A lithium-ion battery cell and related methods of manufacture, battery and electric device

Abstract

A lithium-ion battery cell and related preparation methods, batteries, and power devices are disclosed. The lithium-ion battery cell includes a positive electrode sheet comprising a lithium-rich manganese-based positive electrode material. The lithium-rich manganese-based positive electrode material comprises spherical bodies formed by primary particle stacking and needle-like clusters formed by linearly arranged primary particles, with the needle-like clusters radially distributed on the surface of the spherical bodies. The diameter of the spherical bodies is 1 μm to 5 μm, and the length of the needle-like clusters is 1 μm to 7 μm. In this application, the lithium-rich manganese-based positive electrode material in the lithium-ion battery cell has a special radial morphology. By controlling the appropriate diameter of the spherical bodies and the length of the needle-like clusters, the specific surface area of ​​the lithium-rich manganese-based positive electrode material can be increased, facilitating rapid lithium-ion insertion and extraction, increasing the lithium-ion diffusion rate, and thus improving the rate performance of the lithium-ion battery cell.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a lithium-ion battery cell and related preparation methods, battery, and power-consuming device. Background Technology

[0002] With increasing environmental pollution, the new energy industry is attracting more and more attention. Within the new energy industry, battery technology is a crucial factor in its development.

[0003] In recent years, rechargeable batteries have seen significant development due to their high energy density and long lifespan, finding widespread application in power tools, electronic products, electric vehicles, aerospace, and other fields. The development of battery technology requires consideration of various design factors, such as energy density, cycle life, capacity, and safety and reliability. In lithium-ion battery cells, some cathode materials, such as lithium-rich manganese-based cathode materials, have low ionic and electronic conductivity, resulting in poor rate performance. Therefore, improving the rate performance of lithium-ion battery cells is a pressing technical problem that needs to be solved. Summary of the Invention

[0004] This application is made in view of the above-mentioned problems, and its purpose is to provide a lithium-ion battery cell and related preparation methods, batteries and power devices, which is beneficial to increase the lithium-ion diffusion rate of lithium-rich manganese-based cathode materials in lithium-ion battery cells and improve the rate performance of lithium-ion battery cells.

[0005] To achieve the above objectives, in a first aspect, a lithium-ion battery cell is provided, comprising: a positive electrode sheet, the positive electrode sheet comprising a lithium-rich manganese-based positive electrode material. The lithium-rich manganese-based positive electrode material comprises spherical bodies formed by the stacking of primary particles and needle-like clusters formed by the linear arrangement of primary particles, the needle-like clusters being radially distributed on the surface of the spherical bodies. The diameter of the spherical bodies is between 1 μm and 5 μm, and the length of the needle-like clusters is between 1 μm and 7 μm.

[0006] In the technical solution of this application, the lithium-rich manganese-based cathode material in the lithium-ion battery cell has a special radial morphology. By controlling the appropriate spherical diameter and needle cluster length of the lithium-rich manganese-based cathode material, it is beneficial to improve the structural stability of the lithium-rich manganese-based cathode material, improve the specific surface area of ​​the lithium-rich manganese-based cathode material, facilitate the rapid insertion and extraction of lithium ions, increase the diffusion rate of lithium ions, and thus improve the rate performance of the lithium-ion battery cell.

[0007] Secondly, a method for preparing a lithium-ion battery cell is provided, wherein a transition metal salt, a complexing agent, and a surfactant are co-precipitated to obtain a lithium-rich manganese-based cathode material precursor. The complexing agent includes compounds with carboxyl and hydroxyl groups, or compounds with carboxyl and amino groups, and the mass ratio A of the surfactant to the transition metal salt satisfies: 1:1000 ≤ A ≤ 1:20. The prepared lithium-rich manganese-based cathode material precursor is used to prepare a lithium-rich manganese-based cathode material with a morphology of spherical bodies formed by primary particle stacking and needle-like clusters formed by radially distributed primary particles on the surface of the spherical bodies. A positive electrode sheet, a separator, and a negative electrode sheet are provided. The positive electrode sheet preparation includes: coating a slurry containing the lithium-rich manganese-based cathode material onto the surface of a positive current collector to prepare the positive electrode sheet; assembling the prepared positive electrode sheet, separator, and negative electrode sheet sequentially to prepare an electrode assembly; and using this electrode assembly to prepare a lithium-ion battery cell.

[0008] In this embodiment, the complexing agent compound contains carboxyl and hydroxyl groups or carboxyl and amino groups, which can effectively complex transition metal ions, control crystal growth rate and the generation of new crystal nuclei. Furthermore, the complex is physically and chemically stable, not easily volatilized or decomposed, which is beneficial for the preparation of lithium-rich manganese-based cathode material precursors. In addition, adding a suitable proportion of surfactant during the preparation process promotes radial grain growth and works synergistically with the complexing agent to further promote primary particle growth, improve the dispersion degree and production efficiency of the lithium-rich manganese-based cathode material precursor, and obtain a lithium-rich manganese-based cathode material precursor with a radial morphology. Using this radially morphological lithium-rich manganese-based cathode material precursor, lithium-rich manganese-based cathode materials with spherical bodies formed by primary particle stacking and needle-like clusters formed by radially distributed primary particles on the surface of the spherical bodies can be prepared. Using this lithium-rich manganese-based cathode material to prepare lithium-ion battery cells can improve the rate performance of lithium-ion battery cells.

[0009] Thirdly, a cathode material is provided, which is a lithium-rich manganese-based cathode material. This lithium-rich manganese-based cathode material includes spherical bodies formed by the stacking of primary particles and needle-like clusters formed by the linear arrangement of primary particles. The needle-like clusters are radially distributed on the surface of the aforementioned spherical bodies. The diameter of the spherical bodies is between 1 μm and 5 μm, and the length of the needle-like clusters is between 1 μm and 7 μm.

[0010] In the above technical solution, the lithium-rich manganese-based cathode material has a special radial morphology. By controlling the appropriate diameter of the spheres and the length of the needle clusters, it is beneficial to improve the structural stability of the lithium-rich manganese-based cathode material, improve the specific surface area of ​​the lithium-rich manganese-based cathode material, facilitate the rapid insertion and extraction of lithium ions, increase the diffusion rate of lithium ions, and thus improve the rate performance of the lithium-rich manganese-based cathode material.

[0011] In one possible implementation, the particle size distribution Dv50 of the lithium-rich manganese-based cathode material satisfies: 4µm to 12µm. In the embodiments of this application, a suitable particle size of the lithium-rich manganese-based cathode material can improve the structural stability and power density of the lithium-rich manganese-based cathode material, and enhance its rate performance.

[0012] In one possible implementation, the particle size distribution Dv50 of the lithium-rich manganese-based cathode material satisfies: 4µm to 8µm. In the embodiments of this application, a better particle size distribution Dv50 of the lithium-rich manganese-based material can further improve the structural stability and power density of the lithium-rich manganese-based cathode material, thereby improving the rate performance of the lithium-rich manganese-based cathode material.

[0013] In one possible implementation, the compaction density of the lithium-rich manganese-based cathode material satisfies: 2.8 g / cm³. 3 ~3.13g / cm 3 By controlling the appropriate compaction density of the lithium-rich manganese-based cathode material in a lithium-ion battery cell, the lithium-ion battery cell can achieve a better energy density, thereby improving its rate performance.

[0014] Fourthly, a method for preparing a cathode material is provided, comprising: co-precipitating a transition metal salt, a complexing agent, and a surfactant to obtain a lithium-rich manganese-based cathode material precursor; wherein the complexing agent comprises a compound having carboxyl and hydroxyl groups, or the complexing agent comprises a compound having carboxyl and amino groups. The mass ratio A of the surfactant to the transition metal salt satisfies: 1:1000 ≤ A ≤ 1:20. The obtained lithium-rich manganese-based cathode material precursor is used to prepare a lithium-rich manganese-based cathode material with a morphology of spherical bodies formed by primary particle stacking and needle-like clusters formed by linearly arranged primary particles radially distributed on the surface of the spherical bodies.

[0015] In this embodiment, the complexing agent compound contains carboxyl and hydroxyl groups or carboxyl and amino groups, which can effectively complex transition metal ions, control crystal growth rate and the generation of new crystal nuclei. Furthermore, the complex has stable physicochemical properties and is not easily volatilized or decomposed, which is beneficial for the preparation of lithium-rich manganese-based cathode material precursors. In addition, the addition of an appropriate proportion of surfactant during the preparation process is beneficial for promoting radial grain growth and has a synergistic effect with the complexing agent, further promoting primary particle growth, improving the dispersion degree and production efficiency of lithium-rich manganese-based cathode material precursors, obtaining lithium-rich manganese-based cathode material precursors with radial morphology. Through the lithium-rich manganese-based cathode material precursors with radial morphology, lithium-rich manganese-based cathode materials with spherical bodies formed by primary particle stacking and needle-like clusters formed by linearly arranged primary particles radially distributed on the surface of the spherical bodies can be prepared, thereby improving the rate performance of lithium-ion battery cells.

