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

Abstract

The present application relates to a kind of nickel cobalt manganese precursor and its preparation method, nickel cobalt manganese ternary positive electrode material and its preparation method, the molecular formula of the nickel cobalt manganese precursor is Ni x Co y Mn (1‑x‑y) (OH)2, wherein 0 (001) The FWHM of the nickel cobalt manganese precursor is 0.459-0.493, and the FWHM (101) It is 0.49-0.552. The nickel cobalt manganese ternary positive electrode material is prepared using the nickel cobalt manganese precursor, and the D 003 Crystal grain size of the nickel cobalt manganese ternary positive electrode material is 80nm-115nm, and the D 104 Crystal grain size is 40nm-55nm, and the nickel cobalt manganese ternary positive electrode material has excellent capacity and high temperature cycle performance, and is prepared at lower temperature, effectively reduces energy consumption cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium batteries, in particular to a nickel-cobalt-manganese precursor and a preparation method thereof, and a nickel-cobalt-manganese ternary positive electrode material and a preparation method thereof. BACKGROUND

[0002] The lithium battery industry has become a mainstay in the new energy industry after years of development, and the preparation of high-performance positive electrode materials is undoubtedly the research focus in the upstream and downstream industrial chains. Research shows that if the grain size of the nickel-cobalt-manganese ternary positive electrode material is too small, the crystallinity of the nickel-cobalt-manganese ternary positive electrode material is insufficient, and if the grain size is too large, the nickel-cobalt-manganese ternary positive electrode material is single-crystallized; whether the crystallinity is insufficient or single-crystallized, it will lead to a decrease in capacity or high-temperature cycle performance.

[0003] Therefore, the traditional technical solution usually adjusts the grain size by adjusting the lithium content or doping elements, so that the nickel-cobalt-manganese ternary positive electrode material has better capacity or high-temperature cycle performance, however, the above methods need to make a choice between capacity and high-temperature cycle performance, when the grain size decreases, the crystallinity of the nickel-cobalt-manganese ternary positive electrode material becomes poor, the capacity decreases, but the high-temperature cycle performance is good; when the grain size increases, the crystallinity of the nickel-cobalt-manganese ternary positive electrode material is good, the capacity is high, but the first discharge capacity is low, and the high-temperature cycle performance needs to be improved.

[0004] Therefore, it is urgent to develop a low-energy-consumption preparation method that can make the nickel-cobalt-manganese ternary positive electrode material have excellent capacity and high-temperature cycle performance. SUMMARY

[0005] Therefore, it is necessary to provide a nickel-cobalt-manganese precursor and a preparation method thereof, and a nickel-cobalt-manganese ternary positive electrode material and a preparation method thereof, so that the nickel-cobalt-manganese ternary positive electrode material has excellent capacity and high-temperature cycle performance when the nickel-cobalt-manganese ternary positive electrode material is prepared by using the nickel-cobalt-manganese precursor, and the nickel-cobalt-manganese ternary positive electrode material can be prepared at a lower temperature, thereby effectively reducing the energy consumption cost.

[0006] The present application discloses a nickel-cobalt-manganese precursor, the molecular formula of the nickel-cobalt-manganese precursor is Ni x Co y Mn (1-x-y) (OH)2, wherein 0 (001) The FWHM of the nickel-cobalt-manganese precursor is 0.459-0.493, and the FWHM (101) is 0.49-0.552.

[0007] In an embodiment, the nickel-cobalt-manganese precursor satisfies at least one of the following conditions:

[0008] (1) the structure of the nickel-cobalt-manganese precursor is a secondary particle ball formed by agglomeration of primary particles;

[0009] (2) the tap density of the nickel-cobalt-manganese precursor is 1.95 g / cm 3 -2.00 g / cm 3 ;

[0010] (3) the specific surface area of the nickel-cobalt-manganese precursor is 6.22 m 2 / g-8.36 m 2 / g;

[0011] (4) the D 50 50 particle size of the nickel-cobalt-manganese precursor is 8 μm-13 μm.

[0012] A preparation method of the nickel-cobalt-manganese precursor as described above, comprising the following steps:

[0013] proportioning nickel salt, cobalt salt and manganese salt into a metal salt solution; and mixing the metal salt solution, lye and ammonia solution to perform a co-precipitation reaction, and the reaction is completed when the D 50 50 particle size of the product reaches a target size, to obtain the nickel-cobalt-manganese precursor; wherein in the step of performing the co-precipitation reaction, the air flow is 195 L / min-240 L / min, the ammonia concentration is 6 g / L-9 g / L, the pH of the reaction solution is 10.35-10.95, and the temperature is 55°C-60°C.

[0014] In an embodiment, in the step of performing the co-precipitation reaction, air is also introduced, and the air flow is 30 L / min-45 L / min.

[0015] In an embodiment, the co-precipitation reaction is performed under stirring, and the stirring speed is 200 rpm-500 rpm.

[0016] In an embodiment, the molar ratio of nickel ions, cobalt ions and manganese ions in the metal salt solution is (85-90):(3-6):(4-12).

[0017] In an embodiment, the total concentration of nickel ions, cobalt ions and manganese ions in the metal salt solution is 100 g / L-150 g / L.

