Lithium ion battery cathode material, preparation method and application thereof

Abstract

The application discloses a lithium ion battery positive electrode material, a preparation method and application thereof, wherein the positive electrode material comprises LiNi x Co y Mn (1‑x‑y‑z) M z O2, wherein M is composed of at least three kinds of metals, and x is greater than or equal to 0.8, x+y is less than or equal to 0.95, and z is less than or equal to 0.05. The lithium ion battery positive electrode material adopts a high-entropy doping mode, a plurality of metal elements are doped at the same time, the performance of the nickel-cobalt-manganese ternary material is improved in multiple aspects, and therefore the comprehensive performance of the nickel-cobalt-manganese ternary material is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium ion battery cathode materials, in particular to a lithium ion battery cathode material, a preparation method and application thereof. BACKGROUND

[0002] Nickel cobalt manganese ternary material (NCM) is one of common lithium ion battery cathode materials. With the increase of Ni content, the capacity of the material increases, but the electrochemical performance such as cycle and rate decreases. The main reasons are as follows: the local strain concentration caused by non-uniform volume change forms multi-scale cracks, thereby directly leading to mechanical failure of the cathode material, making the structural stability of the material poor, and reducing the cycle stability of the material; the inevitable side reactions at the material interface increase the diffusion impedance of Li + , resulting in a substantial reduction in the capacity of the material and a decrease in the rate performance; in addition, the cracks in the material cause the electrolyte to erode the inside of the material, and the harmful cracking and high-reactivity surface synergistically exacerbate thermal instability, reducing the electrochemical performance of the material.

[0003] To solve the above problems, the existing technologies mainly include concentration gradient structure, surface coating, ion doping and the like. The concentration gradient structure design can effectively dissipate the local strain caused by lattice shrinkage and inhibit the formation of micro-cracks, but the concentration gradient in the hydroxide precursor of this technology is essentially unstable and is prone to be flattened through mutual diffusion during lithiation; the surface coating modification method can reduce the side reactions at the material interface, protect the material from being eroded by the electrolyte, and improve the lithium ion / electron conductivity, but the problem of loose coating layer and material combination cannot be avoided; ion doping can use a doping element to replace part of lithium ions, transition metal ions or oxygen ions in the material, enhance the structural stability, and improve the cycle stability of the material, but the conventional ion doping is completed by calcining the cathode material with a dopant, which causes the ion doping to only occur in the near-surface layer of the cathode material, and cannot uniformly penetrate into the inside of the cathode material, so that the modification effect of ion doping on the material cannot be fully exerted.

[0004] The above existing technologies have targeted modification effects on the lithium ion battery cathode material, but still have respective deficiencies. In view of this, the present application is proposed. SUMMARY

[0005] The present application aims to provide a preparation method of a lithium ion battery cathode material and a lithium ion battery cathode material obtained by the method.

[0006] The present application is implemented as follows:

[0007] In a first aspect, the present application provides a cathode material, comprising LiNi x Co y Mn(1-x-y-z) M z O2, wherein M consists of at least three metals, and x≥0.8, x+y≤0.95, z≤0.05.

[0008] In an alternative embodiment, the M consists of at least three metals selected from Mg, Sb, Nb, V, Ta, Mo, Ti and Zr.

[0009] In an alternative embodiment, the LiNi x Co y Mn (1-x-y-z) M Z O2 is coated with a shell layer, the shell layer comprising LiGO2-G2O3, the G being at least one of B, Al, In, Ga, Sn.

[0010] In a second aspect, the present application provides a method for preparing the positive electrode material of any one of the preceding embodiments, comprising:

[0011] mixing step, mixing Ni x Co y Mn (1-x-y-z) M z (OH)2and a lithium source to obtain a first mixture;

[0012] synthesis step, calcining the first mixture at 720-750℃ to obtain LiNi x Co y Mn (1-x-y-z) M z O2.