[0016] In one possible implementation, the mass ratio A of the surfactant to the transition metal salt satisfies: 1:800 ≤ A ≤ 1:50. In the embodiments of this application, adding an appropriate proportion of surfactant during the preparation process is beneficial to promoting radial grain growth and working synergistically with the complexing agent to further promote primary particle growth, improve the dispersion degree and production efficiency of lithium-rich manganese-based cathode material precursors.

[0017] In one possible implementation, the concentration α of the complexing agent satisfies: 0.1 mol / L ≤ α ≤ 2 mol / L. Optionally, the concentration α of the complexing agent satisfies: 0.4 mol / L ≤ α ≤ 1.8 mol / L. In the embodiments of this application, by selecting an appropriate concentration of complexing agent, it is helpful to obtain a lithium-rich manganese-based cathode material precursor with radial morphology, uniform distribution, homogeneous composition, high compaction density, and regular morphology.

[0018] In one possible implementation, the surfactant includes at least one selected from sodium dodecyl sulfate (SDS), hexadecyltrimethylammonium bromide (CTAB), polyvinylpyrrolidone (PVP), and sodium dodecylbenzene sulfonate (SDBS). In the embodiments of this application, by selecting a suitable type of surfactant, it can synergistically work with the complexing agent to help promote primary particle growth and improve the dispersion of the cathode material precursor.

[0019] In one possible implementation, the complexing agent includes at least one of salicylates, citrates, ethylenediaminetetraacetic acid salts, tartrates, and gluconates. In the embodiments of this application, by selecting the above-mentioned compounds containing carboxyl and hydroxyl groups, or containing carboxyl and amino groups, as complexing agents, transition metal ions can be effectively complexed, controlling the crystal growth rate and the generation of new crystal nuclei. Furthermore, such complexes exhibit stable physicochemical properties, are not easily volatilized or decomposed, and have stable complexing ability, which is beneficial for the preparation of lithium-rich manganese-based cathode material precursors.

[0020] In one possible implementation, the transition metal salt includes: sulfate transition metal salts, nitrate transition metal salts, acetate transition metal salts, and chloride transition metal salts, wherein the transition metal includes one or more combinations of Ni, Co, Mn, Al, Cr, Fe, Nb, Zr, W, and Mg. In the embodiments of this application, by doping with suitable elements and controlling the appropriate element ratios, it is beneficial to improve the performance and structural stability of the cathode material precursor.

[0021] In one possible implementation, during the co-precipitation process, the pH in the reactor satisfies: 8 ≤ pH ≤ 12, the temperature T in the reactor satisfies: 25℃ ≤ T ≤ 50℃, and the rotational speed R of the reactor satisfies: 600 rpm ≤ R ≤ 1200 rpm. In the embodiments of this application, by controlling the parameters of the co-precipitation reaction process, it is helpful to obtain a cathode material precursor with high compaction density, uniform primary particles, and good sphericity.

[0022] In one possible implementation, the obtained lithium-rich manganese-based cathode material precursor satisfies one or more of the following conditions: median particle size B satisfies: 2μm≤B≤15μm, particle size distribution span SPAN satisfies: 0.5≤SPAN≤1.2, tap density C satisfies: 1.3g / cc≤C≤2.0g / cc, and specific surface area D satisfies: 15m² 2 / g≤D≤50m 2 / g. Optionally, the obtained lithium-rich manganese-based cathode material precursor satisfies one or more of the following conditions: median particle size B satisfies: 3μm≤B≤10μm, particle size distribution span SPAN satisfies: 0.5≤SPAN≤1.1, tap density C satisfies: 1.5g / cc≤C≤1.8g / cc, specific surface area D satisfies: 20m² / g. 2 / g≤D≤40m 2 / g. In the embodiments of this application, the synthesized lithium-rich manganese-based cathode material precursor has a regular morphology and a radial distribution inside, with suitable specific surface area, median particle size, tap density and particle size distribution range, thereby ensuring that the lithium-rich manganese-based cathode material prepared using this lithium-rich manganese-based cathode material precursor has high energy density and excellent cycle performance.

[0023] Fifthly, a battery is provided, comprising a lithium-ion battery cell according to the first aspect and any possible implementation thereof, and / or a lithium-ion battery cell obtained by the preparation method according to the second aspect and any possible implementation thereof.

[0024] Sixthly, an electrical device is provided, comprising the battery of the fifth aspect and any possible implementation thereof. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of a method for preparing a positive electrode material according to an embodiment of this application;

[0027] Figure 2 This is a scanning electron microscope image of positive electrode material particles according to an embodiment of this application;

[0028] Figure 3 This is a schematic diagram of a method for preparing a lithium-ion battery cell according to an embodiment of this application;

[0029] Figure 4 This is a schematic diagram of a lithium-ion battery cell according to an embodiment of this application;

[0030] Figure 5 This is a schematic diagram of a battery according to an embodiment of this application;

[0031] Figure 6 This is a schematic diagram of an electrical device according to an embodiment of this application;

[0032] Figure 7 This is a schematic diagram of another electrical device according to an embodiment of this application.

[0033] Reference numerals: 3: Lithium-ion battery cell; 31: Casing; 32: End cap assembly; 33: Electrode assembly; 34: Connecting member; 322: Electrode terminal; 331: Tab; 5: Battery; 6: Automobile; 7: Energy storage device. Detailed Implementation

[0034] The following detailed description of the lithium-ion battery cell, related preparation methods, battery, and power-consuming device of this application, with appropriate reference to the accompanying drawings, may omit unnecessary detailed descriptions. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided for the purpose of enabling those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0035] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0036] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0037] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0038] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0039] In recent years, rechargeable batteries have been widely used in power tools, electronic products, electric vehicles, aerospace, and other fields due to their high energy density and long service life, resulting in significant development. The development of battery technology requires consideration of various design factors, such as energy density, cycle life, capacity, and safety and reliability. In lithium-ion battery cells, lithium-rich manganese-based cathode materials have low ionic and electronic conductivity, leading to poor rate performance. Adjusting the radial morphology of lithium-rich manganese-based cathode materials can improve the rate performance of lithium-ion battery cells. However, the morphology of lithium-rich manganese-based cathode materials is usually inherited from their precursors. In existing technologies, the primary particles of hydroxide or carbonate precursors prepared by co-precipitation are mostly plate-like or granular, making it difficult to control the radial morphology of these precursor particles. This makes it difficult for lithium-rich manganese-based cathode materials to meet the requirements for radial morphology, thus failing to improve the rate performance of lithium-ion battery cells.

[0040] In some existing implementations, the morphology of the lithium-rich manganese-based cathode material precursor can be controlled by adjusting the ammonia concentration during the co-precipitation process to regulate the nucleation rate and primary particle growth. However, ammonia is unstable and easily decomposes during use, making reaction control difficult and affecting the complexation effect. This makes it difficult to improve the morphology of the lithium-rich manganese-based cathode material precursor in actual production, thus making it difficult for the lithium-rich manganese-based cathode material to meet the requirement of radial morphology and failing to improve the rate performance of lithium-ion battery cells.

[0041] Therefore, obtaining a lithium-ion battery cell with a radially morphological lithium-rich manganese-based cathode material and improving the rate performance of the lithium-ion battery cell is an urgent technical problem to be solved.

[0042] In view of this, one embodiment of this application provides a cathode material, which is a lithium-rich manganese-based cathode material. This lithium-rich manganese-based cathode material includes spherical bodies formed by the stacking of primary particles and needle-like clusters formed by the linear arrangement of primary particles, with the needle-like clusters radially distributed on the surface of the aforementioned spherical bodies. The diameter of the spherical bodies is 1µm to 5µm, and the length of the needle-like clusters is 1µm to 7µm. The lithium-rich manganese-based cathode material provided in this solution has a special radial morphology, consisting of spherical bodies formed by the stacking of primary particles and needle-like clusters radially distributed on the surface of the spherical bodies. By controlling the appropriate diameter of the spherical bodies and the length of the needle-like clusters, it is beneficial to improve the structural stability of the lithium-rich manganese-based cathode material, increase the specific surface area of ​​the lithium-rich manganese-based cathode material, facilitate the rapid insertion and extraction of lithium ions, improve the diffusion rate of lithium ions, and enhance the rate performance of the lithium-rich manganese-based cathode material, thereby improving the rate performance of lithium-ion battery cells. Among them, primary particles refer to smaller particles formed by chemical reactions of primary particles of the precursor of the lithium-rich manganese-based cathode material.

[0043] In the embodiments of this application, a single lithium-ion battery cell can refer to the smallest structural unit of a battery. Multiple lithium-ion battery cells can first be assembled into a battery module, and then the battery module can be assembled into a battery (battery pack); multiple lithium-ion battery cells can also be directly assembled into a battery.

[0044] In addition, the following description, with appropriate reference to the accompanying drawings, will illustrate the preparation method of the cathode material, the cathode material, the preparation method of the lithium-ion battery cell, the lithium-ion battery cell, the battery, and the power-consuming device of this application.

[0045] [Preparation methods for cathode materials]

[0046] In one embodiment of this application, a method for preparing a positive electrode material is provided.

[0047] Figure 1 This is a schematic diagram illustrating a method for preparing a cathode material according to an embodiment of this application. (Combined with...) Figure 1 As shown, the preparation method 1 of the positive electrode material may include the following steps.