[0018] A nickel-cobalt-manganese ternary positive electrode material, which is prepared from the nickel-cobalt-manganese precursor as described above through solid-phase sintering, and the D 003 50 crystal face grain size of the nickel-cobalt-manganese ternary positive electrode material is 80 nm-115 nm, the D 104 50 crystal face grain size is 40 nm-55 nm.

[0019] A preparation method of the nickel-cobalt-manganese ternary positive electrode material as described above, comprising the following steps:

[0020] provide the nickel-cobalt-manganese precursor as described above; and

[0021] mixing the nickel-cobalt-manganese precursor with lithium hydroxide in a certain proportion, and performing solid-phase sintering to obtain a nickel-cobalt-manganese ternary positive electrode material, wherein the sintering temperature in the step of performing solid-phase sintering is less than or equal to 770℃.

[0022] In an embodiment, the sintering time in the step of performing solid-phase sintering is 8h-14h.

[0023] The nickel-cobalt-manganese precursor provided by the present application has a FWHM (001) of 0.459-0.493, a FWHM (101) of 0.49-0.552, and the mass of lithium element entering the nickel-cobalt-manganese precursor can be accurately controlled in the step of performing solid-phase sintering, so that the D 003 crystal grain size of the nickel-cobalt-manganese ternary positive electrode material is 80nm-115nm, and the D 104 crystal grain size is 40nm-55nm, so that the nickel-cobalt-manganese ternary positive electrode material has a suitable crystallinity, and further has excellent capacity and high-temperature cycle performance. In addition, the FWHM 101 of the nickel-cobalt-manganese precursor is high, which is beneficial to the diffusion of lithium ions, so that the crystallinity of the nickel-cobalt-manganese ternary positive electrode material can be improved at a lower temperature, i.e. the crystal grain size of the nickel-cobalt-manganese ternary positive electrode material is increased, so that when the nickel-cobalt-manganese ternary positive electrode material is prepared by using the nickel-cobalt-manganese precursor provided by the present application, the solid-phase sintering temperature is reduced to below 770℃, and the energy consumption cost is effectively reduced. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0025] Figure 1 the half-peak width test graph of the nickel-cobalt-manganese precursor prepared for Example 1;

[0026] Figure 2 the half-peak width test graph of the nickel-cobalt-manganese precursor prepared for Example 2;

[0027] Figure 3 the half-peak width test graph of the nickel-cobalt-manganese precursor prepared for Example 3;

[0028] Figure 4A half peak width test chart of the nickel cobalt manganese precursor prepared for Example 4;

[0029] Figure 5 A half peak width test chart of the nickel cobalt manganese precursor prepared for Example 5;

[0030] Figure 6 A half peak width test chart of the nickel cobalt manganese precursor prepared for Comparative Example 1;

[0031] Figure 7 A half peak width test chart of the nickel cobalt manganese precursor prepared for Comparative Example 2;

[0032] Figure 8 A half peak width test chart of the nickel cobalt manganese precursor prepared for Comparative Example 3;

[0033] Figure 9 A half peak width test chart of the nickel cobalt manganese precursor prepared for Comparative Example 4. DETAILED DESCRIPTION

[0034] In order to facilitate the 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 realized 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 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 commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments or examples only and is not intended to be limiting of the application.

[0036] In a 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, wherein 0 (001) is 0.459-0.493, the FWHM (101) is 0.49-0.552.

[0037] It can be understood that the FWHM (001) refers to the half peak width corresponding to the (001) crystal face diffraction peak of the nickel cobalt manganese precursor, and the FWHM (101) refers to the half peak width corresponding to the (101) crystal face diffraction peak of the nickel cobalt manganese precursor.

[0038] The present application finds that when the FWHM (001)The range is 0.459-0.493, FWHM (101) When the concentration is 0.49-0.552, the mass of lithium entering the nickel-cobalt-manganese precursor can be precisely controlled during the solid-state sintering step, thereby improving the D of the nickel-cobalt-manganese ternary cathode material. 003 The crystal grain size is 90nm-115nm, D 104 The crystal grain size is 45nm-55nm, which gives the nickel-cobalt-manganese ternary cathode material a suitable degree of crystallinity, thus enabling the nickel-cobalt-manganese ternary cathode material to have both excellent capacity and high-temperature cycling performance.

[0039] FMWH of nickel-cobalt-manganese precursors (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) The range is 0.49-0.552, including but 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 m². 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 / g.

[0041] Understandably, since nickel-cobalt-manganese ternary cathode materials have good inheritance in terms of tap density, particle size, and morphology of nickel-cobalt-manganese precursors, in order to improve the volumetric energy density of the battery by increasing the tap density of the nickel-cobalt-manganese precursor; in one embodiment, the tap density of the nickel-cobalt-manganese precursor is 1.95 g / cm³. 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 50Particle size is 8-13 μm; including but not limited to 8 μm, 9 μm, 10 μm, 11 μm, 12 μm or 13 μm.

[0043] In an embodiment, the structure of the nickel-cobalt-manganese precursor is a secondary particle ball formed by agglomeration of primary particles.

