Lithium-ion battery positive electrode material, precursor and preparation method therefor, lithium-ion battery and lithium battery device

Abstract

A lithium-ion battery positive electrode material, a precursor and a preparation method therefor, a lithium-ion battery and a lithium battery device, relating to the field of lithium-ion batteries. Secondary particles of the precursor comprise a plurality of strip-shaped or spindle-shaped primary particles, and a grain size ratio D(100) / D(001) of the precursor is 1.90-2.40. The preparation method comprises: adding raw materials including a metal salt solution, a precipitant and a complexing agent into a first base solution, and carrying out a first reaction according to a predetermined procedure until a crystal nucleus is obtained; and adding materials including the metal salt solution, the precipitant, the complexing agent and the crystal nucleus into a second base solution, and carrying out a second reaction according to a predetermined procedure. Raw materials of the lithium-ion battery positive electrode material comprise a precursor of the lithium-ion battery positive electrode material. According to the precursor, the growth of precursor materials on the face (001) is inhibited, so that the crystal face (100) becomes a dominant crystal face, the crystallinity is high, primary particles have good consistency, and the capacity performance and the cycle performance are both considered.

Description

Lithium-ion battery positive electrode material, precursor and preparation method thereof, lithium-ion battery and lithium battery equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to Chinese patent application number 202310799087.2, filed with the Patent Office of China on June 30, 2023, entitled “Lithium-ion battery positive electrode materials, precursors and preparation methods thereof, lithium-ion batteries and lithium-ion equipment,” the entire contents of which are incorporated by reference into this disclosure. Technical Field

[0003] The present disclosure relates to the field of lithium-ion batteries, and in particular to a lithium-ion battery positive electrode material, a precursor and a preparation method thereof, a lithium-ion battery and a lithium-ion battery device. Background Art

[0004] With the rapid development of the power battery market and the arrival of the first and second waves of large-scale battery replacement for new energy electric vehicles, end users, influenced by the high prices of power batteries, are increasingly concerned about the cycle life of power batteries. In addition, to reduce the number of charging times and charging time during travel, end users have been continuously putting forward new requirements for batteries with long battery life and high energy density.

[0005] As one of the four core materials of the battery, the positive electrode material restricts the overall performance of the battery, while the precursor material, as the raw material of the positive electrode material, determines the performance of the final material.

[0006] Due to their high nickel content, medium- and high-nickel precursors possess excellent properties such as high capacity and high battery energy density. Furthermore, nickel can replace cobalt, reducing costs and leading to increasing market demand. During the preparation process, the currently prepared medium- and high-nickel precursors exhibit differences in crystal structure due to the different growth advantages of the (001), (100), and (101) crystal planes, which affects electrochemical performance. Furthermore, the primary particles of medium- and high-nickel precursors have different morphologies, such as blocks, strips, spindles, and flakes. These primary particles, when arranged in different shapes, have different probabilities and degrees of rupture during pressure or charge and discharge, affecting cycling performance.

[0007] In their paper "Analysis and Improvement of Cyclic Attenuation of High-Nickel Ternary Lithium-Ion Batteries," Zhang Xin, Kong Lingli, Gao Tengyue, et al. conducted charge-discharge cycling tests on NCM811 / graphite cells at 45°C. During high-temperature cycling, the integrity of the cathode material's layered structure was significantly weakened, disrupting the crystal structure and hindering lithium ion migration, leading to cycling failure. Scanning electron microscopy (SEM) images revealed extensive, visible microcracks and even cracks in the cathode material's structure after extended cycling. The cathode material exhibited severe pulverization after extended high-temperature cycling. This is primarily due to the continuous expansion and contraction of the unit cell during repeated charge and discharge, which results in fracture and pulverization of the cathode material's particle structure, leading to material failure.

[0008] One of the most pressing challenges facing the industry is how to quickly identify products that achieve both high cycle performance and high capacity from a wide variety of medium- and high-nickel precursor materials using quantifiable parameters. Furthermore, how to prepare these identified products that achieve both high cycle performance and high capacity is also a pressing issue for the industry.

[0009] Summary of the Invention

[0010] The purpose of the present disclosure is to provide a lithium-ion battery positive electrode material, a precursor and a preparation method thereof, a lithium-ion battery and a lithium-ion battery device to solve the above problems.

[0011] To achieve the above objectives, the present disclosure adopts the following technical solutions:

[0012] A lithium-ion battery positive electrode material precursor, wherein the secondary particles of the precursor include a plurality of strip-shaped or spindle-shaped primary particles, and the precursor satisfies formula 1:

[0013] Formula 1: 1.50≤D (100) / D (001) ≤2.70,

[0014] In formula 1, D (100) is the grain size in the (100) crystal plane, D (001) is the grain size in the (001) crystal plane.

[0015] Specifically, the grain size can be calculated from the test data in the X-ray diffraction (XRD) pattern using the Scherrer formula.

[0016] Scherrer formula: D = kλ / [βcosθ],

[0017] in,

[0018] λ is the wavelength of X-rays;

[0019] β is the half-maximum width of the corresponding diffraction peak;

[0020] θ is the diffraction angle of the corresponding diffraction peak;

[0021] k is the Scherrer constant. Under the conditions set in the present disclosure (the secondary particles of the lithium-ion battery cathode material precursor are spherical, and β is the corresponding diffraction peak half-maximum width), k is 0.89. The same applies below.

[0022] Optionally, the lithium-ion battery cathode material precursor meets at least one of the following conditions:

[0023] (1) The precursor satisfies formula 2,

[0024] Formula 2: 1.50≤D (100) / D (001) ≤2.40;

[0025] Optionally, the precursor satisfies Formula 5,

[0026] Formula 5: 1.90≤D (100) / D (101) ≤2.40;

[0027] (2) The precursor satisfies formula 3,

[0028] Formula 3: 2.00≤D (100) / D (101) ≤2.90,

[0029] In formula 3, D (101) is the grain size in the (101) crystal plane, D (100) is the grain size in the (100) crystal plane;

[0030] Optionally, the precursor satisfies Formula 4,

[0031] Formula 4: 2.30≤D (100) / D (101) ≤2.70;

[0032] (3) The half maximum width (FWHM) of the precursor on the (101) crystal plane is 0.50°-0.65°;

[0033] (4) Diffraction peak intensity I of the precursor on the (101) crystal plane (101) The diffraction peak intensity of (001) crystal plane I (001) Ratio I (101) / I (001) 0.97-1.10;

[0034] (5) Number of wafers N of precursor on the (101) crystal plane (101) 50-80, N (101) =D (101) / d (101), d (101) represents the interplanar spacing of the (101) crystal plane;

[0035] Specifically, D (101) = kλ / [βcosθ (101) ,

[0036] d (101) == nλ / 2sinθ (101) = 0.23,

[0037] Then, N (101) = D (101) / d (101) = kλ / [0.23βcosθ (101) ,

[0038] where k is the Scherrer constant, and under the conditions set in this disclosure, k takes 0.89;

[0039] λ is

[0040] β is the FWHM (101) full width at half maximum;

[0041] Optionally, the number of wafers N of the precursor on the (101) crystal plane (101) is 60 - 70.