[0048] S110, to obtain a complexing agent having carboxyl and hydroxyl groups, or having carboxyl and amino groups, wherein the mass ratio A of the surfactant to the transition metal salt is configured as 1:1000≤A≤1:20.

[0049] S120 is used to co-precipitate transition metal salts, complexing agents, and surfactants to obtain lithium-rich manganese-based cathode material precursors.

[0050] S130, using this lithium-rich manganese-based cathode material precursor to prepare a lithium-rich manganese-based cathode material with a morphology of spherical bodies formed by primary particle stacking and needle-like clusters formed by linearly arranged primary particles radially distributed on the surface of the spherical bodies.

[0051] Therefore, this application obtains a lithium-rich manganese-based cathode material precursor with a special radial morphology by adding a complexing agent containing compounds with carboxyl and hydroxyl groups, or compounds containing carboxyl and amino groups, during the preparation of the lithium-rich manganese-based cathode material precursor, and by co-precipitating the surfactant with a transition metal salt solution. The mass ratio A of the surfactant to the transition metal salt satisfies: 1:1000 ≤ A ≤ 1:20. This lithium-rich manganese-based cathode material precursor is used to prepare lithium-rich manganese-based cathode materials with a morphology of spherical bodies formed by primary particle stacking and needle-like clusters formed by radially distributed primary particles on the surface of the spherical bodies.

[0052] Specifically, the mass ratio of the surfactant to the transition metal salt can be 1:1000, 1:900, 1:800, 1:700, 1:600, 1:500, 1:400, 1:300, 1:200, 1:100, 1:20, or any value within the range of 1:1000≤A≤1:20.

[0053] In this embodiment, the complexing agent compound contains carboxyl and hydroxyl groups, or carboxyl and amino groups, which can effectively complex transition metal ions, control the crystal growth rate and new crystal nucleus generation of the lithium-rich manganese-based cathode material precursor, and the complexes are physicochemically stable, not easily volatilized or decomposed, which is beneficial for the preparation of the precursor. In addition, the addition of an appropriate proportion of surfactant during the preparation process is beneficial for promoting the radial growth of the lithium-rich manganese-based cathode material precursor crystals and has a synergistic effect with the complexing agent, further promoting the primary particle growth of the precursor, improving the dispersion degree of the lithium-rich manganese-based cathode material precursor and production efficiency. By obtaining a lithium-rich manganese-based cathode material precursor with a radial morphology, lithium-rich manganese-based cathode materials with spherical morphologies formed by primary particle stacking and needle-like clusters formed by linearly arranged primary particles radially distributed on the surface of the spherical morphologies can be prepared. This special radial morphology is beneficial to improving the structural stability of lithium-rich manganese-based cathode materials, increasing the specific surface area of ​​lithium-rich manganese-based cathode materials, facilitating the rapid insertion and extraction of lithium ions, improving the migration speed of lithium ions during cycling, enhancing the rate performance of lithium-rich manganese-based cathode materials, and thus improving the rate performance of lithium-ion battery cells.

[0054] In some embodiments, the surfactant includes at least one of sodium dodecyl sulfate (SDS), hexadecyltrimethylammonium bromide (CTAB), polyvinylpyrrolidone (PVP), and sodium dodecylbenzene sulfonate (SDBS), and the mass ratio A of the surfactant to the transition metal salt satisfies: 1:800 ≤ A ≤ 1:50.

[0055] Specifically, the mass ratio of surfactant to transition metal salt can be 1:800, 1:700, 1:600, 1:500, 1:400, 1:300, 1:200, 1:100, 1:50, or any value within the range of 1:800≤A≤1:50. In the embodiments of this application, by selecting appropriate types and proportions of surfactants, they can work synergistically with complexing agents to help promote the primary particle growth of lithium-rich manganese-based cathode material precursors and improve the dispersion degree of lithium-rich manganese-based cathode material precursors.

[0056] In some embodiments, the complexing agent includes at least one of salicylates, citrates, ethylenediaminetetraacetic acid salts, tartrates, and gluconates. In the embodiments of this application, by selecting the above-mentioned compounds containing carboxyl and hydroxyl groups, or containing carboxyl and amino groups, as complexing agents, transition metal ions can be effectively complexed, controlling the crystal growth rate and new crystal nucleus generation of the lithium-rich manganese-based cathode material precursor. Furthermore, such complexes are physically and chemically stable, not easily volatilized or decomposed, and have stable complexing ability, which is beneficial for the preparation of lithium-rich manganese-based cathode material precursors.

[0057] In some embodiments, the concentration α of the added complexing agent satisfies: 0.1 mol / L ≤ α ≤ 2 mol / L. Specifically, the concentration of the complexing agent can be 0.1 mol / L, 0.5 mol / L, 0.7 mol / L, 1 mol / L, 1.5 mol / L, 1.8 mol / L, 2 mol / L, or any value within the range of 0.1 mol / L ≤ α ≤ 2 mol / L.

[0058] Optionally, the concentration α of the added complexing agent satisfies the condition: 0.4 mol / L ≤ α ≤ 1.8 mol / L. Specifically, the concentration of the complexing agent can be 0.4 mol / L, 0.5 mol / L, 0.7 mol / L, 0.9 mol / L, 1 mol / L, 1.2 mol / L, 1.4 mol / L, 1.6 mol / L, 1.8 mol / L, or any value within the range of 0.4 mol / L ≤ α ≤ 1.8 mol / L.

[0059] In the embodiments of this application, by selecting an appropriate complexing agent concentration, it is helpful to obtain a lithium-rich manganese-based cathode material precursor with radial morphology, uniform distribution, homogeneous composition, high compaction density, and regular morphology.

[0060] In some embodiments, the transition metal salt includes: sulfate transition metal salts, nitrate transition metal salts, acetate transition metal salts, and chloride transition metal salts, wherein the transition metal includes one or more combinations of Ni, Co, Mn, Al, Cr, Fe, Nb, Zr, W, and Mg. In the embodiments of this application, by doping with suitable elements and controlling the appropriate element ratios, it is beneficial to improve the performance and structural stability of the lithium-rich manganese-based cathode precursor material.

[0061] In some embodiments, during the co-precipitation of the complexing agent, surfactant, and transition metal salt in the reactor, the pH in the reactor satisfies the condition: 8 ≤ pH ≤ 12. Specifically, the pH in the reactor can be 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, or 12, or any value within the range of 8 ≤ pH ≤ 12. The temperature T in the reactor satisfies the condition: 25℃ ≤ T ≤ 50℃. Specifically, the temperature in the reactor can be 25℃, 28℃, 30℃, 33℃, 35℃, 37℃, 40℃, 42℃, 45℃, 49℃, or 50℃, or any value within the range of 25℃ ≤ T ≤ 50℃. The rotational speed R of the reactor satisfies the condition: 600 rpm ≤ R ≤ 1200 rpm. Specifically, the rotational speed can be 600 rpm, 650 rpm, 680 rpm, 700 rpm, 750 rpm, 800 rpm, 850 rpm, 900 rpm, 950 rpm, 1000 rpm, 1050 rpm, 1100 rpm, 1150 rpm, or 1200 rpm, or any value within the range of 600 rpm ≤ R ≤ 1200 rpm. In the embodiments of this application, controlling the parameters of the co-precipitation reaction process helps to obtain a lithium-rich manganese-based cathode material precursor with high compaction density, uniform primary particles, and good sphericity.

[0062] Preferably, during the co-precipitation process, the pH in the reactor satisfies: 8 ≤ pH ≤ 10. Specifically, the pH in the reactor can be 8, 8.3, 8.6, 9, 9.3, 9.5, 9.7, or 10, or any value within the range of 8 ≤ pH ≤ 10. The temperature T in the reactor is 30°C, and the rotation speed R of the reactor is 800 rpm. In the embodiments of this application, by controlling the preferred parameters of the co-precipitation reaction process, it is helpful to further obtain a lithium-rich manganese-based cathode material precursor with high compaction density, uniform primary particles, and good sphericity.

[0063] In some embodiments, the molecular formula of the lithium-rich manganese-based cathode material precursor prepared is Ni a Co b Mn c M 1-a-b-c (OH)2 or Ni a Cob Mn c M 1-a-b-c CO3, where M is any one or a combination of more than one of Al, Cr, Fe, Nb, Zr, W, Mg, and the molecular formula satisfies: a + b + c ≤ 1, 0 < b < a < c, 0 < c < 1. In the embodiments of the present application, the synthesized lithium-rich manganese-based cathode material precursor is a high-manganese, low-cobalt, and low-nickel hydroxide or carbonate precursor, which is beneficial to reducing costs. By doping appropriate elements and appropriate element ratios, it is beneficial to improve the stability of the material structure.

[0064] Furthermore, the molecular formula satisfies: 0 < b < 0.12 < a < 0.5 < c < 1. In the embodiments of the present application, by controlling the ratios between various elements, it is beneficial to improve the stability of the structure of the lithium-rich manganese-based cathode material precursor.

