Nickel-cobalt-manganese precursor and preparation method therefor, and nickel-cobalt-manganese ternary positive electrode material and preparation method therefor

Abstract

The present application relates to a nickel-cobalt-manganese precursor and a preparation method therefor, and a nickel-cobalt-manganese ternary positive electrode material and a preparation method therefor. The nickel-cobalt-manganese precursor has a molecular formula of NixCoyMn(1-x-y)(OH)2, wherein 0<x<1, 0<y<1, and x+y<1, and the nickel-cobalt-manganese precursor has an FWHM(001) of 0.459-0.493, and an FWHM(101) of 0.49-0.552. A nickel-cobalt-manganese ternary positive electrode material is prepared by using the nickel-cobalt-manganese precursor, and a D003 crystal plane of the nickel-cobalt-manganese ternary positive electrode material has a grain size of 80-115 nm, and a D104 crystal plane has a grain size of 40-55 nm. The nickel-cobalt-manganese ternary positive electrode material has both an excellent capacity and high-temperature cycling performance and is prepared at a relatively low temperature, so that the energy consumption cost is effectively reduced.

Description

Nickel-cobalt-manganese precursor and preparation method thereof, nickel-cobalt-manganese ternary positive electrode material and preparation method thereof

[0001] This application claims the benefit of Chinese patent application No. 2024103301396, filed on March 21, 2024. This application incorporates the entirety of the aforementioned Chinese patent application. Technical Field

[0002] The present application relates to the field of lithium battery technology, and in particular to a nickel-cobalt-manganese precursor and a preparation method thereof, a nickel-cobalt-manganese ternary positive electrode material and a preparation method thereof. Background Art

[0003] After years of development, the lithium-ion battery industry has become a mainstay of the new energy sector. The preparation of high-performance cathode materials is undoubtedly a research priority across the entire supply chain. Studies have shown that if the grain size of the nickel-cobalt-manganese ternary cathode material is too small, the material's crystallinity is insufficient. If the grain size is too large, the material tends to be more single-crystalline. Both insufficient crystallinity and a tendency toward single crystallinity can lead to decreased capacity and high-temperature cycling performance.

[0004] To this end, traditional technical solutions usually control the grain size by adjusting the lithium content or doping elements to achieve both better capacity and high-temperature cycle performance. However, all of the above methods require a trade-off between capacity and high-temperature cycle performance. When the grain size decreases, the crystallinity of the nickel-cobalt-manganese ternary positive electrode material deteriorates, the capacity decreases, but the high-temperature cycle performance is good; when the grain size increases, the nickel-cobalt-manganese ternary positive electrode material has good crystallinity and high capacity, but the first discharge capacity is low, and the high-temperature cycle performance also needs to be improved.

[0005] Therefore, there is an urgent need to develop a low-energy preparation method that can enable nickel-cobalt-manganese ternary positive electrode materials to have both excellent capacity and high-temperature cycle performance. Summary of the Invention

[0006] Based on this, it is necessary to provide a nickel-cobalt-manganese precursor and a preparation method thereof, a nickel-cobalt-manganese ternary positive electrode material and a preparation method thereof to address the above problems. When the nickel-cobalt-manganese precursor is used to prepare the nickel-cobalt-manganese ternary positive electrode material, the nickel-cobalt-manganese ternary positive electrode material has both excellent capacity and high-temperature cycle performance, and can be prepared at a lower temperature, effectively reducing energy consumption costs.

[0007] The present application discloses a nickel-cobalt-manganese precursor, the molecular formula of which is Ni x Co y Mn (1-x-y) (OH)2, wherein 0<x<1, 0<y<1, x+y<1, the FWHM of the nickel-cobalt-manganese precursor (001) 0.459-0.493, FWHM (101)It is 0.49-0.552.

[0008] In one embodiment, the nickel-cobalt-manganese precursor satisfies at least one of the following conditions:

[0009] (1) The structure of the nickel-cobalt-manganese precursor is a secondary particle ball formed by the agglomeration of primary particles;

[0010] (2) The tap density of the nickel-cobalt-manganese precursor is 1.95 g / cm 3 -2.00g / cm 3 ;

[0011] (3) The specific surface area of ​​the nickel-cobalt-manganese precursor is 6.22 m 2 / g-8.36m 2 / g;

[0012] (4) D of the nickel-cobalt-manganese precursor 50 The particle size is 8μm-13μm.

[0013] A method for preparing the nickel-cobalt-manganese precursor as described above comprises the following steps:

[0014] The nickel salt, cobalt salt and manganese salt are prepared into a metal salt solution in proportion; and the metal salt solution, alkali solution and ammonia solution are mixed to carry out a coprecipitation reaction. When the D 50 After the particle size reaches the target size, the reaction is completed to obtain the nickel-cobalt-manganese precursor; wherein, in the step of coprecipitation reaction, the nitrogen ventilation rate is 195L / min-240L / min, the ammonia concentration is 6g / L-9g / L, the pH value of the reaction liquid is 10.35-10.95, and the temperature is 55°C-60°C.

[0015] In one embodiment, during the step of performing the coprecipitation reaction, air is introduced at a flow rate of 30 L / min to 45 L / min.

[0016] In one embodiment, the coprecipitation reaction is carried out under stirring conditions, and the stirring speed is 200 rpm-500 rpm.

[0017] In one embodiment, the molar ratio of nickel ions, cobalt ions and manganese ions in the metal salt solution is (85-90):(3-6):(4-12); and / or the alkali solution is an aqueous sodium hydroxide solution.