[0042] Optionally, the precursor of the lithium - ion battery cathode material satisfies at least one of the following conditions:

[0043] (1) The grain size of the precursor on the (001) crystal plane Optionally,

[0044] (2) The grain size of the precursor on the (101) crystal plane Optionally,

[0045] (3) The average grain size of the precursor Optionally, is

[0046] Optionally, the precursor of the lithium - ion battery cathode material satisfies at least one of the following conditions:

[0047] ① The average value of the absolute value of the relative deviation of the length of the primary particles |Ma| ≤ 40%, and the average value of the absolute value of the relative deviation of the width of the primary particles |Mb| ≤ 40%, where

[0048] a is the length of the primary particles, and b is the width of the primary particles,

[0049] is the average length of the primary particles, is the average width of the primary particles,

[0050] Specifically,

[0051] Among them,

[0052] a1, a2, a3, a n are the lengths of the 1st, 2nd, 3rd, and nth primary particles respectively, and b1, b2, b3, b n are the widths of the 1st, 2nd, 3rd, and nth primary particles respectively;

[0053] |Ma| and |Mb| are calculated by formula ① and formula ② respectively,

[0054] Formula ①:

[0055] Formula ②:

[0056] Specifically,

[0057] The average value of |Ma| = (|Ma1| + |Ma2| + |Ma3| +..... |Ma n |) / n,

[0058] The average value of |Mb| = (|Mb1| + |Mb2| + |Mb3| +..... |Mb n |) / n;

[0059] Among them,

[0060] |Ma1|, |Ma2|, |Ma3|, |Ma n | are the absolute values of the relative deviations of the lengths of the 1st, 2nd, 3rd, and nth primary particles respectively;

[0061] |Mb1|, |Mb2|, |Mb3|, |Mb n | are the absolute values of the relative deviations of the widths of the 1st, 2nd, 3rd, and nth primary particles respectively;

[0062] ② The precursor includes primary particles that satisfy ;

[0063] Optionally,

[0064] Optionally, the precursor of the positive electrode material of the lithium-ion battery satisfies at least one of the following conditions:

[0065] A. The chemical general formula of the precursor is Ni x M 1-x(OH)2, wherein 0≤x<1, and M is at least one of Co, Mn, Al, Ti, Zr, Mo, Cr, W, B, Mg, Ba, Nb or Sr;

[0066] Optionally, 0.6≤x<1;

[0067] B. The chemical formula of the precursor is Ni y Co z M 1 w M 2 v (OH)2, where 0≤y<1, 0≤z<0.6, y+z+w+v=1; M 1 is Mn and / or Al; M 2 At least one of Ti, Zr, Mo, Cr, W, B, Mg, Ba, Nb or Sr;

[0068] Optionally, 0.6≤y<1;

[0069] Optionally, 0≤w≤0.4; 0≤v≤0.1;

[0070] C. The particle size D50 of the secondary particles of the precursor is 8-22 μm;

[0071] D. The specific surface area of ​​the precursor is 8-20m 2 / g;

[0072] Optionally, the precursor has a BET surface area of ​​10-15 m 2 / g;

[0073] E. The tap density TD of the precursor is 1.8-2.1 g / cm 3 ;

[0074] F. The primary particles in the precursor are arranged in a disordered manner.

[0075] The present disclosure also provides a method for preparing a lithium-ion battery positive electrode material precursor, comprising:

[0076] Adding raw materials including a metal salt solution, a precipitant, and a complexing agent to a first base solution, and performing a first reaction according to a first predetermined procedure until a crystal nucleus is obtained;

[0077] preparing a second base liquid from materials including a metal salt solution, a precipitant, a complexing agent, and crystal nuclei, adding the metal salt solution, the precipitant, and the complexing agent to the second base liquid, and performing a second reaction according to a second predetermined procedure until a precursor is obtained;

[0078] Wherein, the first base liquid and the second base liquid independently include water, a precipitant and a complexing agent.

[0079] Optionally, the preparation method of the lithium-ion battery positive electrode material precursor meets at least one of the following conditions:

[0080] a. The first predetermined procedure includes: after the first reaction begins, gradually reducing the pH value during the first reaction, and maintaining the final pH value of the first reaction in the range of 9-11;

[0081] b. The second predetermined procedure includes: after the second reaction starts, adjusting the pH value of the second reaction so that the final pH of the second reaction is maintained within the range of 10-12.

[0082] Optionally, the preparation method of the lithium-ion battery positive electrode material precursor meets at least one of the following conditions:

[0083] c. The particle size D50 of the crystal nucleus is 3-10 μm;

[0084] d. The pH of the first base liquid and the second base liquid are each independently 10-12, and the ammonia concentration of the first base liquid and the second base liquid are each independently 1-15 g / L;

[0085] e. During the first reaction, the flow rate of the metal salt solution is 1-5% / h of the reaction vessel volume, the flow rate of the precipitant is 0.35-1.85% / h of the reaction vessel volume, and the flow rate of the complexing agent is 0.03-0.15% / h of the reaction vessel volume;

[0086] f. During the second reaction, the flow rate of the metal salt solution is 1-5% / h of the reaction vessel volume, the flow rate of the precipitant is 0.35-1.85% / h of the reaction vessel volume, and the flow rate of the complexing agent is 0.03-0.15% / h of the reaction vessel volume;

[0087] g. The temperature of the first reaction and the second reaction are each independently 60-80°C;

[0088] h. The mother liquor is continuously discharged during the first and second reactions, and the discharge amount is equal to the total feed amount;

[0089] i. After the second reaction is completed, post-processing is also included: the product of the second reaction is subjected to solid-liquid separation, drying, and screening for demagnetization.

[0090] The present disclosure also provides a lithium-ion battery positive electrode material, wherein the raw materials of the positive electrode material include a lithium-ion battery positive electrode material precursor.

[0091] The present disclosure also provides a lithium-ion battery, which includes a lithium-ion battery positive electrode material.

[0092] The present disclosure also provides a lithium battery device, including a lithium-ion battery.

[0093] Compared with the prior art, the advantages of the present invention include:

[0094] The primary particles in the lithium-ion battery positive electrode material precursor provided by the present disclosure are strip-shaped or spindle-shaped, which has better pressure-bearing capacity than thin sheets. The positive electrode material inheriting this structure is not easy to break when under pressure or when charging and discharging, which can improve the cycle performance of the battery. The present disclosure also defines the grain size D based on the characterization data calculated based on XRD (X-ray diffraction) data. (100) / D (001) ratio, because the (001) crystal plane of the precursor will be converted into the (003) crystal plane of the positive electrode active material after sintering, which is thermodynamically stable and electrochemically inert, which is not conducive to the transmission of lithium ions. + The transmission path and deintercalation speed of the precursor need to suppress the growth of the corresponding (001) crystal plane, make the (100) crystal plane the dominant crystal plane, suppress the grain size of the (001) crystal plane, and increase the grain size of the (100) crystal plane, thereby improving the battery capacity. (100) / D (001) The ratio range enables the battery prepared from the corresponding positive electrode material to take into account both cycle performance and capacity performance.