[0065] In some embodiments, the molecular formula of the prepared lithium-rich manganese-based cathode material is Li[Li m Ni a Co b Mn c M d O 2-e R e of the material, M includes at least one of Zr, Al, Cu, Mg, Zn, Ti, V, Ga, Sn, Ge, B, Ta, Mo, W, Nb, Sb, La; R includes at least one of F, S, Cl, Br, P, where m + a + b + c + d = 1, 0 < m < 1, 0 < a < 0.5, 0 ≤ b < 0.5, 0.5 ≤ c < 1, 0 ≤ d < 0.2, 0 ≤ e < 0.2. The lithium-rich manganese-based cathode material includes one or more of nickel element, cobalt element, and manganese element. Among them, the molar proportion of the manganese element in all metal elements except lithium is greater than or equal to 50%. In the embodiments of the present application, the synthesized lithium-rich manganese-based cathode material is beneficial to improving the performance of the material by doping appropriate elements and appropriate element ratios.

[0066] In some embodiments, the prepared lithium-rich manganese-based cathode material precursor satisfies one or more of the following conditions: the median particle size B satisfies 2μm≤B≤15μm. Specifically, the median particle size of the lithium-rich manganese-based cathode material precursor can be 2μm, 3μm, 5μm, 7μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, or any value within the range of 2μm≤B≤15μm. The lithium-rich manganese-based particle size distribution span SPAN satisfies 0.5≤SPAN≤1.2. Specifically, the particle size distribution span of the lithium-rich manganese-based cathode material precursor can be 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, or any value within the range of 0.5≤SPAN≤1.2. The tap density C satisfies 1.3 g / cc ≤ C ≤ 2.0 g / cc. Specifically, the tap density of the lithium-rich manganese-based cathode material precursor can be 1.3 g / cc, 1.4 g / cc, 1.5 g / cc, 1.6 g / cc, 1.7 g / cc, 1.8 g / cc, 1.9 g / cc, 2.0 g / cc, or any value within the range of 1.3 g / cc ≤ C ≤ 2.0 g / cc. The specific surface area D satisfies 15 m² / s². 2 / g≤D≤50m 2 / g, specifically, the specific surface area of ​​the lithium-rich manganese-based cathode material precursor can be 15m². 2 / g、19m 2 / g、20m 2 / g、25m 2 / g、28m 2 / g、30m 2 / g、33m 2 / g、36m 2 / g、40m 2 / g、43m 2 / g、47m 2 / g, 50m 2 / g, or its value at 15m 2 / g≤D≤50m 2 Any value within the range / g.

[0067] Optionally, the prepared lithium-rich manganese-based cathode material precursor satisfies one or more of the following conditions: the median particle size B satisfies 3μm≤B≤10μm. Specifically, the median particle size of the cathode material precursor can be 3μm, 5μm, 5μm, 6μm, 7μm, 9μm, 10μm, or any value within the range of 3μm≤B≤10μm. The particle size distribution span SPAN satisfies 0.5≤SPAN≤1.1. Specifically, the particle size distribution span of the cathode material precursor can be 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, or any value within the range of 0.5≤SPAN≤1.1. The tap density C satisfies 1.5 g / cc ≤ C ≤ 1.8 g / cc. Specifically, the tap density of the cathode material precursor can be 1.5 g / cc, 1.6 g / cc, 1.7 g / cc, 1.8 g / cc, or any value within the range of 1.5 g / cc ≤ C ≤ 1.8 g / cc. The specific surface area D satisfies 20 m² / s². 2 / g≤D≤40m 2 / g, specifically, the specific surface area of ​​the cathode material precursor can be 20m². 2 / g、23m 2 / g、25m 2 / g、28m 2 / g、30m 2 / g、32m 2 / g、35m 2 / g、38m 2 / g、40m 2 / g, or a value of 20m 2 / g≤D≤40m 2 Any value within the range / g.

[0068] In the above embodiments, the synthesized lithium-rich manganese-based cathode material precursor has a regular morphology and radial distribution, with suitable specific surface area, median particle size, tap density and particle size distribution span, thereby ensuring that the lithium-rich manganese-based cathode material has high energy density and excellent cycle performance, thereby improving the rate performance of lithium-ion battery cells.

[0069] [Cathode Material]

[0070] A lithium-rich manganese-based cathode material was obtained through the cathode material preparation method described in the above embodiments.

[0071] Figure 2 The images shown are scanning electron microscope (SEM) images of the lithium-rich manganese-based cathode material in some embodiments of this application.

[0072] like Figure 2As shown, the lithium-rich manganese-based cathode material provided in this embodiment includes spherical bodies formed by the stacking of primary particles and needle-like clusters formed by the linear arrangement of primary particles. The primary particles refer to smaller particles formed by a chemical reaction of the primary particles of the precursor of the lithium-rich manganese-based cathode material. The aforementioned needle-like clusters are radially distributed on the surface of the spherical bodies formed by the stacking of primary particles. The diameter of the spherical bodies is between 1 μm and 5 μm. Specifically, the diameter of the spherical bodies can be 1 μm, 1.3 μm, 1.5 μm, 1.8 μm, 2 μm, 2.2 μm, 2.5 μm, 2.7 μm, 2.9 μm, 3 μm, 3.2 μm, 3.5 μm, 3.8 μm, 4 μm, 4.2 μm, 4.5 μm, 4.7 μm, 4.9 μm, or 5 μm, or any value within the range of 1 μm to 5 μm. The length of the needle-like clusters is between 1 μm and 7 μm. Specifically, the length of the needle-like clusters can be 1um, 1.3um, 1.5um, 1.8um, 2um, 2.2um, 2.5um, 2.7um, 3um, 3.2um, 3.5um, 3.8um, 4um, 4.2um, 4.5um, 4.9um, 5um, 5.3um, 5.6um, 6um, 6.2um, 6.7um, or 7um, or any value within the range of 1um to 7um.

[0073] In the above embodiments, the lithium-rich manganese-based cathode material has a special radial morphology. By controlling the appropriate spherical diameter and needle-like cluster length, it is beneficial to improve the stability of the particle structure, improve the specific surface area of ​​the particles, facilitate the rapid insertion and extraction of lithium ions, increase the diffusion rate of lithium ions, improve the rate performance of the lithium-rich manganese-based cathode material, and thus improve the rate performance of lithium-ion battery cells.

[0074] In some embodiments, the number of needle-like clusters on each surface of the sphere is 10. 4 ~10 8 Specifically, the number of needle-like clusters on the surface of each spherical body can be 10. 4 10 5 10 6 10 7 10 8 or its value is in 10 4 ~10 8 Any value within the range. In the embodiments of this application, increasing the number of needle-like clusters can improve structural stability, increase the specific surface area of ​​particles, increase the diffusion rate of lithium ions, and thus improve the rate performance of lithium-ion battery cells.

[0075] In some embodiments, the particle size distribution Dv50 of the lithium-rich manganese-based cathode material satisfies 4 μm to 12 μm. Specifically, the particle size distribution Dv50 of the lithium-rich manganese-based cathode material can be 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, 8.5 μm, 9 μm, 9.5 μm, 10 μm, 10.5 μm, 11 μm, 11.5 μm, or 12 μm, or any value within the range of 4 μm to 12 μm. Optionally, the particle size distribution Dv50 of the lithium-rich manganese-based cathode material satisfies 4 μm to 8 μm. Specifically, the particle size distribution Dv50 of the lithium-rich manganese-based cathode material can be 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, 7.5 μm, or 8 μm, or any value within the range of 4 μm to 8 μm. In the embodiments of this application, a suitable lithium-rich manganese-based cathode material particle size distribution Dv50 improves the structural stability and power density of the lithium-rich manganese-based cathode material, thereby enhancing the rate performance of lithium-ion battery cells.

[0076] In some embodiments, the compaction density of the lithium-rich manganese-based cathode material satisfies: 2.8 g / cm³ 3 ~3.13g / cm 3 Specifically, the compaction density of lithium-rich manganese-based cathode materials can be 2.8 g / cm³. 3 2.9g / cm 3 3.0g / cm 3 3.13 g / cm 3 Or its value is 2.8 g / cm³ 3 ~3.13g / cm 3 Any value within the range. By controlling the compaction density of the lithium-rich manganese-based cathode material in the lithium-ion battery cell, the lithium-ion battery cell can have a better energy density, thereby improving the rate performance of the lithium-ion battery cell.

[0077] [Preparation methods for lithium-ion battery cells]

[0078] In one embodiment of this application, a method for preparing a lithium-ion battery cell is provided.

[0079] Figure 3 This is a schematic diagram illustrating a method for preparing a lithium-ion battery cell according to an embodiment of this application. (Combined with...) Figure 3 As shown, the preparation method 2 of a lithium-ion battery cell may include the following steps.

[0080] S210, to obtain a complexing agent having carboxyl and hydroxyl groups, or having carboxyl and amino groups, wherein the mass ratio A of the surfactant to the transition metal salt is configured as 1:1000≤A≤1:20.

[0081] S220 is used to co-precipitate transition metal salts, complexing agents, and surfactants to obtain lithium-rich manganese-based cathode material precursors.

[0082] S230 uses this lithium-rich manganese-based cathode material precursor to prepare a lithium-rich manganese-based cathode material with a morphology of spherical bodies formed by primary particle stacking and needle-like clusters formed by linearly arranged primary particles radially distributed on the surface of the spherical bodies.

[0083] S240 involves coating a slurry containing lithium-rich manganese-based cathode material onto the surface of a cathode current collector to prepare a cathode electrode sheet.