[0018] In one embodiment, the total concentration of nickel ions, cobalt ions and manganese ions in the metal salt solution is 100 g / L-150 g / L.

[0019] A nickel-cobalt-manganese ternary positive electrode material, wherein the nickel-cobalt-manganese ternary positive electrode material is prepared by solid-phase sintering the nickel-cobalt-manganese precursor as described above, and the D 003 The crystal grain size is 80nm-115nm, D 104 The crystal grain size is 40nm-55nm.

[0020] A method for preparing the nickel-cobalt-manganese ternary positive electrode material as described above comprises the following steps:

[0021] Providing the nickel-cobalt-manganese precursor as described above; and

[0022] The nickel-cobalt-manganese precursor is mixed with lithium hydroxide in proportion and solid-phase sintered to obtain a nickel-cobalt-manganese ternary positive electrode material, wherein in the step of solid-phase sintering, the sintering temperature is less than or equal to 770°C.

[0023] In one embodiment, in the step of performing solid phase sintering, the sintering time is 8 hours to 14 hours.

[0024] When the nickel-cobalt-manganese precursor provided in this application is used to prepare the nickel-cobalt-manganese ternary positive electrode material, the FWHM of the nickel-cobalt-manganese precursor is (001) 0.459-0.493, FWHM (101) The D of the nickel-cobalt-manganese ternary cathode material is 0.49-0.552, and in the solid phase sintering step, the quality of lithium element entering the nickel-cobalt-manganese precursor can be accurately controlled, thereby 003 The crystal grain size is 80nm-115nm, D 104 The crystal grain size is 40nm-55nm, which makes the nickel-cobalt-manganese ternary cathode material have appropriate crystallinity, thereby making the nickel-cobalt-manganese ternary cathode material have both excellent capacity and high temperature cycle performance. In addition, due to the half maximum width FWHM of the nickel-cobalt-manganese precursor 101 The high temperature is conducive to the diffusion of lithium ions, so the crystallinity of the nickel-cobalt-manganese ternary positive electrode material can be improved at a lower temperature, that is, the grain size of the nickel-cobalt-manganese ternary positive electrode material is increased. Therefore, when the nickel-cobalt-manganese precursor provided by the present application is used to prepare the nickel-cobalt-manganese ternary positive electrode material, the solid-phase sintering temperature is reduced to below 770°C, which effectively reduces the energy consumption cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] FIG1 is a half-peak width test graph of the nickel-cobalt-manganese precursor prepared in Example 1;

[0027] FIG2 is a half-peak width test graph of the nickel-cobalt-manganese precursor prepared in Example 2;

[0028] FIG3 is a half-peak width test graph of the nickel-cobalt-manganese precursor prepared in Example 3;

[0029] FIG4 is a half-peak width test graph of the nickel-cobalt-manganese precursor prepared in Example 4;

[0030] FIG5 is a half-peak width test graph of the nickel-cobalt-manganese precursor prepared in Example 5;

[0031] FIG6 is a half-peak width test graph of the nickel-cobalt-manganese precursor prepared in Comparative Example 1;

[0032] FIG7 is a half-peak width test graph of the nickel-cobalt-manganese precursor prepared in Comparative Example 2;

[0033] FIG8 is a half-peak width test graph of the nickel-cobalt-manganese precursor prepared in Comparative Example 3. DETAILED DESCRIPTION

[0034] To facilitate understanding of the present application, the present application will be described in more detail below. However, it should be understood that the present application can be implemented in many different forms and is not limited to the embodiments or examples described herein. On the contrary, the purpose of providing these embodiments or examples is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the art of this application. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments or examples and are not intended to limit this application.

[0036] In the first aspect of the present application, a nickel-cobalt-manganese precursor is provided. The molecular formula of the nickel-cobalt-manganese precursor is Ni x Co y Mn (1-x-y) (OH)2, where 0<x<1, 0<y<1, x+y<1, FWHM of NiCoMn precursor (001) 0.459-0.493, FWHM (101) It is 0.49-0.552.

[0037] Understandable, FWHM (001) Refers to the half-maximum width corresponding to the (001) crystal plane diffraction peak of the nickel-cobalt-manganese precursor, FWHM (101)It refers to the half-peak width corresponding to the diffraction peak of the nickel-cobalt-manganese precursor (101) crystal plane. When the half-peak width is known, the grain size of the corresponding crystal plane can be calculated using the Scherrer formula.

[0038] This application found that when the FWHM of the nickel-cobalt-manganese precursor (001) 0.459-0.493, FWHM (101) When the α-D ratio is 0.49-0.552, the grain size of (001) crystal plane and (101) crystal plane is moderate. In the subsequent solid phase sintering step, the difficulty of lithium element embedding into the nickel-cobalt-manganese precursor is moderate, and the quality of lithium element entering the nickel-cobalt-manganese precursor can be accurately controlled, thereby making the D of the nickel-cobalt-manganese ternary positive electrode material 003 The crystal grain size is 90nm-115nm, D 104 The crystal grain size is 45nm-55nm, which makes the nickel-cobalt-manganese ternary positive electrode material have suitable crystallinity, and thus makes the nickel-cobalt-manganese ternary positive electrode material have both excellent capacity and high-temperature cycle performance.

[0039] FMWH of NiCoMn precursor (001) including but not limited to 0.459, 0.461, 0.463, 0.465, 0.467, 0.469, 0.471, 0.473, 0.475 or 0.477; FWHM (101) 0.49-0.552 includes but is not limited to 0.49, 0.50, 0.51, 0.52 or 0.53.