[0095] The present disclosure also provides a method for preparing a precursor for a positive electrode material for a lithium-ion battery. By controlling the pH values ​​of the first reaction and the second reaction, the primary particles in the resulting precursor are made to have a dominant (100) crystal plane, and the primary particle morphology is highly consistent, thereby giving the precursor excellent electrochemical performance. The present disclosure also improves the crystallinity and crystallization rate of the product by controlling the reaction temperature and reacting at a high temperature. The former improves the product crystallinity and improves the product's cycle performance, while the latter improves the crystallization rate and improves the product's production rate.

[0096] The lithium-ion battery positive electrode material, lithium-ion battery and lithium battery equipment provided by the present disclosure have good electrochemical stability and take both capacity and cycle performance into consideration. BRIEF DESCRIPTION OF THE DRAWINGS

[0097] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope of the present disclosure.

[0098] Figure 1 is a schematic diagram showing the comparison of primary particle consistency;

[0099] FIG2 is a partially enlarged SEM photograph of the surface of the secondary particles of the lithium-ion battery cathode material precursor obtained in Example 1;

[0100] FIG3 is an XRD pattern of the lithium-ion battery cathode material precursor obtained in Example 1;

[0101] FIG4 is a partially enlarged SEM photograph of the surface of the secondary particles of the lithium-ion battery cathode material precursor obtained in Example 2;

[0102] FIG5 is an XRD pattern of the lithium-ion battery cathode material precursor obtained in Example 2;

[0103] FIG6 is a partially enlarged SEM photograph of the surface of the secondary particles of the lithium-ion battery cathode material precursor obtained in Example 3;

[0104] FIG7 is an XRD pattern of the lithium-ion battery cathode material precursor obtained in Example 3;

[0105] FIG8 is a partially enlarged SEM photograph of the surface of the secondary particles of the lithium-ion battery cathode material precursor obtained in Example 5;

[0106] FIG9 is an XRD pattern of the lithium-ion battery cathode material precursor obtained in Example 5;

[0107] FIG10 is a partially enlarged SEM photograph of the surface of the secondary particles of the lithium-ion battery cathode material precursor obtained in Comparative Example 1;

[0108] FIG11 is an XRD pattern of the lithium-ion battery cathode material precursor obtained in Comparative Example 1;

[0109] FIG12 is a partially enlarged SEM photograph of the surface of the secondary particles of the lithium-ion battery positive electrode material precursor obtained in Comparative Example 2. DETAILED DESCRIPTION

[0110] As used herein:

[0111] As used herein, the term "comprise" or any other variation thereof is intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a listed element is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0112] When concentration, or other value or parameter is expressed as a range, an optional range, or a range limited by a series of upper and lower optional values, this should be understood to specifically disclose all ranges formed by any pairing of any range upper limit or optional value with any range lower limit or optional value, regardless of whether the range is disclosed alone. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including the range "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0113] A lithium-ion battery positive electrode material precursor, wherein the secondary particles of the precursor include a plurality of primary particles in the shape of strips or spindles, and the secondary particles of the precursor include a plurality of primary particles in the shape of strips or spindles, and the precursor satisfies formula 1,

[0114] Formula 1: 1.50≤D (100) / D (001) ≤2.70,

[0115] Specifically, the grain size can be calculated from the test data in the X-ray diffraction (XRD) pattern using the Scherrer formula.

[0116] Scherrer formula: D = kλ / [βcosθ],

[0117] in,

[0118] λ is the wavelength of X-rays;

[0119] β is the half-maximum width of the corresponding diffraction peak;

[0120] θ is the diffraction angle of the corresponding diffraction peak;

[0121] k is the Scherrer constant. Under the conditions set in the present disclosure (the secondary particles of the lithium-ion battery cathode material precursor are spherical, and β is the corresponding diffraction peak half-maximum width), k is 0.89. The same applies below.

[0122] Among them, the diffraction peak 2θ corresponding to the (001) crystal plane is 18.7°-19.7°, the diffraction peak 2θ corresponding to the (100) crystal plane is 32.7°-33.7°; the diffraction peak 2θ corresponding to the (101) crystal plane is 38.1°-39.1°.

[0123] For example, the crystal size D of lithium on the (001) crystal plane is calculated by XRD characterization data of the lithium-ion battery positive electrode material precursor in Example 1 of the present application. (001) When , in the above Scherrer formula:

[0124] ① Select K = 0.89;

[0125] ②The wavelength of the ray λ is

[0126] ③The diffraction angle 2θ of the diffraction peak corresponding to the (001) crystal plane is 19.226° (converted to radians);

[0127] ④ The half-maximum width β of the diffraction peak corresponding to the (001) crystal plane is 0.458°, which is converted into radians:

[0128] [(β÷180)×π]=[(0.458÷180)×π];

[0129] The calculation process is:

[0130] In formula 1, D (100) is the grain size in the (100) crystal plane, D (001) is the grain size in the (001) crystal plane. Alternatively, D (100) / D (001) The ratio can be 1.50, 1.60, 1.70, 1.80, 1.90, 1.95, 2.00, 2.05, 2.10, 2.15, 2.20, 2.25, 2.30, 2.35, or 2.40, or any value between 1.50-2.40, 1.50-1.90, 1.90-2.40, 1.90-2.10, 2.10-2.30, or 2.30-2.40.

[0131] Grain size ratio D (100) / D (001) It can be calculated by the following formula:

[0132] FWHM(001) is the half-maximum width of the (001) crystal plane corresponding to the precursor, and FWHM(100) is the half-maximum width of the (100) crystal plane corresponding to the precursor. More specifically, in X-ray diffraction (XRD) analysis, the half-maximum width (FWHM) refers to the peak width at half the height of the diffraction peak, that is, the distance between the two points where a straight line parallel to the peak bottom passes through the midpoint of the peak height and the intersection of this line with the two sides of the peak; FWHM(001) is the half-maximum width of the X-ray diffraction spectrum corresponding to the (001) crystal plane of the precursor, and FWHM(100) is the half-maximum width of the X-ray diffraction spectrum corresponding to the (100) crystal plane of the precursor.

[0133] For example, the crystal size D of lithium on the (001) crystal plane is calculated by XRD characterization data of the lithium-ion battery positive electrode material precursor in Example 1 of the present application. (100) / D (001) When , in the above Scherrer formula:

[0134] ① Select K = 0.89;

[0135] ②The wavelength of the ray λ is

[0136] ③ The diffraction angle 2θ of the diffraction peak corresponding to the (001) crystal plane is 19.226° (needs to be converted into radians), and the diffraction angle 2θ of the diffraction peak corresponding to the (100) crystal plane is 33.408° (needs to be converted into radians);

[0137] ④ The half-maximum width β of the diffraction peak corresponding to the (001) crystal plane (i.e., FWHM(001)) is 0.458°, and the half-maximum width β of the diffraction peak corresponding to the (100) crystal plane (i.e., FWHM(100)) is 0.226°. The formula for converting to radians is: [(β÷180)×π];

[0138] The calculation process is:

[0139] The precursor has (001) crystal plane, (100) crystal plane, (101) crystal plane, etc. + The transmission path and deintercalation speed of Li determine the performance of the material capacity. + To increase the mobility of other crystal planes, it is necessary to inhibit the growth of the corresponding precursor on the (001) crystal plane, thereby reducing the grain size on the (001) crystal plane and improving the capacity performance. (100) / D (001) , taking into account the cycle performance and capacity performance of the battery obtained after preparation.

