary battery including the active material
CN103943844A (en) * 2014-04-04 2014-07-23 西安交通大学 Cobalt-free lithium-rich manganese-based cathode material as well as preparation method and application thereof
US20160020458A1 (en) * 2014-07-18 2016-01-21 Samsung Electronics Co., Ltd. Composite positive electrode active material, positive electrode including the same, and lithium battery including the positive electrode
CN111916697A (en) * 2020-07-14 2020-11-10 蜂巢能源科技有限公司 Cobalt-free cathode material, preparation method thereof, lithium ion battery cathode and lithium battery

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101409342A (en) * 2008-10-31 2009-04-15 深圳市贝特瑞新能源材料股份有限公司 Method for preparing composite anode material
US20130280610A1 (en) * 2012-04-24 2013-10-24 Lg Chem, Ltd. Active material for lithium secondary battery composite electrode for improving output and lithium secondary battery including the active material
CN103943844A (en) * 2014-04-04 2014-07-23 西安交通大学 Cobalt-free lithium-rich manganese-based cathode material as well as preparation method and application thereof
US20160020458A1 (en) * 2014-07-18 2016-01-21 Samsung Electronics Co., Ltd. Composite positive electrode active material, positive electrode including the same, and lithium battery including the positive electrode
CN111916697A (en) * 2020-07-14 2020-11-10 蜂巢能源科技有限公司 Cobalt-free cathode material, preparation method thereof, lithium ion battery cathode and lithium battery

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
高旭光等: "LiFePO_4-LiMn_2O_4混合正极材料对电池性能的影响", 《电源技术》 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114583176A (en) * 2022-05-06 2022-06-03 华中科技大学 Multifunctional novel conductive agent and application thereof in pre-lithiation composite positive electrode

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