[0040] The specific surface area of ​​the nickel-cobalt-manganese precursor affects the grain size of the nickel-cobalt-manganese ternary cathode material. In one embodiment, the specific surface area of ​​the nickel-cobalt-manganese precursor is 6.22 m 2 / g-8.36m 2 / g, including but not limited to 6.22m 2 / g, 6.72m 2 / g, 7.22m 2 / g, 7.72m 2 / g、8.22m 2 / g or 8.36m 2 By controlling the specific surface area of ​​the nickel-cobalt-manganese precursor within the above range, the grain size of the nickel-cobalt-manganese ternary positive electrode material prepared from the nickel-cobalt-manganese precursor can be controlled within D 003 The crystal grain size is 90nm-115nm, D 104 The crystal grain size is 45nm-55nm, which is beneficial to improving the capacity and high-temperature cycle performance of nickel-cobalt-manganese ternary positive electrode materials.

[0041] It is understandable that since the nickel-cobalt-manganese ternary positive electrode material has good inheritance in terms of the tap density, particle size and morphology of the nickel-cobalt-manganese precursor, increasing the tap density of the nickel-cobalt-manganese precursor helps to increase the volume energy density of the battery; in one embodiment, the tap density of the nickel-cobalt-manganese precursor is 1.95 g / cm 3 -2.00g / cm 3 ; Including but not limited to 1.95g / cm 3 , 1.96g / cm 3 , 1.97g / cm 3 , 1.98g / cm 3 , 1.99g / cm 3 or 2.00g / cm 3 .

[0042] In one embodiment, the D of the nickel-cobalt-manganese precursor 50 The particle size is 8μm-13μm; including but not limited to 8μm, 9μm, 10μm, 11μm, 12μm or 13μm. By controlling the D50 particle size of the nickel-cobalt-manganese precursor within the above range, on the one hand, it helps to improve the activity of the nickel-cobalt-manganese precursor, making it easier to react with lithium salts to form a nickel-cobalt-manganese ternary cathode material. On the other hand, it has good processability and is not easy to agglomerate. The resulting nickel-cobalt-manganese ternary cathode material has better uniformity, thereby helping to improve the overall performance of the nickel-cobalt-manganese ternary cathode material.

[0043] In one embodiment, the structure of the nickel-cobalt-manganese precursor is a secondary particle sphere formed by agglomeration of primary particles. The nickel-cobalt-manganese precursor having such a structure has high compactness, which is beneficial for improving the tap density of the nickel-cobalt-manganese ternary cathode material prepared from the nickel-cobalt-manganese precursor.

[0044] In a second aspect of the present application, a method for preparing the nickel-cobalt-manganese precursor as described above is provided, comprising the following steps:

[0045] S101, preparing nickel salt, cobalt salt and manganese salt in proportion to form a metal salt solution; and

[0046] S102, mixing the metal salt solution, alkali solution and ammonia solution to perform a coprecipitation reaction. 50 After the particle size reaches the target size, the reaction is completed and a nickel-cobalt-manganese precursor is obtained.

[0047] The preparation method of the nickel-cobalt-manganese precursor provided in the present application is to precisely control the nitrogen ventilation rate, ammonia value, pH value and temperature of the reaction solution during the coprecipitation reaction so that the specific surface area of ​​the nickel-cobalt-manganese precursor is 6.22m 2 / g-8.36m 2 / g, FWHM 101is 0.49-0.552; specifically, in the step of carrying out the coprecipitation reaction, the nitrogen ventilation rate is 195L / min-240L / min, including but not limited to 195L / min, 200L / min, 205L / min, 210L / min, 215L / min, 220L / min, 225L / min, 230L / min, 235L / min or 240L / min, the ammonia concentration is 6g / L-9g / L, including but not limited to 6g / L, 7g / L, 8g / L or 9g / L, the pH of the reaction solution is 10.35-10.95, including but not limited to 10.35, 10.45, 10.55, 10.65, 10.75, 10.85 or 10.95, and the temperature is 55°C-60°C, including but not limited to 55°C, 56°C, 57°C, 58°C, 59°C or 60°C.

[0048] In step S101, optionally, in the step of preparing the metal salt solution, the nickel salt includes at least one of nickel sulfate, nickel chloride, nickel nitrate or nickel acetate, preferably nickel sulfate; the cobalt salt includes at least one of cobalt sulfate, cobalt chloride, cobalt nitrate or cobalt acetate, preferably cobalt sulfate; and the manganese salt includes at least one of manganese sulfate, manganese chloride, manganese nitrate or manganese acetate, preferably manganese sulfate.

[0049] By controlling the molar ratio of nickel ions, cobalt ions and manganese ions, nickel-cobalt-manganese precursors with different ratios can be prepared. In one embodiment, the molar ratio of nickel ions, cobalt ions and manganese ions in the metal salt solution is (85-90):(3-6):(4-12).

[0050] By controlling the molar ratio of nickel ions, cobalt ions and manganese ions within the above range, it is helpful to prepare a nickel-cobalt-manganese ternary positive electrode material with high capacity and excellent high-temperature cyclability.

[0051] Alkali liquor is an aqueous solution of a common alkali, specifically, an aqueous sodium hydroxide solution, which is easily available and suitable for adjusting the pH value of the solution.

[0052] The growth rate of the nickel-cobalt-manganese precursor can be controlled by controlling the total concentration of metal ions in the metal salt solution. In one embodiment, the total concentration of nickel ions, cobalt ions and manganese ions in the metal salt solution is 100 g / L-150 g / L, including but not limited to 100 g / L, 110 g / L, 120 g / L, 130 g / L, 140 g / L or 150 g / L.