[0013] In an alternative embodiment, the synthesis step satisfies at least one of the following ①-④:

[0014] ① the lithium source is LiOH·H2O;

[0015] ② the amount of the lithium source is 100-110% of the theoretical amount;

[0016] ③ the calcination time is 10-15h;

[0017] ④ the calcination is performed in an oxygen atmosphere.

[0018] In an alternative embodiment, the method further comprises preparing Ni x Co y Mn (1-x-y-z) M z (OH)2: comprising placing a nickel ion source, a manganese ion source, a cobalt ion source and an M ion source in an alkaline solution to react to generate Ni x Co y Mn (1-x-y-z) Mz (OH)2;

[0019] Preferably, the Ni x Co y Mn (1-x-y-z) M z The preparation of the Ni

[0020] ① the nickel ion source is an inorganic nickel salt;

[0021] ② the manganese ion source is an inorganic manganese salt;

[0022] ③ the cobalt ion source is an inorganic cobalt salt;

[0023] ④ the M ion source is an aqueous salt of M;

[0024] ⑤ the molar ratio of nickel ions, cobalt ions, manganese ions and M ions in the alkaline solution is x:y:(1-x-y-z):z, wherein x≥0.8, x+y≤0.95, and z≤0.05;

[0025] ⑥ the concentration of M ions in the alkaline solution is 0.9-1.1 mol / L;

[0026] ⑦ the pH of the alkaline solution is 10-12;

[0027] ⑧ the reaction temperature is 40-60℃;

[0028] ⑨ the reaction is carried out in an inert gas environment;

[0029] ⑩ after the reaction, the reaction liquid is subjected to solid-liquid separation, washing, drying, and grinding to obtain the Ni x Co y Mn (1-x-y-z) M z (OH)2particles.

[0030] In an optional embodiment, a coating step is further included: the G-containing component is mixed with LiNi x Co y Mn (1-x-y-z) M z O2to obtain a mixture, and the mixture is dried and calcined to obtain coated LiNi x Co y Mn (1-x-y-z) M z O2.

[0031] In an optional embodiment, the coating step satisfies at least one of the following ①-⑤:

[0032] ① in the mixing step, anhydrous ethanol is further added;

[0033] ii) the G-containing component is a G salt that is soluble in ethanol;

[0034] iii) the G-containing component and LiNi x Co y Mn (1-x-y-z) M z O2 in a mass ratio of 1-2:98-99;

[0035] iv) the drying step is performed at a temperature of 100-120℃ for 15-20h;

[0036] v) the calcination step is performed at a temperature of 500-650℃ for 2-6h.

[0037] In a third aspect, the present application provides a battery comprising the positive electrode material according to any one of the preceding embodiments.

[0038] In a fourth aspect, the present application provides an electrical device comprising the battery according to any one of the preceding embodiments.

[0039] The present application has the following advantages:

[0040] The lithium ion battery positive electrode material of the present application adopts a high-entropy doping method, which improves the performance of nickel-cobalt-manganese ternary materials in multiple aspects by simultaneously doping multiple metal elements, thereby improving the comprehensive performance of nickel-cobalt-manganese ternary materials.

[0041] The lithium ion battery positive electrode material of the present application first adds M salt in the precursor stage to obtain a Ni x Co y Mn (1-x-y-z) M z (OH)2 precursor material. Compared with calcining the positive electrode material and the dopant, the doping elements can relatively uniformly penetrate into the positive electrode material, which helps the doping elements to be uniformly distributed in the material lattice, expands the interlayer spacing, inhibits the collapse of local structure, prevents the generation of micro-cracks, and inhibits the release of oxygen under high pressure. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be considered as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0043] Figure 1 XRD comparison chart of Example 1 and Comparative Example 1;

[0044] Figure 2Cycle performance comparison chart of Example 1 and Comparative Example 1;

[0045] Figure 3 Rate performance comparison chart of Example 1 and Comparative Example 1;

[0046] Figure 4 EIS comparison chart of Example 1 and Comparative Example 1. DETAILED DESCRIPTION

[0047] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below. If specific conditions are not specified in the embodiments, conventional conditions or conditions suggested by manufacturers are adopted. If the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased in the market.