[0084] S250 involves assembling the prepared positive electrode sheet, separator, and negative electrode sheet in sequence to prepare an electrode assembly.

[0085] S260 uses the prepared electrode assembly to prepare lithium-ion battery cells.

[0086] This application describes a process for preparing a lithium-rich manganese-based cathode material precursor. This involves adding a complexing agent containing carboxyl and hydroxyl groups, or a compound containing carboxyl and amino groups, during the preparation of the precursor. A surfactant is then co-precipitated with a transition metal salt solution to obtain a lithium-rich manganese-based cathode material precursor with a unique radial morphology. The mass ratio A of the surfactant to the transition metal salt satisfies the condition: 1:1000 ≤ A ≤ 1:20. This lithium-rich manganese-based cathode material precursor is used to prepare lithium-rich manganese-based cathode materials with spherical morphologies formed by primary particle stacking and needle-like clusters radially distributed on the surface of the spherical particles. An electrode assembly is prepared by sequentially combining a positive electrode sheet containing this lithium-rich manganese-based cathode material with a separator and a negative electrode sheet. This electrode assembly is then used to prepare lithium-ion battery cells.

[0087] Specifically, the mass ratio of the surfactant to the transition metal salt can be 1:1000, 1:900, 1:800, 1:700, 1:600, 1:500, 1:400, 1:300, 1:200, 1:100, 1:20, or any value within the range of 1:1000≤A≤1:20.

[0088] In this embodiment, the complexing agent compound contains carboxyl and hydroxyl groups, or carboxyl and amino groups, which can effectively complex transition metal ions, control the crystal growth rate and new crystal nucleus generation of the lithium-rich manganese-based cathode material precursor, and the complexes are physicochemically stable, not easily volatilized or decomposed, which is beneficial for the preparation of the precursor. In addition, the addition of an appropriate proportion of surfactant during the preparation process is beneficial for promoting the radial growth of the lithium-rich manganese-based cathode material precursor crystals and has a synergistic effect with the complexing agent, further promoting the primary particle growth of the precursor, improving the dispersion degree of the lithium-rich manganese-based cathode material precursor and production efficiency. By obtaining a lithium-rich manganese-based cathode material precursor with a radial morphology, lithium-rich manganese-based cathode materials with spherical morphologies formed by primary particle stacking and needle-like clusters formed by linearly arranged primary particles radially distributed on the surface of the spherical morphologies can be prepared. This special radial morphology is beneficial to improving the structural stability of lithium-rich manganese-based cathode materials, increasing the specific surface area of ​​lithium-rich manganese-based cathode materials, facilitating the rapid insertion and extraction of lithium ions, improving the migration speed of lithium ions during cycling, and enhancing the rate performance of lithium-rich manganese-based cathode materials, thereby improving the rate performance of lithium-ion battery cells.

[0089] [Lithium-ion battery cell]

[0090] A lithium-ion battery cell was obtained through the preparation method of the lithium-ion battery cell in the above embodiments.

[0091] The lithium-ion battery cell includes the lithium-rich manganese-based cathode material described in the above embodiments. This lithium-rich manganese-based cathode material comprises spherical bodies formed by the stacking of primary particles and needle-like clusters formed by the linear arrangement of primary particles. The needle-like clusters are radially distributed on the surface of the spherical bodies. The diameter of the spherical bodies is between 1 μm and 5 μm. Specifically, the diameter of the spherical bodies can be 1 μm, 1.3 μm, 1.5 μm, 1.8 μm, 2 μm, 2.2 μm, 2.5 μm, 2.7 μm, 2.9 μm, 3 μm, 3.2 μm, 3.5 μm, 3.8 μm, 4 μm, 4.2 μm, 4.5 μm, 4.7 μm, 4.9 μm, or 5 μm, or any value within the range of 1 μm to 5 μm. The length of the needle-like clusters is between 1 μm and 7 μm. Specifically, the length of the needle-like clusters can be 1um, 1.3um, 1.5um, 1.8um, 2um, 2.2um, 2.5um, 2.7um, 3um, 3.2um, 3.5um, 3.8um, 4um, 4.2um, 4.5um, 4.9um, 5um, 5.3um, 5.6um, 6um, 6.2um, 6.7um, or 7um, or any value within the range of 1um to 7um.

[0092] In the above embodiments, the lithium-rich manganese-based cathode material has a special morphology. By controlling the appropriate spherical diameter and needle-like cluster length, it is beneficial to improve the stability of the particle structure, improve the specific surface area of ​​the particles, facilitate the rapid insertion and extraction of lithium ions, and increase the diffusion rate of lithium ions, thereby improving the power density of the battery and thus improving the rate performance of the lithium-ion battery cell.

[0093] The embodiments of this application do not impose any particular restrictions on the shape of the lithium-ion battery cell; it can be cylindrical, square, or any other arbitrary shape.

[0094] Figure 4 This is a schematic diagram of a lithium-ion battery cell according to an embodiment of this application. For example, as... Figure 4 As shown, the lithium-ion battery cell 3 is a square lithium-ion battery cell. The lithium-ion battery cell 3 includes a housing 31, an end cap assembly 32, and an electrode assembly 33 disposed in the housing 31.

[0095] The electrode assembly 33 can be made from a positive electrode, a negative electrode, and a separator through a winding process or a stacking process.

[0096] End cap assembly 32 includes electrode terminals 322, such as Figure 4 As shown, the end cap assembly 32 includes two electrode terminals 322, one of which is a positive electrode terminal and the other is a negative electrode terminal.

[0097] The lithium-ion battery cell 3 also includes a connecting member 34, which is used to connect the tabs 331 and the electrode terminals 322 of the electrode assembly 33.

[0098] In some embodiments, lithium-ion battery cells can be assembled into battery modules. The number of lithium-ion battery cells contained in a battery module can be one or more, and the specific number can be selected by those skilled in the art according to the application and capacity of the battery module.

[0099] [Positive electrode plate]

[0100] The positive electrode includes a positive current collector and a positive electrode film layer disposed on at least one surface of the positive current collector, the positive electrode film layer including a positive active material. As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0101] In some embodiments, the positive current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. The composite current collector may include a polymer substrate and a metal layer formed on at least one surface of the polymer substrate. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0102] In some embodiments, the positive electrode active material may be a lithium-rich manganese-based positive electrode material with a special radial morphology of spherical bodies formed by primary particle stacking and needle-like clusters of primary particles radially distributed on the surface of the spherical bodies, such as Li 1.144 Ni 0.258 Co 0.055 Mn 0.543 O2.

[0103] In this lithium-rich manganese-based cathode material, the diameter of the spherical particles ranges from 1 μm to 5 μm, the length of the needle-like clusters ranges from 1 μm to 7 μm, and the number of needle-like clusters on the surface of the spherical particles is 10. 4 ~10 8 This improves the stability of the particle structure, increases the specific surface area of ​​the particles, facilitates the rapid insertion and extraction of lithium ions, and increases the diffusion rate of lithium ions, thereby improving the power density of the battery and ultimately enhancing the rate performance of the lithium-ion battery cell.

[0104] The particle size distribution Dv50 of the lithium-rich manganese-based cathode material satisfies: 4µm~12µm; optionally, the particle size distribution Dv50 of the lithium-rich manganese-based cathode material satisfies: 4µm~8µm. The compaction density of the lithium-rich manganese-based cathode material satisfies: 2.8 g / cm³. 3 ~3.13g / cm 3 .

[0105] In some embodiments, the positive electrode film layer may optionally include a binder. As an example, the binder may include at least one selected from polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resin.

[0106] In some embodiments, the positive electrode film may optionally include a conductive agent. As an example, the conductive agent may include at least one selected from superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0107] In some embodiments, the positive electrode sheet can be prepared by dispersing the above-mentioned components for preparing the positive electrode sheet, such as lithium-rich manganese-based positive electrode material, additives, conductive agents, binders and any other components, in a solvent (e.g., N-methylpyrrolidone) to form a positive electrode slurry; coating the positive electrode slurry onto a positive electrode current collector, and then obtaining the positive electrode sheet after drying, cold pressing and other processes.

[0108] [Negative electrode plate]

[0109] One embodiment of this application provides a negative electrode sheet comprising a negative current collector and a layer of negative active material disposed on the negative current collector.

[0110] The negative electrode current collector can be a metal foil or a composite negative electrode current collector. The negative electrode current collector can be copper foil. Composite negative electrode current collectors can be formed by depositing metallic materials (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) onto a polymer substrate (such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0111] The negative electrode active material layer includes a negative electrode active material. The negative electrode active material can be any negative electrode active material known in the art for use in batteries. As an example, the negative electrode active material may include one or more of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. The silicon-based material may be selected from one or more of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from one or more of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0112] The negative electrode active material layer may optionally include a binder. As an example, the binder may include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), styrene-butadiene rubber, carboxymethyl cellulose, PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resins.

[0113] The negative electrode active material layer may optionally include a conductive agent. The conductive agent may be selected from one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0114] [Electrolytes]

[0115] The electrolyte acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. For example, the electrolyte can be liquid, gel-like, or entirely solid.

[0116] In some embodiments, the electrolyte is an electrolyte solution. The electrolyte solution includes an electrolyte salt and a solvent.