[0140] Optionally, the lithium-ion battery cathode material precursor meets at least one of the following conditions:

[0141] (1) The precursor satisfies formula 2,

[0142] Formula 2: 2.10≤D (100) / D (001) ≤2.30;

[0143] (2) The precursor satisfies formula 3,

[0144] Formula 3: 2.00≤D (100) / D (101) ≤2.90,

[0145] In formula 3, D (101) is the grain size in the (101) crystal plane, D (100) is the grain size in the (100) crystal plane;

[0146] Optionally, the precursor satisfies Formula 4,

[0147] Formula 4: 2.30≤D (100) / D (101) ≤2.70;

[0148] Optionally, D (100) / D (101)The ratio can be 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80 or 2.90, or any value between 2.00-2.90, 2.00-2.50, 2.50-2.90, 1.90-2.40, 2.40-2.90, 2.70-2.90.

[0149] (3) The half maximum width (FWHM) of the precursor on the (101) crystal plane is 0.50°-0.65°;

[0150] Optionally, the half maximum width (FWHM) (101) of the precursor in the (101) crystal plane can be 0.50°, 0.51°, 0.52°, 0.53°, 0.54°, 0.55°, 0.56°, 0.57°, 0.58°, 0.59°, 0.60°, 0.61°, 0.62°, 0.63°, 0.64° or 0.65°, or any value between 0.50°-0.65°, 0.50°-0.57°, 0.57°-0.60°, and 0.60°-0.65°.

[0151] (4) Diffraction peak intensity I of the precursor on the (101) crystal plane (101) The intensity of the diffraction peak of (001) crystal plane is (001) Ratio I (101) / I (001) 0.97-1.10;

[0152] Among them, I (101) I is the peak intensity of the (101) crystal plane corresponding to the diffraction angle 2θ = 39.0 ± 1° in the precursor; (001) The peak intensity of the (001) crystal plane corresponding to the diffraction angle 2θ = 19.2 ± 1° exists in the precursor.

[0153] Optionally, the diffraction peak intensity I of the precursor at (101) crystal plane (101) The intensity of the diffraction peak of (001) crystal plane is (001) Ratio I (101) / I (001) can be 0.97, 0.98, 0.99, 1.00, 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, 1.10 or any value between 0.97-1.10, 0.97-0.99, 0.98-1.00, 0.99-1.10;

[0154] By further limiting the precursor D (100) / D (001) 、D (100) / D (101), FWHM(101), peak intensity ratio I (101) / I (001) , obtaining a specific crystal structure that can take into account both battery cycle and capacity performance.

[0155] (5) Number of wafers N of precursor on the (101) crystal plane (101) 50-80, N (101) =D (101) / d (101) , d (101) represents the interplanar spacing on the (101) crystal plane;

[0156] Specifically, D (101) =kλ / [βcosθ (101) ],

[0157] d (101) =nλ / 2sinθ (101) =0.23,

[0158] Then, by N (101) =D (101) / d (101) =kλ / [0.23βcosθ(101)]=kλ / [0.23FWHM(101)cosθ(101)],

[0159] Optionally, the number of wafers N of the precursor on the (101) crystal plane is (101) It is 60-70.

[0160] Wherein, k is the Scherrer constant. In the conditions set in this disclosure, k is set to 0.89;

[0161] λ is

[0162] β is the full width at half maximum (FWHM) (101).

[0163] Optionally, the number of wafers N of the precursor on the (101) crystal plane is (101) It can be 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80 or any positive integer between 50-80, 50-60, 60-70, 70-80.

[0164] For example, the number of lithium crystals N on the (101) crystal plane is calculated by XRD characterization data of the lithium-ion battery positive electrode material precursor in Example 1 of the present application. (001) When , in the above Scherrer formula:

[0165] ① Select K = 0.89;

[0166] ②The wavelength of the ray λ is

[0167] ③The diffraction angle 2θ of the diffraction peak corresponding to the (101) crystal plane is 38.616° (needs to be converted to radians);

[0168] ④ The half-maximum width β of the diffraction peak corresponding to the (101) crystal plane is 0.574°,

[0169] Converted to radians: [(β÷180)×π]=[(0.574÷180)×π];

[0170] The calculation process is:

[0171] Li + The transport path and deintercalation speed of the material determine the material's capacity. When the number of precursor material crystals on the (101) crystal plane is small, the transport path of the sintered cathode material on the converted crystal plane is short, which is conducive to the capacity. However, when the number of crystals on the (101) crystal plane is too small, the transport of lithium ions on the corresponding crystal plane of the inherited cathode material is affected, which is not conducive to the capacity.

[0172] The number of (101) crystal planes within a specific range ensures the insertion / deinsertion speed of lithium ions on the (101) crystal plane, taking into account the diffusion, transport, and insertion / deinsertion of lithium ions in the positive electrode material, thereby maximizing the capacity. The smaller the number of (101) crystal layers within a specific range, the higher the capacity; the larger the number of crystal layers, the better the cycling performance.

[0173] Optionally, the lithium-ion battery cathode material precursor meets at least one of the following conditions:

[0174] (1) Grain size of the precursor on the (001) crystal plane Optionally,

[0175] Optionally, the grain size D(001) of the precursor on the (001) crystal plane can be or Any value between

[0176] (2) Grain size of the precursor on the (101) crystal plane Optionally,

[0177] Optionally, the grain size D(001) of the precursor on the (100) crystal plane can be or Any value between

[0178] (3) Average grain size of the precursor is Optionally, is

[0179] Optionally, the grain size D(101) of the precursor on the (101) crystal plane can be or any value between;

[0180] The grain sizes of multiple crystal planes can reflect the overall situation of the crystal size. The grain sizes of multiple crystal planes are all relatively large, that is, the calculated average grain size is relatively large. From this, it can be inferred that the overall grain size is relatively large. The large average grain size of the product and high crystallinity are beneficial to the stability of the structure of the cathode material after sintering. When the battery is made, it is not easy to break after multiple contractions and expansions during charge and discharge, improving the cycle performance. However, too large grain size is not conducive to the transmission and insertion / extraction of Li + , affecting the capacity performance of the battery obtained after preparation.

[0181] Optionally, the precursor of the cathode material of the lithium-ion battery satisfies at least one of the following conditions:

[0182] ① The average value of the absolute value of the relative deviation |Ma| of the length of the primary particles ≤ 40%, and the average value of the absolute value of the relative deviation |Mb| of the width of the primary particles ≤ 40%.

[0183] Test method for the average value of the absolute value of the relative deviation |Ma| of the length of the primary particles and the average value of the absolute value of the relative deviation |Mb| of the width of the primary particles: Select complete primary particles in the local SEM image on the surface, screen out the primary particles that are not completely photographed at the edge of the image, randomly select 10 - 30 primary particles, measure the longest length a and the widest width b of each primary particle, and obtain the ranges of the length a and the width b respectively; then calculate the average length and the average width Finally, calculate the average value of the absolute value of the relative deviation |Ma| of the length and the average value of the absolute value of the relative deviation |Mb| of the width. To ensure consistent measurement rules, it should be ensured that the length direction and the width direction are perpendicular to each other, that is, first determine the longest length a of the primary particle, and then measure the widest width b in the direction perpendicular to the longest length direction, so as to obtain the data of the length a and the width b respectively.