[0048] The present embodiment provides a lithium ion battery cathode material, which comprises LiNi x Co y Mn (1-x-y-z) M z O2, wherein M is composed of at least three metals, and x≥0.8, x+y≤0.95, and z≤0.05.

[0049] The lithium ion battery cathode material of the present application adopts a high-entropy doping method, and the performance of the nickel-cobalt-manganese ternary material is improved in multiple aspects by simultaneously doping multiple metal elements, thereby being beneficial to improving the comprehensive performance of the nickel-cobalt-manganese ternary material.

[0050] In the present embodiment, the doping amounts of nickel, cobalt, manganese and M in the ternary cathode material are also studied, and within the composition of the present application, the material stability and electrochemical performance are greatly improved.

[0051] In some optional embodiments, the M is composed of at least three metals selected from Mg, Sb, Nb, V, Ta, Mo, Ti and Zr. Compared with other elements, these elements have high oxidation states, and can stabilize the layered cathode at the microscopic and atomic levels as dopants. For example, M can be three elements of Mg, Sb and Nb, four elements of Sb, Nb, V and Ta, five elements of Nb, V, Ta, Mo and Ti, or even more elements. The selection of specific doping elements can be comprehensively considered from aspects of reducing anisotropic lattice collapse of the electrode (such as Mg, Nb, Ti, etc.), reducing oxygen escape (such as Zr, Sb, V, etc.), and inhibiting cation mixing (such as Ta, Mo, Sb, etc.), so as to achieve the modification effects of stabilizing the layered structure of the cathode material, enhancing the rate performance of the material, inhibiting the increase of internal resistance during the cycle process, and improving the capacity retention rate of the material.

[0052] In some optional embodiments, the LiNi x Co yMn (1-x-y-z) M Z O2 is coated with a shell layer, and the shell layer comprises LiGO2-G2O3, and the G is at least one of B, Al, In, Ga, and Sn.

[0053] The interface side reaction of the lithium ion battery cathode material is an important factor affecting the electrochemical performance of the material. After the LiGO2-G2O3 coating is performed on the material interface, the material can be effectively protected from being eroded by the electrolyte, the side reaction product is reduced, the interface impedance of the material is reduced, and thus the cycle stability of the material is enhanced.

[0054] The formation of LiGO2 in the coating layer, i.e. the shell layer, will consume the residual lithium in the interface of the cathode material, reduce the interface side reaction, and LiGO2 is a good lithium ion conductor with a similar layered structure to the cathode material, which is not only beneficial to the coating layer of the material interface, but also can accelerate the diffusion of lithium ions and enhance the rate performance of the material.

[0055] In the embodiment, the G can be selected from B, Al, In, Ga, and Sn. Compared with other elements, the G2O3 generated by these elements can react with the residual lithium on the surface of the cathode material to generate LiGO2 with good lithium ion conductivity, which can not only eliminate the side reaction caused by residual alkali, but also improve the lithium ion conductivity of the material, thereby improving the electrochemical performance of the material. Specifically, the G can be selected from only one of B, Al, In, Ga, and Sn, or a combination of two or more, for example, the G can include B and Al, or Al, In, and Ga. The selection of the specific G element can be considered in combination with the preparation conditions (such as calcination temperature, time) of G2O3 and LiGO2 formed by different G elements, particle size, and material properties (such as Al2O3 can react with LiPF6 to generate electrolyte additive LiPO2F2).