[0117] Electrolyte salts may include one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0118] Solvents may include one or more of the following: ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone.

[0119] The electrolyte may also optionally include negative electrode film-forming additives, positive electrode film-forming additives, and performance additives that can improve certain battery performance, such as performance additives that improve battery overcharge performance, battery high temperature or low temperature performance, etc.

[0120] [Isolation Component]

[0121] The separator is used to separate the positive electrode and the negative electrode. This application does not impose any particular limitation on the type of separator; any known porous membrane with good chemical and mechanical stability can be selected.

[0122] The material of the separator can be selected from one or more of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film; there are no particular restrictions. When the separator is a multi-layer composite film, the materials of each layer can be the same or different; there are no particular restrictions.

[0123] Positive electrode, negative electrode and separator can be made into electrode assembly by winding process or stacking process.

[0124] [Battery]

[0125] This application provides a battery, including the lithium-ion battery cell described in the above embodiments. The lithium-ion battery cell can be a lithium-ion battery cell after formation and aging processes. Figure 5 This is a schematic diagram of a battery according to an embodiment of this application. Figure 5 As shown, battery 5 may include multiple lithium-ion battery cells (not shown in the figure).

[0126] Lithium-ion battery cells can be directly assembled into battery 5, or they can be first assembled into battery modules, and then multiple battery modules can be assembled into battery 5.

[0127] [Electrical appliances]

[0128] This application provides an electrical device, including the battery described in the above embodiments.

[0129] In some embodiments, the electrical device includes an energy storage device or a truck. Energy storage devices and trucks have high requirements for the lifespan and long-term cycle performance of lithium-ion battery cells; using lithium-ion battery cells in these electrical devices can improve their lifespan.

[0130] Electrical devices can also be lighting devices, spacecraft, etc., and the embodiments of this application include, but are not limited to, these.

[0131] Figure 6 This is a schematic diagram of an electrical device according to an embodiment of this application. Figure 6 As shown, this application provides an electrical device for a vehicle 6. As one example, the battery in the vehicle 6 can be swapped using a battery swapping device to replace a low-charge battery with a fully charged one. As another example, the battery in the vehicle 6 can be charged using a charging device (e.g., a charging station).

[0132] Figure 7 This is a schematic diagram of an electrical device according to an embodiment of this application. Figure 7 As shown, this application provides an electrical device, which is an energy storage device 7, and the energy storage device 7 may include multiple batteries 5. The energy storage device 7 can be applied to a power storage station to store and release electrical energy.

[0133] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0134] [Example]

[0135] Example 1

[0136] [Preparation of lithium-ion battery cells]

[0137] (1) Preparation of positive electrode active material:

[0138] Prepare a 2.5 mol / L solution of transition metal sulfate (TM) with a Ni:Co:Mn molar ratio of 30:06:64, and add sodium dodecyl sulfate (SDS) at a mass ratio of 0.8:100 to the transition metal salt. This solution is labeled as solution A. Prepare a 0.75 mol / L solution of sodium salicylate (as a complexing agent) and label it as solution B. Prepare a 5 mol / L solution of sodium hydroxide and label it as solution C. A certain amount of sodium salicylate and sodium hydroxide solution was added to the reactor beforehand to adjust the pH to approximately 8.5. Solutions A, B, and C were then pumped together into the reactor containing a nitrogen atmosphere. The pH was controlled at 9–10, the rotation speed at 800 r / min, and the temperature at 30℃ for 24 h. After the reaction was completed, the mixture was aged for 12 h, and the precipitate was collected. Impurities in the precursor were washed away with deionized water, and the precipitate was dried in an oven at 100–150℃ for 12 h to obtain a precursor material with a Dv50 of 7.5 μm, a radially distributed primary particle size, and no obvious agglomeration. A certain mass of the precursor was weighed and lithium was prepared according to a Li:TM ratio of 1.35:1, using lithium hydroxide as the lithium source. The weighed precursor and lithium source were mixed evenly in an agate mortar, collected in a corundum crucible, and placed in a muffle furnace. The temperature was controlled at 500℃ for 5 h, and then increased to 900℃ for 12 h, with a heating rate of 3℃ / min. After being allowed to cool naturally to room temperature, the material was removed, resulting in a lithium-rich manganese-based cathode material (Li) with a radial morphology. 1.144 Ni 0.258 Co 0.055 Mn 0.543 O2).

[0139] (2) Preparation of the positive electrode sheet:

[0140] The prepared lithium-rich manganese-based cathode material (Li 1.144 Ni 0.258 Co 0.055 Mn 0.543 O2), acetylene black, and PVDF are mixed uniformly in a mass ratio of 8:1:1 and coated on both sides of the outer surface of the positive electrode current collector. After coating, the electrode is dried in a long oven, then rolled and then die-cut to obtain the positive electrode sheet.

[0141] (3) Preparation of negative electrode sheet:

[0142] Graphite, conductive carbon, and sodium carboxymethyl cellulose were mixed uniformly in a mass ratio of 95:2:3. Deionized water was added and the mixture was evenly dispersed to obtain a homogeneous slurry. The slurry was then uniformly coated onto copper foil and dried. The negative electrode sheet was then produced by rolling and die cutting.

[0143] (4) Separating membrane:

[0144] The diaphragm is made of PE film (polyethylene film).

[0145] (5) Preparation of electrolyte:

[0146] Ethylene carbonate, diethyl carbonate, and dimethyl carbonate were mixed in a volume ratio of 1:1:1, and 1 mol / L LiPF6 was dissolved in the above solution to prepare an electrolyte.

[0147] (6) Preparation of lithium-ion batteries:

[0148] The batteries are assembled in an argon-filled glove box, following the order of positive electrode, separator, negative electrode, and nickel mesh.

[0149] Example 2

[0150] The difference between Example 2 and Example 1 is that the concentration of the complexing agent is different.

[0151] Example 3

[0152] The difference between Example 3 and Example 1 is that the type of surfactant and the mass ratio of surfactant to transition metal salt are different.

[0153] Example 4

[0154] The difference between Example 4 and Example 1 is that the complexing agent, the surfactant, and the mass ratio of surfactant to transition metal salt are different.

[0155] Example 5

[0156] The difference between Example 5 and Example 1 is that the type and concentration of the complexing agent are different, and the mass ratio of the surfactant to the transition metal salt is different.

[0157] Example 6

[0158] The difference between Example 6 and Example 1 is that the type and concentration of the complexing agent are different, and the mass ratio of the surfactant to the transition metal salt is different.

[0159] Comparative Example 1

[0160] The difference between Comparative Example 1 and Example 1 is that no complexing agent and surfactant were added.

[0161] Comparative Example 2

[0162] The difference between Comparative Example 2 and Example 1 is that no complexing agent was added.

[0163] The lithium-ion battery cells of Examples 2-6 and Comparative Examples 1-2 are prepared using methods similar to those of the lithium-ion battery cell of Example 1, but the composition of the relevant components and product parameters have been adjusted. The different product parameters are detailed in Table 1.

[0164] Table 1. Specific parameters of Examples 1-6 and Comparative Examples 1-2

[0165]

[0166] The cathode materials of each embodiment and comparative example were prepared using the above-mentioned cathode material precursors, and various parameters were measured. The results are shown in Table 2 below.

[0167] Table 2. Specific parameters of the cathode materials prepared in Examples 1-6 and Comparative Examples 1-2

[0168]

[0169]

[0170] [Choose-cell cycle performance test]

[0171] After formation, the lithium-ion battery cells are charged at 0.1C (1C = 230mAh) to 4.6V under a voltage range of 2.3–4.6V. Then, they are charged at a constant voltage of 4.6V until the current is ≤0.05mA, and allowed to stand for 2 minutes. The charge capacity at this point is recorded as C0. Next, the cells are discharged at 0.1C to 2.3V. The discharge capacity at this point is the initial specific capacity, recorded as D0. The initial efficiency is calculated as D0 / C0*100%. Afterward, 100 charge-discharge cycles are performed at 0.33C, and the energy retention rate is calculated.

[0172] Lithium-ion battery cells for each embodiment and comparative example were prepared according to the above method, and various performance parameters were measured. The results are shown in Table 3 below.

[0173] Table 3 Test results of Examples 1-6 and Comparative Examples 1-2

[0174]

[0175] In conjunction with Example 1 and Comparative Example 1,

[0176] Example 1 involved adding a 0.75 mol / L sodium salicylate complexing agent, a 2.5 mol / L transition metal sulfate solution, and sodium dodecyl sulfate (SDS) surfactant at a mass ratio of 0.8:100 to the transition metal sulfate solution, to co-precipitate and obtain the cathode material precursor Ni. 0.30 Co 0.06 Mn 0.64 (OH)2, and Li, a lithium-rich manganese-based cathode material, was prepared using this precursor. 1.144 Ni 0.258 Co 0.055 Mn 0.543O2. Compared to the precursor obtained without complexing agents and surfactants in Comparative Example 1, and the lithium-rich manganese-based cathode material obtained from this precursor, the lithium-rich manganese-based cathode material in Example 1 contains spherical bodies formed by primary particle stacking and needle-like clusters formed by primary particles arranged linearly. The diameter of the spherical bodies is 3.7 μm and the length of the needle-like clusters is 1.8 μm. At this spherical body diameter and needle-like cluster length, it is beneficial to improve the stability of the cathode material particle structure, improve the specific surface area of ​​the cathode material particles, facilitate the rapid insertion and extraction of lithium ions, and increase the diffusion rate of lithium ions. As a result, the prepared lithium-rich manganese-based cathode material has a higher compaction density, higher energy density, higher first-time efficiency in charge-discharge tests, higher 0.33C discharge specific capacity, and better energy retention rate after 100 cycles, thus improving the rate performance of lithium-ion battery cells.