[0184] Among them,

[0185] a is the length of the primary particle, b is the width of the primary particle,

[0186] is the average length of the primary particles, is the average width of the primary particles,

[0187] Specifically,

[0188] Among them,

[0189] a1, a2, a3, a n are respectively the lengths of the 1st, 2nd, 3rd, and nth selected primary particles, and b1, b2, b3, b n are respectively the widths of the 1st, 2nd, 3rd, and nth selected primary particles;

[0190] |Ma| and |Mb| are respectively calculated by formula ① and formula ②,

[0191] Formula ①:

[0192] Formula ②:

[0193] Specifically,

[0194] The average value of |Ma| = (|Ma1| + |Ma2| + |Ma3| +..... |Ma n |) / n,

[0195] The average value of |Mb| = (|Mb1| + |Mb2| + |Mb3| +..... |Mb n |) / n;

[0196] Among them,

[0197] |Ma1|, |Ma2|, |Ma3|, |Ma n | are respectively the absolute values of the relative deviations of the lengths of the 1st, 2nd, 3rd, and nth primary particles;

[0198] |Mb1|, |Mb2|, |Mb3|, |Mb n | are respectively the absolute values of the relative deviations of the widths of the 1st, 2nd, 3rd, and nth primary particles; <00​​​Optionally, the average value of the absolute value of the relative deviation of the length of the primary particles |Ma| and the average value of the absolute value of the relative deviation of the width |Mb| can each independently be 0, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40% or any value greater than or equal to 0 and less than or equal to 40%, 0 - 14%, 14 - 35%, 35 - 40%, 0 - 12%, 12 - 16%, 16 - 20%, 12 - 20%, 20 - 40%.

[0201] ② The precursor includes primary particles satisfying of the primary particles;

[0202] Optionally,

[0203] Optionally, 500nm ≤ a ≤ 1000nm, 50nm ≤ b ≤ 100nm,

[0204] where,

[0205] a is the length of the primary particles, b is the width of the primary particles,

[0206] is the average length of the primary particles, is the average width of the primary particles.

[0207] The relative deviation of the length and width of the primary particles are within a suitable range, which can ensure the uniform size of the primary particles, thereby obtaining a product with a suitable specific surface area and tap density, and appropriately taking into account the capacity and cycle performance of the battery. Optionally, the length and width of the primary particles need to be within a suitable range. Although in the same plane, abundant pores can be formed between the primary particles with a narrower width, which is conducive to the embedding and deintercalation of lithium ions, and the battery prepared by the positive electrode material has a higher capacity of the positive electrode material obtained after preparation, the primary particles with a narrower width are easy to break, resulting in poor cycle performance of the positive electrode material obtained after preparation; on the contrary, the primary particles with a wider width tend to be densely arranged, and the number of surface pores is reduced, which is not conducive to the embedding and deintercalation of lithium ions. The capacity of the positive electrode material obtained after preparation is lower, but the wider particles are not easy to break, and the cycle performance of the positive electrode material obtained after preparation is better; by limiting the width range of the primary particles, the capacity and cycle performance of the battery can be appropriately taken into account. As shown in Figure 1, Class A primary particles are coarse and uniform in size, Class B primary particles are uneven, and Class C primary particles are fine and uniform in size. Considering that the uneven size of primary particles will affect battery performance, the battery performance prepared with Class B primary particles is worse than that of Class A and Class C primary particles.

[0208] Optionally, the precursor includes a mean length 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm, 1100nm, 1200nm or any value between 300-1200nm, 300-500nm, 500-800nm, 600-800nm, 800-1000nm, 1000-1200nm, the average width of the primary particles The primary particles have a size of 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm or any value between 50-200 nm, 50-90 nm, 60-100 nm, 80-100 nm, 50-80 nm, 90-200 nm, and 100-200 nm.

[0209] In an optional embodiment, the lithium-ion battery positive electrode material satisfies at least one of the following conditions:

[0210] A. The chemical formula of the precursor is Ni x M 1-x (OH)2, wherein 0≤x<1, and M is at least one of Co, Mn, Al, Ti, Zr, Mo, Cr, W, B, Mg, Ba, Nb or Sr;

[0211] Optionally, 0.6≤x<1;

[0212] Optionally, x can be any value of 0, 0.01, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 0.99, or greater than or equal to 0, less than 1, 0≤x<0.6, 0.6≤x<1, 0.6≤x<0.8, 0.8≤x<1, 0.8≤x<0.9, 0.9≤x<1, and 0.95≤x<1.

[0213] B. The chemical formula of the precursor is Ni y Co z M 1 w M 2 v (OH)2, where 0≤y<1, 0≤z<0.6, y+z+w+v=1; M 1 is Mn and / or Al; M 2 At least one of Ti, Zr, Mo, Cr, W, B, Mg, Ba, Nb or Sr;

[0214] Optionally, 0.6≤y<1;

[0215] Optionally, 0≤w≤0.4; 0≤v≤0.1;

[0216] Optionally, y can be 0, 0.01, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 0.99 or greater than or equal to 0, less than 1, 0≤y<0.6, 0.6≤y<1, 0.6≤y<0.8, 0. 8≤y<1, 0.8≤y<0.9, 0.9≤y<1, 0.95≤y<1; z can be 0, 0.01, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.59 or greater than or equal to 0, less than 0.6, 0≤z<0.1, 0.1≤z<0.2, 0.2≤z<0.3, 0 .3≤z<0.4, 0.4≤z<0.5, 0.5≤z<0.6; w can be 0, 0.01, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40 or any value greater than or equal to 0, less than 0.4, 0≤w<0.1, 0.1≤w<0.2, 0.2≤w<0.3, 0.3≤w<0.4; v can be 0, 0.01, 0. 0.2, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10 or any value greater than or equal to 0, less than 0.1, 0≤v<0.01, 0.01≤v<0.02, 0.02≤v<0.03, 0.03≤v<0.04, 0.02≤v<0.04, 0.04≤v<0.06, 0.06≤v<0.08, 0.08≤v<0.1.

[0217] The lithium-ion battery positive electrode material precursor provided by the present disclosure can be a binary precursor material or a ternary precursor material.

[0218] C. The particle size D50 of the secondary particles of the precursor is 8-22 μm;

[0219] D. The specific surface area of ​​the precursor is 8-20m 2 / g;

[0220] Optionally, the precursor has a BET surface area of ​​10-15 m 2 / g;

[0221] E. The tap density TD of the precursor is 1.8-2.1 g / cm 3 .

[0222] Optionally, the particle size D50 of the secondary particles of the precursor can be 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm or any value between 8-22 μm, 8-12 μm, 12-16 μm, 16-22 μm, and 10-18 μm; the specific surface area BET of the precursor can be 8 m 2 / g、9m 2 / g、10m 2 / g、11m 2 / g、12m 2 / g、13m 2 / g、14m 2 / g、15m 2 / g、16m 2 / g、17m 2 / g、18m 2 / g、19m 2 / g, 20m 2 / g or 8-20m 2 / g, 8-13m 2 / g, 13-20m 2 / g, 10-16m 2 / g; the tap density TD of the precursor can be 1.8g / cm 3 , 1.85g / cm 3 , 1.9g / cm 3 , 1.95g / cm 3 , 2.0g / cm 3 , 2.05g / cm 3 , 2.1g / cm 3 or 1.8-2.1g / cm 3 , 1.8-1.9g / cm 3 , 1.9-2.0g / cm 3 , 2.0-2.1g / cm 3 Any value in between.