[0056] In a second aspect, the application provides a method for preparing the cathode material of any one of the preceding embodiments, comprising:

[0057] In the mixing step, Ni x Co y Mn (1-x-y-z) M z (OH)2 and a lithium source are mixed to obtain a first mixture;

[0058] In the synthesis step, the first mixture is calcined at 720-750℃ to obtain LiNi x Co y Mn (1-x-y-z) M z O2.

[0059] The lithium ion battery cathode material of the application first adds M salt in the precursor stage to obtain a Nix Co y Mn (1-x-y-z) M z Compared with the calcination of the positive electrode material with the dopant, the dopant elements can be relatively uniformly penetrated into the interior of the positive electrode material, which helps the dopant elements to be uniformly distributed in the material lattice, expands the interlayer spacing, enhances the bond energy between the dopant elements and oxygen, inhibits the collapse of local structure, prevents the generation of micro-cracks, and inhibits the release of oxygen under high pressure.

[0060] For the synthesis step step:

[0061] In some alternative embodiments, the lithium source is LiOH H2O.

[0062] In some alternative embodiments, the amount of the lithium source is 100-110% of the theoretical amount, for example, it can be 100%, 102%, 104%, 106%, 108%, and 110%, preferably 105%, wherein the theoretical amount is calculated according to the structural formula to synthesize LiNi x Co y Mn (1-x-y-z) M z The mass of the lithium source required by the LiNi

[0063] In some alternative embodiments, the mixture of Ni x Co y Mn (1-x-y-z) M z (OH)2and the lithium source is calcined at 720-750°C for 10-15h, specifically, the calcination temperature can be 720°C, 730°C, 740°C, or 750°C, and the calcination time can be 10h, 11h, 12h, 13h, 14h, or 15h. The calcination temperature in this embodiment is selected to be 720-750°C, mainly because at this temperature range, the high-nickel positive electrode material with high crystallinity, good layered structure, and low cation mixing can be formed. If the temperature is too high, the loss of Li increases, the morphology and structure of the material are destroyed, resulting in a decrease in the structural stability of the material and a decrease in the electrochemical performance; if the temperature is too low, the material crystallization is incomplete, and it is difficult to form more complete Li + The diffusion channels are limited, and the capacity of the material is limited; and the calcination time is too long, which can destroy the structure of the product, and maintaining a high temperature is not conducive to cost saving.

[0064] In some alternative embodiments, the method further comprises preparing Ni x Co y Mn (1-x-y-z) M z Preparation of Ni xCo y Mn (1-x-y-z) M z (OH)2, for the step:

[0065] In some alternative embodiments, the nickel ion source is an inorganic nickel salt.

[0066] In some alternative embodiments, the manganese ion source is an inorganic manganese salt.

[0067] In some alternative embodiments, the cobalt ion source is an inorganic cobalt salt.

[0068] In some alternative embodiments, the M ion source is an aqueous salt of M, which can be a chloride salt, a nitrate salt, a sulfate salt, etc.

[0069] In some alternative embodiments, the molar ratio of nickel ions, cobalt ions, manganese ions and M ions in the alkaline solution is x:y:(1-x-y-z):z, wherein x≥0.8, x+y≤0.95, and z≤0.05.

[0070] In some alternative embodiments, the concentration of M ions in the alkaline solution is 0.9-1.1 mol / L.

[0071] In some alternative embodiments, the pH of the alkaline solution is 10-12, so that the product can be precipitated smoothly.

[0072] In some alternative embodiments, the reaction temperature is 40-60°C, and specifically, the reaction temperature can be 40°C, 45°C, 50°C, 55°C or 60°C, and the reaction can be stopped when the precipitation basically no longer occurs at this temperature.

[0073] In some alternative embodiments, the reaction is carried out in an inert gas environment to avoid oxidation of the reactants or products.

[0074] In some alternative embodiments, after the reaction is completed, the reaction liquid is subjected to solid-liquid separation, washing, drying and grinding to obtain Ni x Co y Mn (1-x-y-z) M z (OH)2particles.