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

[0045] S101, proportionally configuring nickel salt, cobalt salt and manganese salt into a metal salt solution; and

[0046] S102, mixing the metal salt solution, lye and ammonia solution to perform a co-precipitation reaction, and when the D50 of the product is 8-13 μm, the reaction is completed to obtain the nickel-cobalt-manganese precursor. 50 After the particle size reaches the target size, the reaction is completed to obtain the nickel-cobalt-manganese precursor.

[0047] The preparation method of the nickel-cobalt-manganese precursor provided by the present application can accurately control the nitrogen flow rate, ammonia value, pH and temperature of the reaction solution in the co-precipitation reaction process, so that the specific surface area of the nickel-cobalt-manganese precursor is 6.22-8.36 m 2 / g, the FWHM is 0.49-0.552, and the D50 is 8-13 μm. 2 101 Specifically, in the step of co-precipitation reaction, the nitrogen flow rate is 195-240 L / min, including but not limited to 195 L / min, 200 L / min, 205 L / min, 210 L / min, 215 L / min, 220 L / min, 225 L / min, 230 L / min, 235 L / min or 240 L / min, the ammonia concentration is 6-9 g / L, including but not limited to 6 g / L, 7 g / L, 8 g / L or 9 g / 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 55-60℃, including but not limited to 55℃, 56℃, 57℃, 58℃, 59℃ or 60℃.

[0048] In the step S101, 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 selected from nickel sulfate; the cobalt salt includes at least one of cobalt sulfate, cobalt chloride, cobalt nitrate or cobalt acetate, preferably selected from cobalt sulfate; and the manganese salt includes at least one of manganese sulfate, manganese chloride, manganese nitrate or manganese acetate, preferably selected from manganese sulfate.

[0049] ​By controlling the molar ratio between nickel ions, cobalt ions and manganese ions, nickel-cobalt-manganese precursors with different proportions can be prepared, and in an 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 total concentration of metal ions in the metal salt solution, the growth rate of the nickel-cobalt-manganese precursor can be controlled, and in an embodiment, the total concentration of nickel ions, cobalt ions and manganese ions in the metal salt solution is 100g / L-150g / L, including but not limited to 100g / L, 110g / L, 120g / L, 130g / L, 140g / L or 150g / L.

[0051] In step S102, air can also be introduced simultaneously during the co-precipitation reaction step, and the air flow rate is 30L / min-45L / min, including but not limited to 30L / min, 35L / min, 40L / min or 45L / min.

[0052] In an embodiment, the co-precipitation reaction is carried out under stirring conditions, and during the co-precipitation reaction, the fluid shear force can be improved by stirring to prevent particle adhesion and clump growth, and the diffusion of solute ions can be accelerated to prevent local high supersaturation, thereby obtaining crystal seed particles with more uniform particle size and better dispersity; preferably, the stirring speed is 200rpm-500rpm, including but not limited to 200rpm, 300rpm, 400rpm or 500rpm.

[0053] In a 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 003 The crystal face grain size is 80nm-115nm, the D 104 The crystal face grain size is 40nm-55nm.

[0054] Since the nickel-cobalt-manganese ternary positive electrode material provided by the present application has 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.

[0055] In a fourth aspect of the present application, a preparation method of a nickel-cobalt-manganese ternary positive electrode material is provided, which comprises the following steps:

[0056] S201, providing a nickel-cobalt-manganese precursor as described above; and

[0057] S202, a nickel-cobalt-manganese precursor is mixed with lithium hydroxide in a certain proportion and then solid-state sintered to obtain a nickel-cobalt-manganese ternary cathode material; wherein, in the solid-state sintering step, the sintering temperature is less than or equal to 770℃.

[0058] 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.

[0059] In one embodiment, the solid-state sintering step is carried out for a sintering time of 8h-14h; including but not limited to 8h, 9h, 10h, 11h, 12h, 13h or 14h.

[0060] Due to the full width at half maximum (FWHM) of nickel-cobalt-manganese precursors 101 The high temperature of the precursor is conducive to the diffusion of lithium ions, thus it can improve the crystallinity of the nickel-cobalt-manganese ternary cathode material at a lower temperature, that is, increase the grain size of the nickel-cobalt-manganese ternary cathode material. Therefore, when preparing nickel-cobalt-manganese ternary cathode material using the nickel-cobalt-manganese precursor provided by this invention, the solid-state sintering temperature can be reduced to below 750°C, effectively reducing energy consumption costs.

[0061] The following specific examples will further illustrate the nickel-cobalt-manganese precursor and its preparation method, as well as the nickel-cobalt-manganese ternary cathode material and its preparation method.

[0062] Example 1

[0063] Nickel sulfate, cobalt sulfate, and manganese sulfate were mixed in a 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.

[0064] The reactor was protected with nitrogen at a flow rate of 240 L / h. Then, a metal salt solution, a 200 g / L sodium hydroxide aqueous solution, and a 9% ammonia aqueous solution were simultaneously added to the reactor for a co-precipitation reaction. During the co-precipitation reaction, the stirring speed 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℃, and the crystal nucleus size D in the solution was controlled. 50 It grew to 10.25 μm.

[0065] The reaction solution was centrifuged, the resulting solid was washed with deionized water, dried at approximately 100°C, and passed through a 400-mesh sieve to obtain the nickel-cobalt-manganese precursor Ni. 0.89 Co 0.04 Mn 0.07 (OH)2.