[0053] In step S102, during the coprecipitation reaction, air may be introduced at the same time, and the air ventilation rate is 30 L / min-45 L / min, including but not limited to 30 L / min, 35 L / min, 40 L / min or 45 L / min.

[0054] In one embodiment, the coprecipitation reaction is carried out under stirring conditions. During the coprecipitation reaction, stirring can increase the shear force of the fluid, prevent the particles from sticking together and growing in clusters, and accelerate the diffusion of solute ions to prevent the occurrence of local high supersaturation, thereby obtaining seed particles with more uniform particle size and better dispersion; preferably, the stirring speed is 200rpm-500rpm, including but not limited to 200rpm, 300rpm, 400rpm or 500rpm.

[0055] In the third aspect of the present application, a nickel-cobalt-manganese ternary positive electrode material is provided, which is prepared by solid-phase sintering of the nickel-cobalt-manganese precursor as described above, and the D of the nickel-cobalt-manganese ternary positive electrode material is 003 The crystal grain size is 80nm-115nm, D 104 The crystal grain size is 40nm-55nm.

[0056] The experiment found that by controlling the D of the nickel-cobalt-manganese ternary cathode material 003 The crystal grain size is 80nm-115nm, D 104 The crystal grain size is 40nm-55nm, which has both excellent capacity and high temperature stability.

[0057] Since the nickel-cobalt-manganese ternary positive electrode material provided in the present application has both excellent capacity and high-temperature cycle performance, after the nickel-cobalt-manganese ternary positive electrode material is assembled into a lithium-ion battery, the lithium-ion battery has excellent capacity and high-temperature cycle performance.

[0058] In a fourth aspect of the present application, a method for preparing a nickel-cobalt-manganese ternary positive electrode material is provided, comprising the following steps:

[0059] S201, providing the nickel-cobalt-manganese precursor as described above; and

[0060] S202, mixing a nickel-cobalt-manganese precursor and lithium hydroxide in proportion, and performing solid-phase sintering to obtain a nickel-cobalt-manganese ternary positive electrode material; wherein, in the step of performing solid-phase sintering, the sintering temperature is less than or equal to 770°C.

[0061] In one embodiment, the sintering temperature is 730°C-750°C, including but not limited to 730°C, 735°C, 740°C, 745°C or 750°C.

[0062] In one embodiment, in the step of performing solid-phase sintering, the sintering time is 8 hours to 14 hours, including but not limited to 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours or 14 hours.

[0063] Since the half maximum width FWHM of the nickel-cobalt-manganese precursor 101The high temperature is conducive to the diffusion of lithium ions, so the crystallinity of the nickel-cobalt-manganese ternary positive electrode material can be improved at a lower temperature, that is, the grain size of the nickel-cobalt-manganese ternary positive electrode material is increased. Therefore, when the nickel-cobalt-manganese precursor provided by the present application is used to prepare the nickel-cobalt-manganese ternary positive electrode material, the solid-phase sintering temperature can be reduced to below 750°C, effectively reducing the energy consumption cost.

[0064] Hereinafter, the nickel-cobalt-manganese precursor and its preparation method, the nickel-cobalt-manganese ternary positive electrode material and its preparation method will be further described through the following specific examples.

[0065] Example 1

[0066] Nickel sulfate, cobalt sulfate, and manganese sulfate were mixed at a molar ratio of Ni:Co:Mn of 89:4:7 to prepare a metal salt solution. The total concentration of nickel ions, cobalt ions, and manganese ions in the metal salt solution was 133.5 g / L.

[0067] The reactor was protected by nitrogen, and the nitrogen ventilation rate was maintained at 240 L / h. Then, the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia aqueous solution were simultaneously added to the reactor for coprecipitation reaction. During the coprecipitation reaction, the stirring speed of the reactor was controlled at 445 rpm, the pH value was controlled within the range of 10.35±0.1, the ammonia concentration in the reactor was controlled at 6±1 g / L, the reaction temperature was 60°C, and the crystal nucleus particle size D in the solution was controlled. 50 Grow to 10.25μm.

[0068] The reaction solution was centrifuged, the solid was washed with deionized water, dried at about 100 ° C and passed through a 400 mesh sieve to obtain nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2.

[0069] The prepared nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2 and lithium hydroxide in a molar ratio of Li:(Ni 0.89 Co 0.04 Mn 0.07 )=1.05 for dry mixing, and then the mixture is subjected to solid-phase sintering reaction in a pure oxygen atmosphere. The solid-phase sintering reaction temperature is 750° C. and the reaction time is 12 h to obtain a ternary positive electrode material, which is numbered NCM-1.

[0070] Example 2

[0071] Nickel sulfate, cobalt sulfate, and manganese sulfate were mixed at a molar ratio of Ni:Co:Mn of 89:4:7 to prepare a metal salt solution. The total concentration of nickel ions, cobalt ions, and manganese ions in the metal salt solution was 133.5 g / L.

[0072] The reactor was protected by nitrogen, and the nitrogen ventilation rate was maintained at 240 L / h. Then, the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia aqueous solution were simultaneously added to the reactor for coprecipitation reaction. During the coprecipitation reaction, the stirring speed of the reactor was controlled at 445 rpm, the pH value was controlled within the range of 10.60±0.1, the ammonia concentration in the reactor was controlled at 6±1 g / L, the reaction temperature was 55°C, and the crystal nucleus particle size D in the solution was controlled. 50 Grow to 10.25μm.

[0073] The reaction solution was centrifuged, the solid was washed with deionized water, dried at about 100 ° C and passed through a 400 mesh sieve to obtain nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2.