[0075] The nickel ion source, the manganese ion source, the cobalt ion source and the M ion source are reacted in an alkaline solution to obtain Ni x Co y Mn (1-x-y-z) M z (OH)2, wherein the doping element M is uniformly distributed in the material lattice, and by limiting the pH of the alkaline solution, the concentration of the reactants and the reaction temperature, the reaction rate and the precipitation rate are favorably controlled.

[0076] In some optional embodiments, a coating step is further included, wherein the G-containing component is mixed with LiNi x Co y Mn (1-x-y-z) M z O2 to obtain a mixture, and the mixture is dried and calcined to obtain a coated LiNi x Co y Mn (1-x-y-z) M z O2, i.e. LiNi x Co y Mn (1-x-y-z) M z O2@LiGO2-G2O3, and for this step:

[0077] In some optional embodiments, anhydrous ethanol is further added in the mixing step, which is beneficial for the sufficient mixing of raw materials.

[0078] In some optional embodiments, the G-containing component is a G salt that can be dissolved in ethanol, which facilitates the mixing step of dissolving in ethanol.

[0079] In some optional embodiments, the mass ratio of the G-containing component to LiNi x Co y Mn (1-x-y-z) M z O2 is 1-2:98-99, and specifically, the mass ratio of the G-containing component to LiNi x Co y Mn (1-x-y-z) M z O2@LiGO2-G2O3 can be 1wt% or 2wt%, and an excessive amount of the G-containing component will result in an excessively thick shell layer, which is not conducive to the passing of lithium ions, and an insufficient amount of the G-containing component will not be able to protect the core.

[0080] In some optional embodiments, the drying step is performed at a temperature of 100-120℃ for 15-20h, and the purpose is to remove ethanol.

[0081] In some optional embodiments, the calcination step is performed at a temperature of 500-650℃ for 2-6h, and specifically, the temperature can be 530℃, 560℃, 590℃, 620℃ or 650℃, and the time can be 2h, 3h, 4h, 5h or 6h, wherein the temperature is mainly selected in consideration of the fact that a lower temperature cannot completely form G2O3 and LiGO2, and a higher temperature will cause some G ions to be doped into the interior of the positive electrode material, thereby avoiding the destruction of the crystal structure of the material caused by high-temperature calcination.

[0082] Another embodiment of the present application provides a battery comprising the positive electrode material according to any one of the preceding embodiments.

[0083] Another embodiment of the present application provides a power consuming device comprising the battery of any of the preceding embodiments.

[0084] The features and properties of the present application are further described in detail below in conjunction with the embodiments.

[0085] Embodiment 1

[0086] The present embodiment provides a preparation method of a lithium ion battery cathode material, comprising the following steps:

[0087] (1) Preparation of precursor: In advance, inert gas is introduced into the container, NiSO4·6H2O, MnSO4, CoSO4·7H2O, M salt are weighed according to the molar ratio (Ni=0.8, Co=0.075, Mn=0.075; M is Nb, V, Ta and Mo elements, the total amount is 0.05), 1000 mL of deionized water is measured, and is placed in the container for magnetic stirring for 10 h to prepare a 1 moL / L transition metal solution; sodium hydroxide and ammonium hydroxide are used to prepare an alkali solution, and 30 mL is taken as a starting solution, diluted with sulfuric acid to adjust the pH of the starting solution to 11, then the transition metal solution and the alkali solution are injected at the same time under inert gas environment, the product is synthesized under the conditions of pH=11 and 50℃, and then washed, dried and ground to obtain LiNi 0.8 Co 0.075 Mn 0.075 M 0.05 (OH)2 precursor.

[0088] (2) Preparation of cathode material: after the dried precursor powder is mixed with excess 5% LiOH·H2O, oxygen is passed at 740℃ for calcination for 15 h, and then ground to obtain LiNi 0.8 Co 0.075 Mn 0.075 M 0.05 O2 cathode material.