[0066] The prepared nickel-cobalt-manganese precursor Ni 0.89Co 0.04 Mn 0.07 (OH)2and lithium hydroxide in a molar ratio Li:(Ni 0.89 Co 0.04 Mn 0.07 ) = 1.05, and then the mixture is subjected to a solid-phase sintering reaction under a pure oxygen atmosphere, the temperature of the solid-phase sintering reaction being 750°C and the reaction time being 12 h, to obtain a ternary positive electrode material, numbered NCM-1.

[0067] Example 2

[0068] Nickel sulfate, cobalt sulfate and manganese sulfate are mixed in a molar ratio 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 being 133.5 g / L.

[0069] The reaction kettle is protected by nitrogen, the nitrogen flow being maintained at 240 L / h, and then the metal salt solution, a 200 g / L aqueous sodium hydroxide solution and a 9% aqueous ammonia solution are simultaneously added to the reaction kettle to perform a co-precipitation reaction, the stirring speed of the reaction kettle being controlled at 445 rpm, the pH value being controlled within a range of 10.60±0.1, the ammonia concentration in the reaction kettle being controlled at 6±1 g / L, and the reaction temperature being 55°C, the crystal nucleus particle size D 50 being controlled in the solution to be 10.25 μm.

[0070] The reaction liquid is subjected to centrifugal treatment, the obtained solid is washed with deionized water, dried at about 100°C and sieved through a 400-mesh sieve to obtain a nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2.

[0071] The prepared nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2and lithium hydroxide are dry-mixed in a molar ratio Li:(Ni 0.89 Co 0.04 Mn 0.07 ) = 1.05, and then the mixture is subjected to a solid-phase sintering reaction under a pure oxygen atmosphere, the temperature of the solid-phase sintering reaction being 750°C and the reaction time being 12 h, to obtain a ternary positive electrode material, numbered NCM-2.

[0072] Example 3

[0073] Nickel sulfate, cobalt sulfate and manganese sulfate are mixed in a molar ratio 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 being 133.5 g / L.

[0074] The reaction kettle is protected by nitrogen, and the nitrogen flow rate is kept at 240 L / h. Then the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia solution are simultaneously added into the reaction kettle for co-precipitation reaction. During the co-precipitation reaction, the stirring speed of the reaction kettle is controlled at 445 rpm, the pH value is controlled within the range of 10.95±0.1, the ammonia concentration in the reaction kettle is controlled at 9±1 g / L, the reaction temperature is 55℃, and the crystal nucleus particle size D 50 grows to 10.25 μm.

[0075] The reaction solution is subjected to centrifugal treatment, the obtained solid is washed with deionized water, dried at about 100℃ and sieved through a 400-mesh screen to obtain a nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2.

[0076] The prepared nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2 and lithium hydroxide are dry-mixed in a molar ratio Li:(Ni 0.89 Co 0.04 Mn 0.07 )=1.05, and then the mixture is subjected to solid-phase sintering reaction under a pure oxygen atmosphere, the solid-phase sintering reaction temperature is 750℃, and the reaction time is 12 h to obtain a ternary positive electrode material, numbered as NCM-3.

[0077] Example 4

[0078] Nickel sulfate, cobalt sulfate and manganese sulfate are mixed in a molar ratio of Ni:Co:Mn 89:4:7 to prepare a metal salt solution, and the total concentration of nickel ions, cobalt ions and manganese ions in the metal salt solution is 133.5 g / L.

[0079] Nitrogen and air are introduced into the reaction kettle, the nitrogen flow rate is kept at 210 L / h, and the air flow rate is kept at 30 L / h. Then the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia solution are simultaneously added into the reaction kettle for co-precipitation reaction. During the co-precipitation reaction, the stirring speed of the reaction kettle is controlled at 445 rpm, the pH value is controlled within the range of 10.35±0.1, the ammonia concentration in the reaction kettle is controlled at 6±1 g / L, the reaction temperature is 60℃, and the crystal nucleus particle size D 50 grows to 10.25 μm.

[0080] The reaction solution is subjected to centrifugal treatment, the obtained solid is washed with deionized water, dried at about 100℃ and sieved through a 400-mesh screen to obtain a nickel-cobalt-manganese precursor Ni 0.89 Co0.04 Mn 0.07 (OH)2.

[0081] The prepared nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2and lithium hydroxide are dry mixed in a molar ratio Li:(Ni 0.89 Co 0.04 Mn 0.07 ) = 1.05, and then the mixture is subjected to a solid-phase sintering reaction under a pure oxygen atmosphere, the temperature of the solid-phase sintering reaction is 750 DEG C, and the reaction time is 12 h, to obtain a ternary positive electrode material, numbered NCM-4.

[0082] Example 5

[0083] Nickel sulfate, cobalt sulfate and manganese sulfate are mixed in a molar ratio 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 being 133.5 g / L.