[0074] The prepared nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2 and lithium hydroxide in a molar ratio of Li:(Ni 0.89 Co 0.04 Mn 0.07 )=1.05 for dry mixing, and then the mixture is subjected to solid-phase sintering reaction in a pure oxygen atmosphere. The solid-phase sintering reaction temperature is 750° C. and the reaction time is 12 h to obtain a ternary positive electrode material, which is numbered NCM-2.

[0075] Example 3

[0076] Nickel sulfate, cobalt sulfate, and manganese sulfate were mixed at a molar ratio of Ni:Co:Mn of 89:4:7 to prepare a metal salt solution. The total concentration of nickel ions, cobalt ions, and manganese ions in the metal salt solution was 133.5 g / L.

[0077] The reactor was protected by nitrogen, and the nitrogen ventilation rate was maintained at 240 L / h. Then, the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia aqueous solution were simultaneously added to the reactor for coprecipitation reaction. During the coprecipitation reaction, the stirring speed of the reactor was controlled at 445 rpm, the pH value was controlled within the range of 10.95±0.1, the ammonia concentration in the reactor was controlled at 9±1 g / L, the reaction temperature was 55°C, and the crystal nucleus particle size D in the solution was controlled. 50 Grow to 10.25μm.

[0078] The reaction solution was centrifuged, the solid was washed with deionized water, dried at about 100 ° C and passed through a 400 mesh sieve to obtain nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2.

[0079] The prepared nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2 and lithium hydroxide in a molar ratio of Li:(Ni 0.89 Co 0.04 Mn 0.07 )=1.05 for dry mixing, and then the mixture is subjected to solid-phase sintering reaction in a pure oxygen atmosphere. The solid-phase sintering reaction temperature is 750° C. and the reaction time is 12 h to obtain a ternary positive electrode material, which is numbered NCM-3.

[0080] Example 4

[0081] Nickel sulfate, cobalt sulfate, and manganese sulfate were mixed at a molar ratio of Ni:Co:Mn of 89:4:7 to prepare a metal salt solution. The total concentration of nickel ions, cobalt ions, and manganese ions in the metal salt solution was 133.5 g / L.

[0082] Nitrogen and air were introduced into the reactor, with the nitrogen ventilation rate maintained at 210 L / h and the air ventilation rate maintained at 30 L / h. Then, the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia aqueous solution were simultaneously added into the reactor for coprecipitation reaction. During the coprecipitation reaction, the stirring speed of the reactor was controlled at 445 rpm, the pH value was controlled within the range of 10.35±0.1, the ammonia concentration in the reactor was controlled at 6±1 g / L, the reaction temperature was 60°C, and the crystal nucleus particle size D in the solution was controlled. 50 Grow to 10.25μm.

[0083] The reaction solution was centrifuged, the solid was washed with deionized water, dried at about 100 ° C and passed through a 400 mesh sieve to obtain nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2.

[0084] The prepared nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2 and lithium hydroxide in a molar ratio of Li:(Ni 0.89 Co 0.04 Mn 0.07)=1.05 for dry mixing, and then the mixture is subjected to solid-phase sintering reaction in a pure oxygen atmosphere. The temperature of the solid-phase sintering reaction is 750° C. and the reaction time is 12 h to obtain a ternary positive electrode material, which is numbered NCM-4.

[0085] Example 5

[0086] Nickel sulfate, cobalt sulfate, and manganese sulfate were mixed at a molar ratio of Ni:Co:Mn of 89:4:7 to prepare a metal salt solution. The total concentration of nickel ions, cobalt ions, and manganese ions in the metal salt solution was 133.5 g / L.

[0087] Nitrogen and air were introduced into the reactor, with the nitrogen ventilation rate maintained at 195 L / h and the air ventilation rate maintained at 45 L / h. Then, the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia aqueous solution were simultaneously added into the reactor for coprecipitation reaction. During the coprecipitation reaction, the stirring speed of the reactor was controlled at 445 rpm, the pH value was controlled within the range of 10.35±0.1, the ammonia concentration in the reactor was controlled at 6±1 g / L, the reaction temperature was 60°C, and the crystal nucleus particle size D in the solution was controlled. 50 Grow to 10.25μm.

[0088] The reaction solution was centrifuged, the solid was washed with deionized water, dried at about 100 ° C and passed through a 400 mesh sieve to obtain nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2.

[0089] The prepared nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2 and lithium hydroxide in a molar ratio of Li:(Ni 0.89 Co 0.04 Mn 0.07 )=1.05 for dry mixing, and then the mixture is subjected to solid-phase sintering reaction in a pure oxygen atmosphere. The solid-phase sintering reaction temperature is 750° C. and the reaction time is 12 h to obtain a ternary positive electrode material, which is numbered NCM-1.

[0090] Example 6

[0091] Nickel sulfate, cobalt sulfate, and manganese sulfate were mixed at a molar ratio of Ni:Co:Mn of 89:4:7 to prepare a metal salt solution. The total concentration of nickel ions, cobalt ions, and manganese ions in the metal salt solution was 133.5 g / L.

[0092] The reactor was protected by nitrogen, and the nitrogen ventilation rate was maintained at 240 L / h. Then, the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia aqueous solution were simultaneously added to the reactor for coprecipitation reaction. During the coprecipitation reaction, the stirring speed of the reactor was controlled at 445 rpm, the pH value was controlled within the range of 10.35±0.1, the ammonia concentration in the reactor was controlled at 6±1 g / L, the reaction temperature was 55°C, and the crystal nucleus particle size D in the solution was controlled. 50 Grow to 10.25μm.