[0177] In conjunction with Example 1 and Comparative Examples 1-2,

[0178] Comparative Example 2 was prepared by adding a 2.5 mol / L solution of a transition metal sulfate and sodium dodecyl sulfate (SDS) at a mass ratio of 0.8:100 to the transition metal sulfate, and co-precipitating to obtain the cathode material precursor Ni. 0.30 Co 0.06 Mn 0.64 (OH)2, and Li, a lithium-rich manganese-based cathode material, was prepared using this precursor. 1.144 Ni 0.258 Co 0.055 Mn 0.543 O2. Compared to the precursor obtained without complexing agents and surfactants in Comparative Example 1, and the lithium-rich manganese-based cathode material obtained from this precursor, the lithium-rich manganese-based cathode material in Comparative Example 2 has a higher compaction density, higher energy density, higher first-time efficiency in charge-discharge tests, a higher 0.33C discharge specific capacity, and better energy retention after 100 cycles. The addition of surfactants improves the rate performance of lithium-ion battery cells.

[0179] Example 1 involved adding a 0.75 mol / L sodium salicylate complexing agent, a 2.5 mol / L transition metal sulfate solution, and sodium dodecyl sulfate (SDS) surfactant at a mass ratio of 0.8:100 to the transition metal sulfate solution, to co-precipitate and obtain the cathode material precursor Ni. 0.30 Co 0.06 Mn 0.64 (OH)2, and Li, a lithium-rich manganese-based cathode material, was prepared using this precursor. 1.144 Ni 0.258 Co 0.055 Mn 0.543O2. Compared to the precursor obtained without a complexing agent in Comparative Example 2, and the lithium-rich manganese-based cathode material obtained from this precursor, the lithium-rich manganese-based cathode material in Example 1 contains spherical bodies formed by primary particle stacking and needle-like clusters formed by primary particles arranged linearly. The diameter of the spherical bodies is 3.7 μm and the length of the needle-like clusters is 1.8 μm. At this spherical body diameter and needle-like cluster length, it is beneficial to improve the stability of the cathode material particle structure, improve the specific surface area of ​​the cathode material particles, facilitate the rapid insertion and extraction of lithium ions, and increase the diffusion rate of lithium ions. As a result, the prepared lithium-rich manganese-based cathode material has a higher compaction density and higher energy density than the lithium-rich manganese-based cathode materials in Comparative Examples 1 and 2. It also has a higher first-time efficiency in charge-discharge tests, a higher 0.33C discharge specific capacity, and better energy retention after 100 cycles, thus improving the rate performance of lithium-ion battery cells.

[0180] In conjunction with Example 2 and Comparative Examples 1-2,

[0181] Example 2 involved adding a 1 mol / L sodium salicylate complexing agent, a 2.5 mol / L transition metal sulfate solution, and sodium dodecyl sulfate (SDS) surfactant at a mass ratio of 0.8:100 to the transition metal sulfate solution, to co-precipitate and obtain the cathode material precursor Ni. 0.30 Co 0.06 Mn 0.64 (OH)2, and Li, a lithium-rich manganese-based cathode material, was prepared using this precursor. 1.144 Ni 0.258 Co 0.055 Mn 0.543 O2. Compared to the precursor obtained without the complexing agent in Comparative Example 2, and the lithium-rich manganese-based cathode material obtained from this precursor, and compared to the precursor obtained without the complexing agent and surfactant in Comparative Example 1, and the lithium-rich manganese-based cathode material obtained from this precursor, the lithium-rich manganese-based cathode material in Example 2 contains spherical bodies formed by primary particle aggregation and needle-like clusters formed by primary particles arranged linearly. The diameter of the spherical bodies is 4.2 μm and the length of the needle-like clusters is 2.2 μm. The diameter of the spherical bodies and the length of the needle-like clusters are... The increased cluster length is beneficial for improving the stability of the cathode material particle structure, increasing the specific surface area of ​​the cathode material particles, facilitating the rapid insertion and extraction of lithium ions, and increasing the diffusion rate of lithium ions. As a result, the prepared lithium-rich manganese-based cathode material has a higher compaction density and energy density compared to the lithium-rich manganese-based cathode materials in Comparative Examples 1 and 2. It also has a higher first-time efficiency in charge-discharge tests, a higher 0.33C discharge specific capacity, and better energy retention after 100 cycles, thus improving the rate performance of lithium-ion battery cells.

[0182] In conjunction with Example 3 and Comparative Examples 1-2,

[0183] Example 3 involved adding a 0.75 mol / L sodium salicylate complexing agent, a 2.5 mol / L transition metal sulfate solution, and a cetyltrimethylammonium bromide (CTAB) surfactant at a mass ratio of 0.6:100 to the transition metal sulfate solution, to co-precipitate and obtain the cathode material precursor Ni. 0.30 Co 0.06 Mn 0.64 (OH)2, and Li, a lithium-rich manganese-based cathode material, was prepared using this precursor. 1.144 Ni 0.258 Co 0.055 Mn 0.543 O2. Compared to the precursor obtained without the complexing agent in Comparative Example 2, and the lithium-rich manganese-based cathode material obtained from this precursor, and compared to the precursor obtained without the complexing agent and surfactant in Comparative Example 1, and the lithium-rich manganese-based cathode material obtained from this precursor, the lithium-rich manganese-based cathode material in Example 3 contains spherical bodies formed by primary particle stacking and needle-like clusters formed by primary particles arranged linearly. The diameter of the spherical bodies is 4.3 μm and the length of the needle-like clusters is 1.7 μm. The diameter of the spherical bodies and the length of the needle-like clusters are... The increased cluster length is beneficial for improving the stability of the cathode material particle structure, increasing the specific surface area of ​​the cathode material particles, facilitating the rapid insertion and extraction of lithium ions, and increasing the diffusion rate of lithium ions. As a result, the prepared lithium-rich manganese-based cathode material has a higher compaction density and energy density compared to the lithium-rich manganese-based cathode materials in Comparative Examples 1 and 2. It also has a higher first-time efficiency in charge-discharge tests, a higher 0.33C discharge specific capacity, and better energy retention after 100 cycles, thus improving the rate performance of lithium-ion battery cells.

[0184] In conjunction with Example 4 and Comparative Examples 1-2,

[0185] Example 4 involved adding a 0.75 mol / L sodium ethylenediaminetetraacetate complexing agent, a 2.5 mol / L transition metal sulfate solution, and a cetyltrimethylammonium bromide (CTAB) surfactant at a mass ratio of 0.6:100 to the transition metal sulfate solution, to co-precipitate and obtain the cathode material precursor Ni. 0.30 Co 0.06 Mn 0.64 (OH)2, and Li, a lithium-rich manganese-based cathode material, was prepared using this precursor. 1.144 Ni 0.258 Co 0.055 Mn 0.543O2. Compared to the precursor obtained without the complexing agent in Comparative Example 2, and the lithium-rich manganese-based cathode material obtained from this precursor, and compared to the precursor obtained without the complexing agent and surfactant in Comparative Example 1, and the lithium-rich manganese-based cathode material obtained from this precursor, the lithium-rich manganese-based cathode material in Example 4 contains spherical bodies formed by primary particle stacking and needle-like clusters formed by primary particles arranged linearly. The diameter of the spherical bodies is 3.9 μm and the length of the needle-like clusters is 1.6 μm. The diameter of the spherical bodies and the length of the needle-like clusters are... The increased cluster length is beneficial for improving the stability of the cathode material particle structure, increasing the specific surface area of ​​the cathode material particles, facilitating the rapid insertion and extraction of lithium ions, and increasing the diffusion rate of lithium ions. As a result, the prepared lithium-rich manganese-based cathode material has a higher compaction density and energy density compared to the lithium-rich manganese-based cathode materials in Comparative Examples 1 and 2. It also has a higher first-time efficiency in charge-discharge tests, a higher 0.33C discharge specific capacity, and better energy retention after 100 cycles, thus improving the rate performance of lithium-ion battery cells.