[0084] Nitrogen and air are introduced into the reaction kettle, the nitrogen flow rate is maintained at 195 L / h, and the air flow rate is maintained at 45 L / h, then the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia solution are simultaneously added to the reaction kettle for co-precipitation reaction, in the process of the co-precipitation reaction, the stirring speed of the reaction kettle is controlled at 445 rpm, the pH value is controlled within the range of 10.35+0.1, the ammonia concentration in the reaction kettle is controlled at 6+1 g / L, and the reaction temperature is 60 DEG C, the crystal nucleus particle size D 50 is controlled to be 10.25 pm.

[0085] The reaction solution is subjected to centrifugal treatment, the obtained solid is washed with deionized water, dried at about 100 DEG C and sieved through a 400-mesh screen, to obtain a nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2.

[0086] The prepared nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2and lithium hydroxide are dry mixed in a molar ratio Li:(Ni 0.89 Co 0.04 Mn 0.07 ) = 1.05, and then the mixture is subjected to a solid-phase sintering reaction under a pure oxygen atmosphere, the temperature of the solid-phase sintering reaction is 750 DEG C, and the reaction time is 12 h, to obtain a ternary positive electrode material, numbered NCM-1.

[0087] Example 6

[0088] Nickel sulfate, cobalt sulfate and manganese sulfate were mixed according to the molar ratio of Ni:Co:Mn 89:4:7 to prepare a metal salt solution, and the total concentration of nickel ions, cobalt ions and manganese ions in the metal salt solution was 133.5 g / L.

[0089] The reaction kettle was protected by nitrogen, and the nitrogen flow rate was maintained at 240 L / h. Then the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia solution were simultaneously added into the reaction kettle for co-precipitation reaction. During the co-precipitation reaction, the stirring speed of the reaction kettle was controlled at 445 rpm, the pH value was controlled within the range of 10.35±0.1, the ammonia concentration in the reaction kettle was controlled at 6±1 g / L, the reaction temperature was 55°C, and the crystal nucleus particle size D 50 grew to 10.25 μm.

[0090] The reaction solution was centrifuged, the obtained solid was washed with deionized water, dried at about 100°C and sieved through a 400 mesh screen to obtain a nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2.

[0091] The prepared nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2 and lithium hydroxide were dry mixed according to the molar ratio Li:(Ni 0.89 Co 0.04 Mn 0.07 )=1.05, and then the mixture was subjected to solid phase sintering reaction under pure oxygen atmosphere, the solid phase sintering reaction temperature was 730°C, and the reaction time was 12 h to obtain a ternary positive electrode material, numbered as NCM-6.

[0092] Example 7

[0093] Nickel sulfate, cobalt sulfate and manganese sulfate were mixed according to the molar ratio of Ni:Co:Mn 87:6:7 to prepare a metal salt solution, and the total concentration of nickel ions, cobalt ions and manganese ions in the metal salt solution was 133.5 g / L.

[0094] The reaction kettle was protected by nitrogen, and the nitrogen flow rate was maintained at 240 L / h. Then the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia solution were simultaneously added into the reaction kettle for co-precipitation reaction. During the co-precipitation reaction, the stirring speed of the reaction kettle was controlled at 445 rpm, the pH value was controlled within the range of 10.45±0.1, the ammonia concentration in the reaction kettle was controlled at 6±1 g / L, the reaction temperature was 58°C, and the crystal nucleus particle size D 50 grew to 10.25 μm.

[0095] The reaction solution was centrifuged, the obtained solid was washed with deionized water, dried at about 100°C and sieved through a 400-mesh screen to obtain a nickel-cobalt-manganese precursor Ni 0.87 Co 0.06 Mn 0.07 (OH)2.

[0096] The prepared nickel-cobalt-manganese precursor Ni 0.87 Co 0.06 Mn 0.07 (OH)2was dry-mixed with lithium hydroxide at a molar ratio Li:(Ni 0.87 Co 0.06 Mn 0.07 ) = 1.05, and then the mixture was subjected to a solid-phase sintering reaction under a pure oxygen atmosphere, the solid-phase sintering reaction was carried out at a temperature of 750°C for 12 h to obtain a ternary positive electrode material, numbered NCM-7.

[0097] Example 8

[0098] Nickel sulfate, cobalt sulfate and manganese sulfate were mixed at a molar ratio of Ni:Co:Mn = 87:6:7 to prepare a metal salt solution, and the total concentration of nickel ions, cobalt ions and manganese ions in the metal salt solution was 133.5 g / L.

[0099] The reaction kettle was protected by nitrogen, and the nitrogen flow rate was maintained at 240 L / h, then the metal salt solution, 200 g / L sodium hydroxide solution and 9% ammonia solution were simultaneously added to the reaction kettle for co-precipitation reaction, during the co-precipitation reaction, the stirring speed of the reaction kettle was controlled at 445 rpm, the pH value was controlled within the range of 10.35±0.1, the ammonia concentration in the reaction kettle was controlled at 8±1 g / L, and the reaction temperature was 55°C, and the crystal nucleus particle size D 50 was controlled to be 10.25 μm.

[0100] The reaction solution was centrifuged, the obtained solid was washed with deionized water, dried at about 100°C and sieved through a 400-mesh screen to obtain a nickel-cobalt-manganese precursor Ni 0.87 Co 0.06 Mn 0.07 (OH)2.