[0089] (3) Surface coating: 1 wt.% of In nitrate is calculated and dissolved in an appropriate amount of anhydrous ethanol, and then LiNi 0.8 Co 0.075 Mn 0.075 M 0.05 O2 is fully mixed, dried at 100℃ for 15 h, and then calcined at 600℃ for 4 h to obtain LiNi 0.8 Co 0.075 Mn 0.075 M 0.05 O2@LiInO2-In2O3 cathode material.

[0090] (4) The prepared LiNi 0.8Co 0.075 Mn 0.075 M 0.05 O2@LiInO2-In2O3 assembled into batteries for electrochemical performance testing.

[0091] Example 2:

[0092] This example provides a preparation method of a lithium ion battery cathode material, which is only different from example 1 in that no M salt is added in step (1).

[0093] Example 3:

[0094] This example provides a preparation method of a lithium ion battery cathode material, which is only different from example 1 in that step (3) is not performed.

[0095] Comparative Example 1

[0096] This comparative example provides a preparation method of a lithium ion battery cathode material, which includes the following steps:

[0097] (1) Preparation of precursor: In advance, inert gas is introduced into the container, NiSO4·6H2O, MnSO4, CoSO4·7H2O are weighed according to a molar ratio of 8:1:1, 1000 mL of deionized water is measured and placed in the container for magnetic stirring for 10 h to prepare a 1 mol / L transition metal solution; sodium hydroxide and ammonium hydroxide are used to prepare an alkali solution, and 30 mL is taken as the starting solution, diluted with sulfuric acid to adjust the pH of the starting solution to 11, then the transition metal solution and the alkali solution are injected simultaneously in an inert gas environment, and the product is synthesized under the conditions of pH = 11 and 50°C. After stirring, washing, drying and grinding, the Ni x Co y Mn (1-x-y) (OH)2 precursor is obtained.

[0098] (2) Preparation of cathode material: After mixing the dried precursor powder with an excess of 5% LiOH·H2O, oxygen calcination is performed at 740°C for 15 h, and after grinding, the Ni x Co y Mn (1-x-y) O2 cathode material is obtained.

[0099] (3) The prepared Ni x Co y Mn (1-x-y) O2 is assembled into batteries for electrochemical performance comparison testing.

[0100] The XRD patterns of the cathode materials obtained in example 1 and comparative example 1 are shown in Figure 1 , Figure 1The XRD pattern of example 1 and the XRD pattern of comparative example 1 are consistent with the NCM pattern, and are R-3m space group hexagonal LiNiO2 structure. Figure 1 In b, the diffraction peaks of example 1 (003) and (104) shift to low angles, which proves that the M element is indeed doped into the lattice of the positive electrode material; because the coating amount is small, no diffraction peak related to the coating appears in the XRD pattern of example 1. The I (003) / I (104) are 1.43 and 1.22 respectively, which indicates that example 1 has a lower degree of cationic disordering.

[0101] The comparison chart of the cycle performance of the positive electrode materials obtained from example 1 and comparative example 1 is shown in Figure 2 After 600 cycles at 25℃, 1C, 2.8-4.35V, the capacity retention rates of example 1 and comparative example 1 are 92.50% and 73.43% respectively. The capacity retention rate of example 1 is increased by 19.07% compared with that of comparative example 1, which indicates that this method can effectively improve the cycle stability of the positive electrode material.

[0102] The comparison chart of the rate performance and EIS of the positive electrode materials obtained from example 1 and comparative example 1 is shown in Figure 3 and Figure 4 It can be seen from Figure 3 and Figure 4 that the rate performance of example 1 is obviously better than that of comparative example 1, due to the M doping element and LiGO2 in the coating material; the charge transfer impedance Rct of example 1 and comparative example 1 are 10.65Ω and 13.45Ω respectively, which indicates that example 1 can effectively reduce the interface side reaction of the positive electrode material, so as to enhance the electrochemical performance of the material, which corresponds to the cycle and rate test results.