[0186] In conjunction with Example 5 and Comparative Examples 1-2,

[0187] Example 5 involved adding a 0.4 mol / L sodium ethylenediaminetetraacetate complexing agent, a 2.5 mol / L transition metal sulfate solution, and sodium dodecyl sulfate (SDS) surfactant at a mass ratio of 5:100 to the transition metal sulfate solution, to co-precipitate and obtain the cathode material precursor Ni. 0.30 Co 0.06 Mn 0.64 (OH)2, and Li, a lithium-rich manganese-based cathode material, was prepared using this precursor. 1.144 Ni 0.258 Co 0.055 Mn 0.543 O2. Compared to the precursor obtained without a complexing agent in Comparative Example 2, and the lithium-rich manganese-based cathode material obtained from this precursor, and compared to the precursor obtained without a complexing agent and surfactant in Comparative Example 1, the lithium-rich manganese-based cathode material in Example 5 contains spherical bodies formed by primary particle stacking and needle-like clusters formed by primary particles arranged linearly. The diameter of the spherical bodies is 5 μm and the length of the needle-like clusters is 1.4 μm. At this spherical body diameter and needle-like cluster length, it is beneficial to improve the stability of the cathode material particle structure, improve the specific surface area of ​​the cathode material particles, facilitate the rapid insertion and extraction of lithium ions, and increase the diffusion rate of lithium ions. As a result, the prepared lithium-rich manganese-based cathode material has a higher compaction density and higher energy density than the lithium-rich manganese-based cathode materials in Comparative Examples 1 and 2. It also has a higher first-time efficiency in charge-discharge tests, a higher 0.33C discharge specific capacity, and better energy retention after 100 cycles, thus improving the rate performance of lithium-ion battery cells.

[0188] In conjunction with Example 6 and Comparative Examples 1-2,

[0189] Example 6 involved adding a 0.75 mol / L sodium ethylenediaminetetraacetate complexing agent, a 2.5 mol / L transition metal sulfate solution, and a cetyltrimethylammonium bromide (CTAB) surfactant at a mass ratio of 0.6:100 to the transition metal sulfate solution, to co-precipitate and obtain the cathode material precursor Ni. 0.30 Co 0.06 Mn 0.64 (OH)2, and Li, a lithium-rich manganese-based cathode material, was prepared using this precursor. 1.144 Ni 0.258 Co 0.055 Mn 0.543 O2. Compared to the precursor obtained without the complexing agent in Comparative Example 2, and the lithium-rich manganese-based cathode material obtained from this precursor, and compared to the precursor obtained without the complexing agent and surfactant in Comparative Example 1, and the lithium-rich manganese-based cathode material obtained from this precursor, the lithium-rich manganese-based cathode material in Example 6 contains spherical bodies formed by primary particle stacking and needle-like clusters formed by primary particles arranged linearly. The diameter of the spherical bodies is 3.9 μm and the length of the needle-like clusters is 1.6 μm. The diameter of the spherical bodies and the length of the needle-like clusters are... The increased cluster length is beneficial for improving the stability of the cathode material particle structure, increasing the specific surface area of ​​the cathode material particles, facilitating the rapid insertion and extraction of lithium ions, and increasing the diffusion rate of lithium ions. As a result, the prepared lithium-rich manganese-based cathode material has a higher compaction density and energy density compared to the lithium-rich manganese-based cathode materials in Comparative Examples 1 and 2. It also has a higher first-time efficiency in charge-discharge tests, a higher 0.33C discharge specific capacity, and better energy retention after 100 cycles, thus improving the rate performance of lithium-ion battery cells.

[0190] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A lithium-ion battery cell, characterized in that, include: Positive electrode sheet, wherein the positive electrode sheet comprises a lithium-rich manganese-based positive electrode material; The lithium-rich manganese-based cathode material includes spherical bodies formed by primary particle stacking and needle-like clusters formed by linear arrangement of the primary particles, with the needle-like clusters radially distributed on the surface of the spherical bodies; The diameter of the spherical body is 1µm to 5µm, and the length of the needle-like clusters is 1µm to 7µm.

2. A method of producing a lithium-ion battery cell, characterized by, include: Transition metal salts, complexing agents, and surfactants were co-precipitated to obtain lithium-rich manganese-based cathode material precursors; The complexing agent includes a compound having a carboxyl group and a hydroxyl group, or the complexing agent includes a compound having a carboxyl group and an amino group; The mass ratio A of the surfactant to the transition metal salt satisfies: 1:1000≤A≤1:20; The lithium-rich manganese-based cathode material precursor is used to prepare a lithium-rich manganese-based cathode material with a spherical morphology formed by primary particle stacking and needle-like clusters formed by the linear arrangement of the primary particles radially distributed on the surface of the spherical morphology. We provide positive electrode plates, separators, and negative electrode plates; Providing the positive electrode sheet includes: coating a slurry comprising the lithium-rich manganese-based positive electrode material onto the surface of a positive electrode current collector to prepare the positive electrode sheet; The positive electrode, the separator, and the negative electrode are assembled in sequence to prepare an electrode assembly; The electrode assembly is used to prepare the lithium-ion battery cell.

3. A positive electrode material, characterized in that, The cathode material is a lithium-rich manganese-based cathode material; The lithium-rich manganese-based cathode material includes spherical bodies formed by primary particle stacking and needle-like clusters formed by linear arrangement of the primary particles, with the needle-like clusters radially distributed on the surface of the spherical bodies; The diameter of the spherical body is 1µm to 5µm, and the length of the needle-like clusters is 1µm to 7µm.

4. The positive electrode material according to claim 3, characterized in that, The particle size distribution Dv50 of the lithium-rich manganese-based cathode material satisfies: 4um to 12um.

5. The positive electrode material according to claim 3 or 4, characterized in that, The particle size distribution Dv50 of the lithium-rich manganese-based cathode material satisfies: 4um to 8um.

6. The cathode material according to any one of claims 3 to 5, characterized in that, The compaction density of the lithium-rich manganese-based positive electrode material satisfies: 2.8 g / cm 3 ~ 3.13 g / cm 3 .

7. A method for preparing a positive electrode material, characterized in that, include: Transition metal salts, complexing agents, and surfactants were co-precipitated to obtain lithium-rich manganese-based cathode material precursors; The complexing agent includes a compound having a carboxyl group and a hydroxyl group, or the complexing agent includes a compound having a carboxyl group and an amino group; The mass ratio A of the surfactant to the transition metal salt satisfies: 1:1000≤A≤1:20; The lithium-rich manganese-based cathode material precursor is used to prepare a lithium-rich manganese-based cathode material with a spherical morphology formed by primary particle stacking and needle-like clusters formed by the linear arrangement of the primary particles radially distributed on the surface of the spherical morphology.

8. The preparation method according to claim 7, characterized in that, The mass ratio A of the surfactant to the transition metal salt satisfies: 1:800 ≤ A ≤ 1:

50.

9. The production method according to claim 7 or 8, characterized by, The concentration α of the complexing agent satisfies: 0.1 mol / L ≤ α ≤ 2 mol / L.

10. The production method according to any one of claims 7 to 9, characterized by, The concentration α of the complexing agent satisfies: 0.4 mol / L ≤ α ≤ 1.8 mol / L.

11. The production method according to any one of claims 7 to 10, characterized by, The surfactant includes at least one of sodium dodecyl sulfate (SDS), hexadecyltrimethylammonium bromide (CTAB), polyvinylpyrrolidone (PVP), and sodium dodecylbenzene sulfonate (SDBS).

12. The production method according to any one of claims 7 to 11, characterized by, The complexing agent includes at least one of salicylates, citrates, ethylenediaminetetraacetic acid, tartrates, and gluconates.

13. The production method according to any one of claims 7 to 12, characterized by, The transition metal salts include: sulfate transition metal salts, nitrate transition metal salts, acetic acid transition metal salts, and chloride transition metal salts, wherein the transition metals include one or more combinations of Ni, Co, Mn, Al, Cr, Fe, Nb, Zr, W, and Mg.

14. The preparation method according to any one of claims 7 to 13, characterized in that, During the co-precipitation process, the pH in the reactor satisfies: 8 ≤ pH ≤ 12, the temperature T in the reactor satisfies: 25℃ ≤ T ≤ 50℃, and the rotational speed R in the reactor satisfies: 600 rpm ≤ R ≤ 1200 rpm.

15. The production method according to any one of claims 7 to 14, characterized by, The lithium-rich manganese-based cathode material precursor satisfies one or more of the following conditions: The particle size distribution Dv50 of the lithium-rich manganese-based cathode material precursor satisfies 2μm≤Dv50≤15μm; The particle size distribution span SPAN of the lithium-rich manganese-based cathode material precursor satisfies 0.5≤SPAN≤1.2; The tap density C of the lithium-rich manganese-based cathode material precursor satisfies 1.3 g / cc ≤ C ≤ 2.0 g / cc; The specific surface area D of the lithium-rich manganese-based positive electrode material precursor satisfies 15 m 2 / g≤D≤50 m 2 / g.

16. The preparation method according to any one of claims 7 to 15, characterized in that, The lithium-rich manganese-based cathode material precursor satisfies one or more of the following conditions: The particle size distribution Dv50 of the lithium-rich manganese-based cathode material precursor satisfies 3μm≤Dv50≤10μm; The particle size distribution span SPAN of the lithium-rich manganese-based cathode material precursor satisfies 0.5≤SPAN≤1.1; The tap density C of the lithium-rich manganese-based cathode material precursor satisfies 1.5 g / cc ≤ C ≤ 1.8 g / cc; The specific surface area D of the lithium-rich manganese-based positive electrode material precursor satisfies: 20 m 2 / g≤D≤40 m 2 / g.

17. A battery, characterized by Includes the lithium-ion battery cell as described in claim 1, and / or the lithium-ion battery cell prepared by the method as described in claim 2.

18. An electrical device, comprising: Includes the battery as described in claim 17.

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