[0101] The prepared nickel-cobalt-manganese precursor Ni 0.87 Co 0.06 Mn 0.07 (OH)2was dry-mixed with lithium hydroxide at a molar ratio Li:(Ni 0.87 Co 0.06 Mn 0.07The prepared nickel-cobalt-manganese precursor Ni Co Mn (OH) 2 and lithium hydroxide are dry-mixed in a molar ratio of Li:(Ni Co Mn) = 1.05, and then the mixture is subjected to a solid-phase sintering reaction under a pure oxygen atmosphere, with a solid-phase sintering reaction temperature of 750°C and a reaction time of 12 h, to obtain a ternary positive electrode material, numbered NCM-8.

[0102] Comparative Example 1

[0103] Nickel sulfate, cobalt sulfate, and manganese sulfate are mixed in a molar ratio of Ni:Co:Mn = 89:4:7 to prepare a metal salt solution, with a total concentration of nickel ions, cobalt ions, and manganese ions in the metal salt solution being 133.5 g / L.

[0104] The reaction kettle is protected by nitrogen, with a nitrogen flow rate being maintained at 240 L / h, and then the metal salt solution, a 200 g / L sodium hydroxide aqueous solution, and a 9% ammonia aqueous solution are simultaneously added to the reaction kettle for a co-precipitation reaction, with a stirring speed of the reaction kettle being controlled at 445 rpm, a pH value being controlled within a range of 10.20 ± 0.1, an ammonia concentration in the reaction kettle being controlled at 3 ± 1 g / L, and a reaction temperature being 50°C, to control the crystal nucleus particle size D 50 grown to 10.25 μm.

[0105] The reaction solution is subjected to centrifugal treatment, the obtained solid is washed with deionized water, dried at about 100°C, and sieved through a 400-mesh screen, to obtain a nickel-cobalt-manganese precursor Ni Co Mn (OH) 2. 0.89 Co 0.04 Mn 0.07 (OH) 2.

[0106] The prepared nickel-cobalt-manganese precursor Ni Co Mn (OH) 2 and lithium hydroxide are dry-mixed in a molar ratio of Li:(Ni Co Mn) = 1.05, and then the mixture is subjected to a solid-phase sintering reaction under a pure oxygen atmosphere, with a solid-phase sintering reaction temperature of 750°C and a reaction time of 12 h, to obtain a ternary positive electrode material, numbered NCM-8. 0.89 Co 0.04 Mn 0.07 (OH) 2. 0.89 Co 0.04 Mn 0.07 The prepared nickel-cobalt-manganese precursor Ni Co Mn (OH) 2 and lithium hydroxide are dry-mixed in a molar ratio of Li:(Ni Co Mn) = 1.05, and then the mixture is subjected to a solid-phase sintering reaction under a pure oxygen atmosphere, with a solid-phase sintering reaction temperature of 750°C and a reaction time of 12 h, to obtain a ternary positive electrode material, numbered NCM-8.

[0107] Comparative Example 2

[0108] Nickel sulfate, cobalt sulfate, and manganese sulfate are mixed in a molar ratio of Ni:Co:Mn = 89:4:7 to prepare a metal salt solution, with a total concentration of nickel ions, cobalt ions, and manganese ions in the metal salt solution being 133.5 g / L.

[0109] The reaction kettle is protected by nitrogen, and the nitrogen flow rate is kept at 240 L / h. Then the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia solution are simultaneously added into the reaction kettle for co-precipitation reaction. During the co-precipitation reaction, the stirring speed of the reaction kettle is controlled at 445 rpm, the pH value is controlled within the range of 11.00±0.1, the ammonia concentration in the reaction kettle is controlled at 10±1 g / L, and the reaction temperature is 65℃. The crystal nucleus particle size D 50 grows to 10.25 μm.

[0110] The reaction solution is subjected to centrifugal treatment, the obtained solid is washed with deionized water, dried at about 100℃ and sieved through a 400 mesh screen to obtain a nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2.

[0111] The prepared nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2and lithium hydroxide are dry-mixed in a molar ratio Li:(Ni 0.89 Co 0.04 Mn 0.07 )=1.05, and then the mixture is subjected to solid-phase sintering reaction under a pure oxygen atmosphere, the solid-phase sintering reaction temperature is 750℃, and the reaction time is 12 h to obtain a ternary positive electrode material, numbered as NCM-D2.

[0112] Comparative Example 3

[0113] Nickel sulfate, cobalt sulfate and manganese sulfate are mixed in a molar ratio of Ni:Co:Mn 89:4:7 to prepare a metal salt solution, and the total concentration of nickel ions, cobalt ions and manganese ions in the metal salt solution is 133.5 g / L.

[0114] Nitrogen and air are introduced into the reaction kettle, the nitrogen flow rate is kept at 190 L / h, and the air flow rate is kept at 50 L / h. Then the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia solution are simultaneously added into the reaction kettle for co-precipitation reaction. During the co-precipitation reaction, the stirring speed of the reaction kettle is controlled at 445 rpm, the pH value is controlled within the range of 10.35±0.1, the ammonia concentration in the reaction kettle is controlled at 6±1 g / L, and the reaction temperature is 60℃. The crystal nucleus particle size D 50 grows to 10.25 μm.

[0115] The reaction solution is subjected to centrifugal treatment, the obtained solid is washed with deionized water, dried at about 100℃ and sieved through a 400 mesh screen to obtain a nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn0.07 (OH)2.