[0223] Under the same conditions, particle size is positively correlated with tap density: the larger the particle size, the greater the tap density. Tap density can increase the compaction density of the cathode material that inherits the precursor, thereby increasing energy density and, consequently, battery capacity.

[0224] Specific surface area is measured using nitrogen adsorption. A larger specific surface area indicates more pores in the precursor. Rich pores increase the contact area between the cathode material and the electrolyte after sintering, accelerating the electrochemical reaction rate and improving battery capacity. However, an excessively high specific surface area may result in excessive pores in the material, leading to rupture under pressure or due to stress changes during charge and discharge, thus affecting cycling performance.

[0225] In summary, by limiting the particle size, tap density, and specific surface area, the capacity and cycle of the battery can be taken into account.

[0226] F. The primary particles in the precursor are arranged in a disordered manner;

[0227] The primary particles of the secondary particle spheres are arranged in a disordered manner, which can increase the distance between the primary particles while keeping the length and width of the primary particles unchanged, and increase the number of pores on the surface of the secondary particle spheres, thereby facilitating the embedding and de-embedding of lithium salts and improving battery capacity.

[0228] The present disclosure also provides a method for preparing a lithium-ion battery positive electrode material precursor, comprising:

[0229] Adding raw materials including a metal salt solution, a precipitant, and a complexing agent to a first base solution, and performing a first reaction according to a first predetermined procedure until a crystal nucleus is obtained;

[0230] preparing a second base liquid from materials including a metal salt solution, a precipitant, a complexing agent, and crystal nuclei, adding the metal salt solution, the precipitant, and the complexing agent to the second base liquid, and performing a second reaction according to a second predetermined procedure until a precursor is obtained;

[0231] Wherein, the first base liquid and the second base liquid each independently include water, a precipitant and a complexing agent.

[0232] In an optional embodiment, the preparation method of the lithium-ion battery positive electrode material precursor meets at least one of the following conditions:

[0233] a. The first predetermined procedure includes: after the first reaction begins, gradually reducing the pH value during the first reaction, and maintaining the final pH value of the first reaction in the range of 9-11;

[0234] Optionally, the final pH of the first reaction is maintained at 9, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10, 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, 11 or any value in the range of 9-11, 9-10, 9.5-10.5, 10-11, 9.0-9.5, 10.5-11.0;

[0235] b. The second predetermined procedure includes: after the second reaction starts, adjusting the pH value of the second reaction so that the final pH of the second reaction is maintained within the range of 10-12.

[0236] Optionally, the final pH of the second reaction is maintained at 10, 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, 11, 11.1, 11.2, 11.3, 11.4, 11.5, 11.6, 11.7, 11.8, 11.9, 12 or any value in the range of 10-12, 10-11, 11-12, 10-10.5, 10.5-11.5, 11.5-12.

[0237] Optionally, the preparation method of the lithium-ion battery positive electrode material precursor meets at least one of the following conditions:

[0238] c. The particle size D50 of the crystal nucleus is 3-10 μm;

[0239] Optionally, the particle size D50 of the crystal nucleus may be 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, or any value between 3-10 μm, 3-6 μm, 6-8 μm, 8-10 μm, and 4-7 μm;

[0240] d. The pH of the first base liquid and the second base liquid are each independently 10-12, and the ammonia concentration of the first base liquid and the second base liquid are each independently 1-15 g / L;

[0241] Optionally, the pH of the first base solution and the second base solution can be 10, 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, 11, 11.1, 11.2, 11.3, 11.4, 11.5, 11.6, 11.7, 11.8, 11.9, 12 or 10-12, 10-11, 11-12, 10-10.5, 10.5-11.5, 1 The ammonia concentration of the first base liquid and the second base liquid can be any value between 1.5 and 12, and the ammonia concentration of each of the first base liquid and the second base liquid can be independently 1 g / L, 2 g / L, 3 g / L, 4 g / L, 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L, 10 g / L, 11 g / L, 12 g / L, 13 g / L, 14 g / L, 15 g / L or any value between 1-15 g / L, 1-5 g / L, 5-10 g / L, 10-15 g / L, 3-8 g / L, and 8-12 g / L;

[0242] e. During the first reaction, the flow rate of the metal salt solution is 1-5% / h of the reaction vessel volume, the flow rate of the precipitant is 0.35-1.85% / h of the reaction vessel volume, and the flow rate of the complexing agent is 0.03-0.15% / h of the reaction vessel volume;

[0243] Optionally, during the first reaction, the flow rate of the metal salt solution can be 1% / h, 1.1% / h, 1.2% / h, 1.3% / h, 1.4% / h, 1.5% / h, 1.6% / h, 1.7% / h, 1.8% / h, 1.9% / h, 2% / h, 2.1% / h, 2.2% / h, 2.3% / h, 2.4% / h, 2.5% / h, 2.6% / h, 2.7% / h, 2.8% / h, 2.9% / h, 3% / h, 3.0% / h, 3.1% / h, 3.2% / h, 3.3% / h, 3.4% / h, 3.5% / h, 3.6% / h, 3.7% / h, 3.8% / h, 3.9% / h, 4.0% / h, 4.1% / h, 4.2% / h, 4.3% / h, 4.4% / h, 4.5% / h, 4.6% / h, 4.7% / h, 4.8% / h, 4.9% / h, 5.0% / h, 5.1% / h, 5.2% / h, 5.3% / h, 5.4% / h, 5.5% / h, 5.6% / h, 5.7% / h, 5.8% / h, 5.9% / h, 6. The flow rate of the precipitant may be 0.35%, 0.40%, 0.45%, 0.50%, 0.55%, 0.60%, 0.65%, 0.70%, 0.80%, 0.90%, 0.95%, 0.96%, 0.97%, 0.98%, 0.99%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, 0.40%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.5 0% / h, 0.75% / h, 0.80% / h, 0.85% / h, 0.90% / h, 0.95% / h, 1.00% / h, 1.10% / h, 1.15% / h, 1.20% / h, 1.25% / h, 1.30% / h, 1.35% / h, 1.40% / h , 1.45% / h, 1.50% / h, 1.55% / h, 1.60% / h, 1.65% / h, 1.70% / h, 1.75% / h, 1.80% / h, 1.85% / h or 0.35-1.85% / h, 0.35-0.70% / h, 0.70-1.1 0% / h, 1.10-1.85% / h, the flow rate of the complexing agent can be 0.03% / h, 0.04% / h, 0.05% / h, 0.06% / h, 0.07% / h, 0.08% / h, 0.09% / h, 0.10% / h, 0.11% / h, 0.12% / h, 0.13% / h, 0.14% / h, 0.15% / h or any value between 0.03-0.15% / h, 0.03-0.06% / h, 0.06-0.08% / h, 0.08-0.10% / h, 0.10-0.15% / h of the reaction vessel volume;