[0093] The reaction solution was centrifuged, the solid was washed with deionized water, dried at about 100 ° C and passed through a 400 mesh sieve to obtain nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2.

[0094] The prepared nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2 and lithium hydroxide in a molar ratio of Li:(Ni 0.89 Co 0.04 Mn 0.07 )=1.05 for dry mixing, and then the mixture is subjected to solid-phase sintering reaction in a pure oxygen atmosphere. The solid-phase sintering reaction temperature is 730° C. and the reaction time is 12 h to obtain a ternary positive electrode material numbered NCM-6.

[0095] Example 7

[0096] Nickel sulfate, cobalt sulfate, and manganese sulfate were mixed at a molar ratio of Ni:Co:Mn of 87:6:7 to prepare a metal salt solution. The total concentration of nickel ions, cobalt ions, and manganese ions in the metal salt solution was 133.5 g / L.

[0097] The reactor was protected by nitrogen, and the nitrogen ventilation rate was maintained at 240 L / h. Then, the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia aqueous solution were simultaneously added to the reactor for coprecipitation reaction. During the coprecipitation reaction, the stirring speed of the reactor was controlled at 445 rpm, the pH value was controlled within the range of 10.45±0.1, the ammonia concentration in the reactor was controlled at 6±1 g / L, the reaction temperature was 58°C, and the crystal nucleus particle size D in the solution was controlled. 50 Grow to 10.25μm.

[0098] The reaction solution was centrifuged, the solid was washed with deionized water, dried at about 100 ° C and passed through a 400 mesh sieve to obtain nickel-cobalt-manganese precursor Ni 0.87 Co 0.06 Mn 0.07 (OH)2.

[0099] The prepared nickel-cobalt-manganese precursor Ni 0.87 Co 0.06 Mn 0.07 (OH)2 and lithium hydroxide in a molar ratio of Li:(Ni 0.87 Co 0.06 Mn 0.07 )=1.05 for dry mixing, and then the mixture is subjected to solid-phase sintering reaction in a pure oxygen atmosphere. The solid-phase sintering reaction temperature is 750° C. and the reaction time is 12 h to obtain a ternary positive electrode material, which is numbered NCM-7.

[0100] Example 8

[0101] Nickel sulfate, cobalt sulfate, and manganese sulfate were mixed at a molar ratio of Ni:Co:Mn of 87:6:7 to prepare a metal salt solution. The total concentration of nickel ions, cobalt ions, and manganese ions in the metal salt solution was 133.5 g / L.

[0102] The reactor was protected by nitrogen, and the nitrogen ventilation rate was maintained at 240 L / h. Then, the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia aqueous solution were simultaneously added to the reactor for coprecipitation reaction. During the coprecipitation reaction, the stirring speed of the reactor was controlled at 445 rpm, the pH value was controlled within the range of 10.35±0.1, the ammonia concentration in the reactor was controlled at 8±1 g / L, the reaction temperature was 55°C, and the crystal nucleus particle size D in the solution was controlled. 50 Grow to 10.25μm.

[0103] The reaction solution was centrifuged, the solid was washed with deionized water, dried at about 100 ° C and passed through a 400 mesh sieve to obtain nickel-cobalt-manganese precursor Ni 0.87 Co 0.06 Mn 0.07 (OH)2.

[0104] The prepared nickel-cobalt-manganese precursor Ni 0.87 Co 0.06 Mn 0.07 (OH)2 and lithium hydroxide in a molar ratio of Li:(Ni 0.87 Co 0.06 Mn 0.07 )=1.05 for dry mixing, and then the mixture is subjected to solid-phase sintering reaction in a pure oxygen atmosphere. The solid-phase sintering reaction temperature is 750° C. and the reaction time is 12 h to obtain a ternary positive electrode material, which is numbered NCM-8.

[0105] Comparative Example 1

[0106] Nickel sulfate, cobalt sulfate, and manganese sulfate were mixed at a molar ratio of Ni:Co:Mn of 89:4:7 to prepare a metal salt solution. The total concentration of nickel ions, cobalt ions, and manganese ions in the metal salt solution was 133.5 g / L.

[0107] The reactor was protected by nitrogen, and the nitrogen ventilation rate was maintained at 240 L / h. Then, the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia aqueous solution were simultaneously added to the reactor for coprecipitation reaction. During the coprecipitation reaction, the stirring speed of the reactor was controlled at 445 rpm, the pH value was controlled within the range of 10.20±0.1, the ammonia concentration in the reactor was controlled at 3±1 g / L, the reaction temperature was 50°C, and the crystal nucleus particle size D in the solution was controlled. 50 Grow to 10.25μm.

[0108] The reaction solution was centrifuged, the solid was washed with deionized water, dried at about 100 ° C and passed through a 400 mesh sieve to obtain nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2.

[0109] The prepared nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2 and lithium hydroxide in a molar ratio of Li:(Ni 0.89 Co 0.04 Mn 0.07 )=1.05 for dry mixing, and then the mixture is subjected to solid-phase sintering reaction in a pure oxygen atmosphere. The solid-phase sintering reaction temperature is 750°C and the reaction time is 12h to obtain a ternary positive electrode material, which is numbered NCM-D1.

[0110] Comparative Example 2

[0111] Nickel sulfate, cobalt sulfate, and manganese sulfate were mixed at a molar ratio of Ni:Co:Mn of 89:4:7 to prepare a metal salt solution. The total concentration of nickel ions, cobalt ions, and manganese ions in the metal salt solution was 133.5 g / L.