[0116] The prepared nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2and lithium hydroxide are dry mixed in a molar ratio Li:(Ni 0.89 Co 0.04 Mn 0.07 ) = 1.05, and then the mixture is subjected to a solid-phase sintering reaction under a pure oxygen atmosphere, the temperature of the solid-phase sintering reaction is 750 DEG C, and the reaction time is 12 h, to obtain a ternary positive electrode material, numbered NCM-D3.

[0117] Comparative Example 4

[0118] Nickel sulfate, cobalt sulfate and manganese sulfate are mixed in a molar ratio of Ni:Co:Mn 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 is 133.5 g / L.

[0119] The reaction kettle is protected by nitrogen, the nitrogen flow rate is maintained at 240 L / h, and then the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia solution are simultaneously added to the reaction kettle for co-precipitation reaction, in the process of co-precipitation reaction, the stirring speed of the reaction kettle is controlled at 445 rpm, the pH value is controlled within the range of 10.35+0.1, the ammonia concentration in the reaction kettle is controlled at 6+1 g / L, and the reaction temperature is 60 DEG C, the crystal nucleus particle size D 50 is controlled to be 10.25 pm.

[0120] The reaction solution is subjected to centrifugal treatment, the obtained solid is washed with deionized water, dried at about 100 DEG C and sieved through a 400 mesh screen, to obtain a nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2.

[0121] The prepared nickel-cobalt-manganese precursor Ni 0.89 Co 0.04 Mn 0.07 (OH)2and lithium hydroxide are dry mixed in a molar ratio Li:(Ni 0.89 Co 0.04 Mn 0.07 ) = 1.05, and then the mixture is subjected to a solid-phase sintering reaction under a pure oxygen atmosphere, the temperature of the solid-phase sintering reaction is 760 DEG C, and the reaction time is 12 h, to obtain a ternary positive electrode material, numbered NCM-D4.

[0122] Comparative Example 5

[0123] Nickel sulfate, cobalt sulfate and manganese sulfate were mixed according to a molar ratio of Ni:Co:Mn of 87:6:7 to prepare a metal salt solution, and the total concentration of nickel ions, cobalt ions and manganese ions in the metal salt solution was 133.5 g / L.

[0124] The reaction kettle was protected by nitrogen, and the nitrogen flow rate was maintained at 240 L / h. Then the metal salt solution, 200 g / L sodium hydroxide aqueous solution and 9% ammonia solution were simultaneously added to the reaction kettle for co-precipitation reaction. During the co-precipitation reaction, the stirring speed of the reaction kettle was controlled at 445 rpm, the pH value was controlled within the range of 10.05±0.1, the ammonia concentration in the reaction kettle was controlled at 6±1 g / L, and the reaction temperature was 50°C. The crystal nucleus particle size D 50 was controlled to be 10.25 μm.

[0125] The reaction solution was centrifuged, the obtained solid was washed with deionized water, dried at about 100°C and sieved through a 400 mesh screen to obtain a nickel-cobalt-manganese precursor Ni 0.87 Co 0.06 Mn 0.07 (OH)2.

[0126] The prepared nickel-cobalt-manganese precursor Ni 0.87 Co 0.06 Mn 0.07 (OH)2and lithium hydroxide were dry mixed according to a molar ratio of Li:(Ni 0.87 Co 0.06 Mn 0.07 )=1.05, and then the mixture was subjected to solid phase sintering reaction under a pure oxygen atmosphere, the solid phase sintering reaction temperature was 750°C, and the reaction time was 12 h to obtain a ternary positive electrode material, numbered as NCM-D5.

[0127] Test Example

[0128] The tap density (TD), specific surface area (SSA), FWHM 001 and FWHM 101 of the nickel-cobalt-manganese precursors prepared in Test Examples 1-8 and Comparative Examples 1-5 were tested, and the test results are shown in Table 1. The half peak width test graph of the nickel-cobalt-manganese precursor prepared in Example 1 is shown in Figure 1 , the half peak width test graph of the nickel-cobalt-manganese precursor prepared in Example 2 is shown in Figure 2 , the half peak width test graph of the nickel-cobalt-manganese precursor prepared in Example 3 is shown in Figure 3 , the half peak width test graph of the nickel-cobalt-manganese precursor prepared in Example 4 is shown in Figure 4 , and the half peak width test of the nickel-cobalt-manganese precursor prepared in Example 5 is shown in Figure 5The half peak width test graph of the nickel-cobalt-manganese precursor prepared by the preparation of Comparative Example 1 is shown in FIG. 1. Figure 6 The half peak width test graph of the nickel-cobalt-manganese precursor prepared by the preparation of Comparative Example 2 is shown in FIG. 2. Figure 7 The half peak width test graph of the nickel-cobalt-manganese precursor prepared by the preparation of Comparative Example 3 is shown in FIG. 3. Figure 8 The half peak width test graph of the nickel-cobalt-manganese precursor prepared by the preparation of Comparative Example 4 is shown in FIG. 4. Figure 9

[0129] The grain size and electrochemical performance of the ternary positive electrode material prepared by the preparation of Test Examples 1-8 and Comparative Examples 1-5 are tested according to the following method, and the test results are shown in Table 2.