[0244] f. During the second reaction, the flow rate of the metal salt solution is 1-5% / h of the reaction vessel volume, the flow rate of the precipitant is 0.35-1.85% / h of the reaction vessel volume, and the flow rate of the complexing agent is 0.03-0.15% / h of the reaction vessel volume;

[0245] Optionally, during the second reaction, the flow rate of the metal salt solution can be 1% / h, 1.1% / h, 1.2% / h, 1.3% / h, 1.4% / h, 1.5% / h, 1.6% / h, 1.7% / h, 1.8% / h, 1.9% / h, 2% / h, 2.1% / h, 2.2% / h, 2.3% / h, 2.4% / h, 2.5% / h, 2.6% / h, 2.7% / h, 2.8% / h, 2.9% / h, 3% / h, 3.0% / h, 3.1% / h, 3.2% / h, 3.3% / h, 3.4% / h, 3.5% / h, 3.6% / h, 3.7% / h, 3.8% / h, 3.9% / h, 4.0% / h, 4.1% / h, 4.2% / h, 4.3% / h, 4.4% / h, 4.5% / h, 4.6% / h, 4.7% / h, 4.8% / h, 4.9% / h, 5.0% / h, 5.1% / h, 5.2% / h, 5.3% / h, 5.4% / h, 5.5% / h, 5.6% / h, 5.7% / h, 5.8% / h, 5.9% / h The flow rate of the precipitant may be 0.35%, 0.40%, 0.45%, 0.50%, 0.55%, 0.60%, 0.65%, 0.70%, 0.80%, 0.90%, 0.95%, 0.96%, 0.97%, 0.98%, 0.99%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, 0.40%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.5 0% / h, 0.75% / h, 0.80% / h, 0.85% / h, 0.90% / h, 0.95% / h, 1.00% / h, 1.10% / h, 1.15% / h, 1.20% / h, 1.25% / h, 1.30% / h, 1.35% / h, 1.40% / h , 1.45% / h, 1.50% / h, 1.55% / h, 1.60% / h, 1.65% / h, 1.70% / h, 1.75% / h, 1.80% / h, 1.85% / h or 0.35-1.85% / h, 0.35-0.70% / h, 0.70-1.1 0% / h, 1.10-1.85% / h, the flow rate of the complexing agent can be 0.03% / h, 0.04% / h, 0.05% / h, 0.06% / h, 0.07% / h, 0.08% / h, 0.09% / h, 0.10% / h, 0.11% / h, 0.12% / h, 0.13% / h, 0.14% / h, 0.15% / h or any value between 0.03-0.15% / h, 0.03-0.06% / h, 0.06-0.08% / h, 0.08-0.10% / h, 0.10-0.15% / h of the reaction vessel volume;

[0246] g. The temperature of the first reaction and the second reaction are each independently 60-80°C;

[0247] Optionally, the temperature of the first reaction and the second reaction can be independently 60°C, 65°C, 70°C, 75°C, 80°C, or any value between 60-80°C, 60-70°C, 70-80°C, and 65-75°C;

[0248] h. The mother liquor is continuously discharged during the first and second reactions, and the discharge amount is equal to the total feed amount;

[0249] i. After the second reaction is completed, post-processing is also included: the product of the second reaction is subjected to solid-liquid separation, drying, and screening for demagnetization.

[0250] The present disclosure also provides a lithium-ion battery positive electrode material, wherein the raw materials of the positive electrode material include a lithium-ion battery positive electrode material precursor.

[0251] The present disclosure also provides a lithium-ion battery, which includes a lithium-ion battery positive electrode material.

[0252] The present disclosure also provides a lithium battery device, including a lithium-ion battery.

[0253] The embodiments of the present disclosure will be described in detail below with reference to specific examples. However, those skilled in the art will appreciate that the following examples are intended only to illustrate the present disclosure and should not be construed as limiting the scope of the present disclosure. Where specific conditions are not specified in the examples, conventional conditions or conditions recommended by the manufacturer were used. Reagents or instruments used where the manufacturer is not specified are conventional products that can be purchased commercially.

[0254] Example 1

[0255] This embodiment provides a lithium-ion battery positive electrode material precursor, and the preparation method thereof is as follows:

[0256] Step 1: Calculate and weigh nickel sulfate crystals, cobalt sulfate crystals, and manganese sulfate crystals, and prepare a metal salt solution with a total metal molar weight of 2 mol / L according to the metal molar ratio of nickel, cobalt, and manganese of Ni:Mn:Co=88.5:8:3.5;

[0257] Step 2: Add pure water, sodium hydroxide solution and ammonia water to the reactor and stir evenly at 220 r / min. Keep the temperature at 60°C to obtain a first bottom solution with a pH value of 11.5 and an ammonia concentration of 4.5 g / L.

[0258] Step 3: Under stirring at 220 r / min, metal salt solution, sodium hydroxide solution, and ammonia water are simultaneously introduced into the reactor having been added to the bottom liquid at flow rates of 2.0-2.1% / h, 0.7-1.0% / h, and 0.06-0.08% / h of the reactor volume, respectively. The temperature is kept constant at 60°C. After the reaction precipitation begins, the pH is gradually reduced by adjusting the flow rate of liquid alkali and finally maintained within the range of 10.8-11.0. During the reaction, the mother liquor is discharged through a concentration device at a rate consistent with the total feed rate until nickel-cobalt-manganese precipitation nuclei with a medium particle size D50 of 5.1 μm are obtained and dehydrated.

[0259] Step 4: Under stirring at 220 r / min, the dehydrated nickel-cobalt-manganese crystal nuclei obtained in step 3 are placed in a reactor, and water, sodium hydroxide solution, and aqueous ammonia are added to obtain a second bottom solution with a pH of 10.8 and an ammonia concentration of 3.7 g / L. The metal salt solution, sodium hydroxide solution, and aqueous ammonia are continuously introduced into the reactor at flow rates of 2.0-2.1% / h, 0.7-1.0% / h, and 0.06-0.08% / h of the reactor volume, respectively. The temperature is maintained at 75°C. After the reaction precipitation begins, the pH is gradually reduced to 10.6 by adjusting the liquid caustic soda flow rate, and then the pH is gradually increased and finally maintained at a value of 11.1-11.3. During the reaction, the mother liquor is discharged through a concentration device at a rate consistent with the total feed amount until a nickel-cobalt precipitate with a D50 of 11.0 μm is obtained.

[0260] Step 5: Wash, centrifuge, dry, and sieve the reaction precipitate slurry to remove magnetism, and obtain a precursor of the positive electrode material for lithium-ion batteries having the chemical formula of Ni 0.885 Co 0.08 Mn 0.035 (OH)2.

[0261] The SEM partial magnified photograph of the surface of the secondary particles of the obtained lithium-ion battery positive electrode material precursor is shown in FIG2 , and the XRD pattern is shown in FIG3 .

[0262] In Figure 2, select the primary particles with good integrity, filter out the primary particles that are not fully photographed at the edge of the picture, measure the longest length a and widest width b of each primary particle, and obtain the range of length a and width b respectively; then calculate the average length and average width Finally, the average value of the absolute value of the relative deviation of length |Ma| and the average value of the absolute value of the relative deviation of width |Mb| are calculated. The test method is the same below.