[0112] The reactor was protected by nitrogen, and the nitrogen ventilation rate was maintained at 240 L / h. Then, the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia aqueous solution were simultaneously added to the reactor for coprecipitation reaction. During the coprecipitation reaction, the stirring speed of the reactor was controlled at 445 rpm, the pH value was controlled within the range of 11.00±0.1, the ammonia concentration in the reactor was controlled at 10±1 g / L, the reaction temperature was 65°C, and the crystal nucleus particle size D in the solution was controlled. 50 Grow to 10.25μm.

[0113] The reaction solution was centrifuged, the solid was washed with deionized water, dried at about 100 ° C and passed through a 400 mesh sieve to obtain nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2.

[0114] The prepared nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2 and lithium hydroxide in a molar ratio of Li:(Ni 0.89 Co 0.04 Mn 0.07 )=1.05 for dry mixing, and then the mixture is subjected to solid-phase sintering reaction in a pure oxygen atmosphere. The solid-phase sintering reaction temperature is 750°C and the reaction time is 12h to obtain a ternary positive electrode material, which is numbered NCM-D2.

[0115] Comparative Example 3

[0116] Nickel sulfate, cobalt sulfate, and manganese sulfate were mixed at a molar ratio of Ni:Co:Mn of 89:4:7 to prepare a metal salt solution. The total concentration of nickel ions, cobalt ions, and manganese ions in the metal salt solution was 133.5 g / L.

[0117] Nitrogen and air were introduced into the reactor, with the nitrogen ventilation rate maintained at 190 L / h and the air ventilation rate maintained at 50 L / h. The metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia aqueous solution were then added to the reactor simultaneously for a coprecipitation reaction. During the coprecipitation reaction, the stirring speed of the reactor was controlled at 445 rpm, the pH value was controlled within the range of 10.35±0.1, the ammonia concentration in the reactor was controlled at 6±1 g / L, the reaction temperature was 60°C, and the crystal nucleus particle size D in the solution was controlled. 50 Grow to 10.25μm.

[0118] The reaction solution was centrifuged, the solid was washed with deionized water, dried at about 100 ° C and passed through a 400 mesh sieve to obtain nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2.

[0119] The prepared nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2 and lithium hydroxide in a molar ratio of Li:(Ni 0.89 Co 0.04 Mn 0.07)=1.05 for dry mixing, and then the mixture is subjected to solid-phase sintering reaction in a pure oxygen atmosphere. The temperature of the solid-phase sintering reaction is 750°C and the reaction time is 12h to obtain a ternary positive electrode material, which is numbered NCM-D3.

[0120] Comparative Example 4

[0121] Nickel sulfate, cobalt sulfate, and manganese sulfate were mixed at a molar ratio of Ni:Co:Mn of 87:6:7 to prepare a metal salt solution. The total concentration of nickel ions, cobalt ions, and manganese ions in the metal salt solution was 133.5 g / L.

[0122] The reactor was protected by nitrogen, and the nitrogen ventilation rate was maintained at 240 L / h. Then, the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia aqueous solution were simultaneously added to the reactor for coprecipitation reaction. During the coprecipitation reaction, the stirring speed of the reactor was controlled at 445 rpm, the pH value was controlled within the range of 10.05±0.1, the ammonia concentration in the reactor was controlled at 6±1 g / L, the reaction temperature was 50°C, and the crystal nucleus particle size D in the solution was controlled. 50 Grow to 10.25μm.

[0123] The reaction solution was centrifuged, the solid was washed with deionized water, dried at about 100 ° C and passed through a 400 mesh sieve to obtain nickel-cobalt-manganese precursor Ni 0.87 Co 0.06 Mn 0.07 (OH)2.

[0124] The prepared nickel-cobalt-manganese precursor Ni 0.87 Co 0.06 Mn 0.07 (OH)2 and lithium hydroxide in a molar ratio of Li:(Ni 0.87 Co 0.06 Mn 0.07 )=1.05 for dry mixing, and then the mixture is subjected to solid-phase sintering reaction in a pure oxygen atmosphere. The solid-phase sintering reaction temperature is 750°C and the reaction time is 12h to obtain a ternary positive electrode material, which is numbered NCM-D4.

[0125] Test Case

[0126] The tap density (TD), specific surface area (SSA), FWHM of the nickel-cobalt-manganese precursors prepared in test examples 1-8 and comparative examples 1-4 were 001 and FWHM 101The specific testing method is as follows, and the test results are shown in Table 1. The half-width test graph of the nickel-cobalt-manganese precursor prepared in Example 1 is shown in Figure 1, the half-width test graph of the nickel-cobalt-manganese precursor prepared in Example 2 is shown in Figure 2, the half-width test graph of the nickel-cobalt-manganese precursor prepared in Example 3 is shown in Figure 3, the half-width test graph of the nickel-cobalt-manganese precursor prepared in Example 4 is shown in Figure 4, the half-width test graph of the nickel-cobalt-manganese precursor prepared in Example 5 is shown in Figure 5, the half-width test graph of the nickel-cobalt-manganese precursor prepared in Comparative Example 1 is shown in Figure 6, the half-width test graph of the nickel-cobalt-manganese precursor prepared in Comparative Example 2 is shown in Figure 7, and the half-width test graph of the nickel-cobalt-manganese precursor prepared in Comparative Example 3 is shown in Figure 8.

[0127] The grain size and electrochemical performance of the ternary cathode materials prepared in Examples 1-8 and Comparative Examples 1-4 were tested. The specific testing methods are shown below, and the test results are shown in Table 2.

[0128] Tap density (TD): The nickel-cobalt-manganese precursor in the container is tapped to measure its mass per unit volume.