[0103] The electrochemical performance of the positive electrode materials obtained from example 1-3 and comparative example is tested, and table 1 is obtained, from which it can be seen that simultaneous coating and doping can significantly improve the electrochemical performance of the material.

[0104] Table 1 electrochemical performance data

[0105]

[0106] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A positive electrode material, characterized in that, Including LiNi x Co y Mn (1-x-y-z) M z O2, the LiNi x Co y Mn (1-x-y-z) M z The precursor of O2 is Ni x Co y Mn (1-x-y-z) M z (OH)2, wherein M is composed of at least three metals, and x≥0.8, x+y≤0.95, z≤0.05; The LiNi x Co y Mn (1-x-y-z) M Z The O2 is covered by a shell, which includes LiGO2-G2O3, wherein G is at least one of B, Al, In, Ga, and Sn; The M is composed of at least three metals selected from Mg, Sb, Nb, V, Ta, Mo, Ti and Zr.

2. A method for preparing the cathode material as described in claim 1, characterized in that, include: The mixing step involves mixing Ni x Co y Mn (1-x-y-z) M z (OH)2 and a lithium source are mixed to obtain a first mixture; In the synthesis step, the first mixture is calcined at 720–750°C to obtain LiNi. x Co y Mn (1-x-y-z) M z O2; also includes Ni x Co y Mn (1-x-y-z) M z Preparation of (OH)₂: This involves reacting nickel ion source, manganese ion source, cobalt ion source, and M ion source in an alkaline solution to generate Ni. x Co y Mn (1-x-y-z) M z (OH)2, the Ni x Co y Mn (1-x-y-z) M z The preparation of (OH)2 satisfies at least one of the following ①-⑩: ①The nickel ion source is an inorganic nickel salt; ②The manganese ion source is an inorganic manganese salt; ③The cobalt ion source is an inorganic cobalt salt; ④ The M ion source is an aqueous salt of M; ⑤ The molar ratio of nickel ions, cobalt ions, manganese ions and M ions in the alkaline solution is x:y:(1-xyz):z, where x≥0.8, x+y≤0.95, and z≤0.05; ⑥ The concentration of M ions in the alkaline solution is 0.9-1.1 mol / L; ⑦ The pH of the alkaline solution is 10-12; ⑧ The reaction temperature is 40–60℃; ⑨ The reaction is carried out in an inert gas environment; ⑩ After the reaction is complete, the reaction solution is subjected to solid-liquid separation, washing, drying, and grinding to obtain Ni. x Co y Mn (1-x-y-z) M z (OH)2 particles.

3. The method according to claim 2, characterized in that, The synthesis step satisfies at least one of the following ①-④: ①The lithium source is LiOH·H2O; ② The amount of lithium source used is 100-110% of the theoretical amount; ③ The calcination time is 10–15 hours; ④ The calcination is carried out in an oxygen-rich atmosphere.

4. The method according to claim 3, characterized in that, It also includes a coating step: reacting the G-containing component with LiNi x Co y Mn (1-x-y-z) M z O2 was mixed to obtain a mixture, which was then dried and calcined to obtain coated LiNi. x Co y Mn (1-x-y-z) M z O2.

5. The method for preparing the cathode material according to claim 4, characterized in that, The coating step satisfies at least one of the following ①-⑤: ① Anhydrous ethanol is also added in the mixing step; ②The G-containing component is a G salt that is soluble in ethanol; ③ The G-containing component and LiNi x Co y Mn (1-x-y-z) M Z The mass ratio of O2 is 1-2:98-99; ④ The drying step is performed at a temperature of 100-120℃ for 15-20 hours. ⑤ The calcination step is performed at a temperature of 500-650℃ for 2-6 hours.

6. A battery comprising the positive electrode material of claim 1.

7. An electrical device, characterized in that, Includes the battery as described in claim 6.

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