[0130] Tap density (T.D.): The nickel-cobalt-manganese precursor in the container is tapped, and the mass per unit volume is measured.

[0131] Specific surface area (SSA): measured by low-temperature nitrogen adsorption method.

[0132] FWHM (001) , FWHM (101) : the half peak width of the (001), (101) crystal plane of the nickel-cobalt-manganese precursor (001), which can be directly read by jade software.

[0133] D 003 Grain size, D 104 Grain size: calculated by Scherrer formula, expression D (x) = Kλ / (βcosθ), D (x) is the grain size of the corresponding crystal plane of the positive electrode material; K is a constant, which is 0.89; λ is the X-ray wavelength; β is the half peak width of the diffraction peak of the corresponding crystal plane of the positive electrode material; θ is the diffraction angle corresponding to the diffraction peak of the corresponding crystal plane of the positive electrode material; when calculating D 003 , β is the half peak width of the (003) crystal plane diffraction peak of the positive electrode material, and θ is the diffraction angle corresponding to the (003) crystal plane diffraction peak of the positive electrode material; when calculating D 104 , β is the half peak width of the (104) crystal plane diffraction peak of the positive electrode material, and θ is the diffraction angle corresponding to the (104) crystal plane diffraction peak of the positive electrode material.

[0134] ​0.1C initial capacity, 1C 50 cycles retention rate at 45℃: ternary positive electrode material was mixed with acetylene black and PVDF at a mass ratio of 8:1:1 with N-methyl pyrrolidone as solvent, coated on aluminum foil, dried at 80℃ for 8h, and then vacuum dried at 120℃ for 12h; the battery was assembled in an argon glove box, with lithium metal as the negative electrode, polypropylene film as the separator, and 1M LiPF6-EC / DMC (1:1, v / v) as the electrolyte; the rate discharge was carried out at 0.1C under a specific cutoff voltage of 3-4.3V, the initial discharge capacity and initial efficiency were tested, and then the cycle capacity retention rate after 50 cycles was recorded at 1C under the same cutoff voltage as in the half-cell test.

[0135] Table 1

[0136]

[0137]

[0138] Table 2

[0139]

[0140] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but it should be considered that any combination of the technical features is within the scope of the present disclosure as long as the combination does not result in contradictions.

[0141] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present application should be subject to 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, where 0 < x < 1, 0 < y < 1, x + y < 1, and the FWHM of the nickel-cobalt-manganese precursor. (001) The range is 0.484-0.493, FWHM (101) The specific surface area of ​​the nickel-cobalt-manganese precursor is 6.22 m², which is 0.543-0.

552. 2 / g-8.36m 2 The tap density of the nickel-cobalt-manganese precursor is 1.95 g / cm³. 3 -2.00g / cm 3 .

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 sphere formed by primary particle agglomeration; (2) The D of the nickel-cobalt-manganese precursor 50 The particle size is 8μm-13μm.

3. A method for preparing a nickel-cobalt-manganese precursor as described in claim 1 or 2, characterized in that, Includes the following steps: Nickel salt, cobalt salt, and manganese salt are prepared into a metal salt solution in a certain proportion; and the metal salt solution, alkaline solution, and ammonia solution are mixed to carry out a co-precipitation reaction, when the product D 50 Once the particle size reaches the target size, the reaction is complete, yielding the nickel-cobalt-manganese precursor. During the co-precipitation reaction, the nitrogen flow rate is 195 L / min-240 L / min, the ammonia concentration is 6 g / L-9 g / L, the pH of the reaction solution is 10.35-10.95, and the temperature is 55℃-60℃. The co-precipitation reaction is carried out under stirring conditions, with a stirring speed of 400 rpm-500 rpm.

4. The method for preparing the nickel-cobalt-manganese precursor according to claim 3, characterized in that, During the coprecipitation reaction, air is simultaneously introduced at a flow rate of 30 L / min to 45 L / min.

5. The method for preparing the nickel-cobalt-manganese precursor according to claim 3, characterized in that, The molar ratio of nickel ions, cobalt ions and manganese ions in the metal salt solution is (85-90):(3-6):(4-12).

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

7. A nickel-cobalt-manganese ternary cathode material, characterized in that, The nickel-cobalt-manganese ternary cathode material is prepared by solid-state sintering of the nickel-cobalt-manganese precursor as described in claim 1 or 2, and the D of the nickel-cobalt-manganese ternary cathode material is... 003 The crystal grain size is 80nm-115nm, D 104 The crystal grain size is 40nm-55nm.

8. A method for preparing a nickel-cobalt-manganese ternary cathode material as described in claim 7, characterized in that, Includes the following steps: Provide the nickel-cobalt-manganese precursor as described in claim 1 or 2; as well as The nickel-cobalt-manganese precursor is mixed with lithium hydroxide in a certain proportion and then subjected to solid-state sintering to obtain a nickel-cobalt-manganese ternary cathode material. In the solid-state sintering step, the sintering temperature is less than or equal to 770°C.

9. The method for preparing the nickel-cobalt-manganese ternary cathode material according to claim 8, characterized in that, In the solid-state sintering step, the sintering time is 8h-14h.

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