[0129] Specific surface area (SSA): measured by low-temperature nitrogen adsorption method.

[0130] FWHM (001) 、FWHM (101) : is the half-peak width corresponding to the (001) and (101) crystal planes of the nickel-cobalt-manganese precursor, which can be directly read using the jade software.

[0131] D 003 Grain size, D 104 Grain size: calculated using Scherrer formula, expression D (x) =Kλ / (βcosθ), D (x) is the crystal grain size of the positive electrode material; K is a constant, taken as 0.89; λ is the X-ray wavelength; β is the half-peak width of the diffraction peak of the positive electrode material; θ is the diffraction angle corresponding to the diffraction peak of the positive electrode material; when calculating D 003 When D is calculated, β is the half-peak width corresponding to the diffraction peak of the (003) crystal plane of the positive electrode material, and θ is the diffraction angle corresponding to the diffraction peak of the (003) crystal plane of the positive electrode material. 104 When β is the half-peak width corresponding to the diffraction peak of the crystal plane of the positive electrode material (104), θ is the diffraction angle corresponding to the diffraction peak of the crystal plane of the positive electrode material (104).

[0132] 0.1C first-week capacity, 1C 50-week cycle retention rate 45℃: Using N-methylpyrrolidone as solvent, the ternary positive electrode material, acetylene black and PVDF were evenly mixed in a mass ratio of 8:1:1, coated on aluminum foil, and dried at 80℃ for 8 hours, and then vacuum-dried at 120℃ for 12 hours; the battery was assembled in an argon-protected glove box, with the negative electrode being a metal lithium sheet, the separator being a polypropylene film, and the electrolyte being 1M LiPF6-EC / DMC (1:1, v / v); the battery was discharged at a rate of 0.1C at a specific cutoff voltage of 3-4.3V to test the first discharge capacity and first efficiency, and then cycled 50 times at a rate of 1C at the same cutoff voltage as in the half-cell test, and the cycle capacity retention rate after 50 cycles was recorded.

[0133] Table 1

[0134] Table 2

[0135] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0136] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A nickel-cobalt-manganese precursor, characterized in that: The molecular formula of the nickel-cobalt-manganese precursor is Ni x Co y Mn (1-x-y) (OH)2, wherein 0<x<1, 0<y<1, x+y<1, the FWHM of the nickel-cobalt-manganese precursor (001) 0.459-0.493, FWHM (101) It is 0.49-0.

552.

2. The nickel-cobalt-manganese precursor according to claim 1, characterized in that The nickel-cobalt-manganese precursor satisfies at least one of the following conditions: (1) The structure of the nickel-cobalt-manganese precursor is a secondary particle ball formed by the agglomeration of primary particles; (2) The tap density of the nickel-cobalt-manganese precursor is 1.95 g / cm 3 -2.00g / cm 3 ; (3) The specific surface area of ​​the nickel-cobalt-manganese precursor is 6.22 m 2 / g-8.36m 2 / g; (4) D of the nickel-cobalt-manganese precursor 50 The particle size is 8μm-13μm.

3. A method for preparing a nickel-cobalt-manganese precursor according to claim 1 or 2, characterized in that: The following steps are involved: The nickel salt, cobalt salt and manganese salt are prepared into a metal salt solution in proportion; and the metal salt solution, alkali solution and ammonia solution are mixed to carry out a coprecipitation reaction. When the D 50 After the particle size reaches the target size, the reaction is completed to obtain the nickel-cobalt-manganese precursor; wherein, in the step of coprecipitation reaction, the nitrogen ventilation rate is 195L / min-240L / min, the ammonia concentration is 6g / L-9g / L, the pH value of the reaction liquid is 10.35-10.95, and the temperature is 55°C-60°C.

4. The method for preparing a nickel-cobalt-manganese precursor according to claim 3, wherein: During the coprecipitation reaction step, air is introduced at the same time, and the air ventilation volume is 30L / min-45L / min.

5. The method for preparing a nickel-cobalt-manganese precursor according to claim 3, wherein: The coprecipitation reaction is carried out under stirring conditions, and the stirring speed is 200 rpm-500 rpm.

6. The method for preparing a nickel-cobalt-manganese precursor according to claim 3, wherein: The molar ratio of nickel ions, cobalt ions and manganese ions in the metal salt solution is (85-90):(3-6):(4-12); and / or the alkali solution is a sodium hydroxide aqueous solution.

7. The method for preparing a nickel-cobalt-manganese precursor according to claim 3, wherein: The total concentration of nickel ions, cobalt ions and manganese ions in the metal salt solution is 100 g / L-150 g / L.

8. A nickel-cobalt-manganese ternary positive electrode material, characterized in that: The nickel-cobalt-manganese ternary positive electrode material is prepared by solid-phase sintering the nickel-cobalt-manganese precursor according to claim 1 or 2, and the D of the nickel-cobalt-manganese ternary positive electrode material is 003 The crystal grain size is 80nm-115nm, D 104 The crystal grain size is 40nm-55nm.

9. A method for preparing the nickel-cobalt-manganese ternary positive electrode material according to claim 8, characterized in that: The following steps are involved: Providing the nickel-cobalt-manganese precursor according to claim 1 or 2; as well as The nickel-cobalt-manganese precursor is mixed with lithium hydroxide in proportion and solid-phase sintered to obtain a nickel-cobalt-manganese ternary positive electrode material, wherein in the step of solid-phase sintering, the sintering temperature is less than or equal to 770°C.

10. The method for preparing the nickel-cobalt-manganese ternary positive electrode material according to claim 9, characterized in that: In the step of solid phase sintering, the sintering time is 8h-14h.

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