[0263] Example 2

[0264] Compared with Example 1, this embodiment is different in that:

[0265] Step 1: Calculate and weigh nickel sulfate crystals and manganese sulfate crystals, and prepare a metal salt solution with a total metal molar weight of 2 mol / L according to the metal molar ratio of nickel to manganese (Ni:Mn=88.5:11.5);

[0266] In step 4: After the reaction begins, the pH is gradually lowered to 10.5 by adjusting the flow rate of the sodium hydroxide solution. The pH is then gradually raised and maintained at 10.6-10.8. The magnitude of the pH drop and the pH maintained ultimately result in differences in the width and length of the resulting primary particles.

[0267] The chemical formula of the precursor of the positive electrode material of lithium-ion battery is Ni 0.885 Mn 0.115 (OH)2.

[0268] A local magnified photograph of the surface of the secondary particles of the obtained lithium-ion battery cathode material precursor is shown in FIG4 , and the XRD pattern is shown in FIG5 .

[0269] Example 3

[0270] Compared with Example 1, this embodiment is different in that:

[0271] Step 1: Calculate and weigh nickel sulfate crystals, cobalt sulfate crystals, manganese sulfate crystals, and aluminum sulfate crystals, and prepare a metal salt solution with a total metal molar weight of 2 mol / L according to the metal molar ratio of nickel, cobalt, manganese, and aluminum (Ni:Co:Mn:Al=88:3:7:2);

[0272] In step 4, the dehydrated nickel-cobalt-manganese-aluminum nuclei with a D50 of 5 μm obtained in step 3 are placed in a reactor, and water, sodium hydroxide solution, and aqueous ammonia are added to obtain a second base solution with a pH of 10.6 and an ammonia concentration of 10.0 g / L. The metal salt solution, sodium hydroxide solution, and aqueous ammonia are then simultaneously introduced into the reactor at flow rates of 1.0-1.1% / h, 0.35-0.55% / h, and 0.03-0.05% / h of the reactor volume, respectively. The temperature is maintained at 65°C. After the reaction begins, the pH is gradually increased to 11.0 by adjusting the flow rate of the sodium hydroxide solution, and then gradually decreased and ultimately maintained at 10.1-10.3. The difference in the pH drop and the final pH value maintained results in differences in the width and length of the resulting primary particles.

[0273] The chemical formula of the precursor of the positive electrode material of lithium-ion battery is Ni 0.88 Co 0.03 Mn 0.07 Al 0.02 (OH)2.

[0274] The SEM partial magnified photograph of the surface of the secondary particles of the obtained lithium-ion battery positive electrode material precursor is shown in FIG6 , and the XRD pattern is shown in FIG7 .

[0275] Example 4

[0276] Compared with Example 1, this embodiment is different in that:

[0277] Step 1: Calculate and weigh nickel sulfate crystals and manganese sulfate crystals, and prepare a metal salt solution with a total metal molar weight of 2 mol / L according to the metal molar ratio of nickel to manganese (Ni:Mn=80:20);

[0278] In step 4: under stirring at 300 r / min, the dehydrated nickel-manganese crystal nuclei with a D50 of 5 μm obtained in step 3 are placed in a reactor, and water, sodium hydroxide solution, and ammonia water are added to obtain a second bottom solution with a pH value of 10.3 and an ammonia concentration of 9.8 g / L. The metal salt solution, sodium hydroxide solution, and ammonia water are continuously introduced into the reactor at flow rates of 1.0-1.1% / h, 0.32-0.52% / h, and 0.03-0.05% / h of the reactor volume, respectively. The temperature is maintained at 65°C. After the reaction begins, the pH is gradually increased to 10.8 by adjusting the flow rate of sodium hydroxide solution, and then the pH is gradually decreased and finally maintained at 10.0-10.2. The different pH drop and the final maintained pH value, as well as the increased stirring speed, result in differences in the width and length of the final primary particles.

[0279] The chemical formula of the lithium ion battery cathode material precursor obtained in the present disclosure is Ni 0.80 Mn 0.20 (OH)2.

[0280] Example 5

[0281] This comparative example differs from Example 1 in that, after the reaction begins, in step 4, the flow rate of the sodium hydroxide solution is adjusted to gradually decrease the pH to 10.5, then gradually increase the pH and ultimately maintain it at 11.1-11.3. The difference in the pH decrease and the pH maintained ultimately results in differences in the width and length of the resulting primary particles.

[0282] The chemical formula of the obtained material is Ni 0.885 Co 0.08 Mn 0.035 (OH)2.

[0283] The SEM partial magnified photograph of the surface of the secondary particles of the obtained lithium-ion battery positive electrode material precursor is shown in FIG8 , and the XRD pattern is shown in FIG9 .

[0284] Comparative Example 1

[0285] This comparative example differs from Example 1 in that, in step 4, after the reaction begins, the flow rate of the sodium hydroxide solution is adjusted to gradually increase the pH and ultimately maintain it at a value of 11.4-11.6. The magnitude of the pH decrease and the pH value ultimately maintained result in differences in the width and length of the resulting primary particles.

[0286] The SEM partial magnified photograph of the surface of the secondary particles of the obtained lithium-ion battery positive electrode material precursor is shown in FIG10 , and the XRD pattern is shown in FIG11 .

[0287] The present invention discloses the composite structure of Ni 0.885 Co 0.08 Mn 0.035 (OH)2 material.

[0288] Comparative Example 2

[0289] Compared with Example 1, the difference between this comparative example and Example 1 is that in step 3: the metal salt solution, sodium hydroxide solution and ammonia water are simultaneously introduced into the reactor having been added to the bottom liquid at a flow rate of 2.0-2.1% / h, 0.7-1.0% / h and 0.06-0.08% / h of the volume of the reactor, respectively, and the temperature is kept at 50°C. After the reaction precipitation begins, the pH is gradually reduced by adjusting the flow rate of liquid alkali and finally maintained in the range of 10.8-11.0. During the reaction, the mother liquor is discharged through the concentration equipment, and the discharge rate is consistent with the total feed amount; until a nickel-cobalt-manganese precipitate nucleus with a medium particle size D50 of 5.1 μm is obtained and dehydrated. The difference in reaction temperature leads to differences in the width and length of the primary particles finally obtained.

[0290] The present invention discloses the composite structure of Ni 0.885 Co 0.08 Mn 0.035 (OH)2 material, the SEM partial magnified photograph of the surface of the secondary particles of the obtained lithium-ion battery positive electrode material precursor is shown in Figure 12.

[0291] The test data of the precursor materials obtained in each embodiment and comparative example are shown in Tables 1, 2, 3 and 4 below:

[0292] Table 1 XRD data of precursor materials obtained in each embodiment and comparative example

[0293] Table 2 XRD data of precursor materials obtained in each embodiment and comparative example

[0294] Table 3 Primary particle data of precursor materials obtained in each embodiment and comparative example

[0295] Table 4 Other test data of precursor materials obtained in each embodiment and comparative example

[0296] Cathode material preparation:

[0297] The precursors prepared in each embodiment and comparative example and LiOH were mixed uniformly in a molar ratio of 1:1.05 by a high-speed mixer, sintered at 850°C for 6 hours in an air atmosphere in a box furnace, and then cooled to room temperature and pulverized and sieved to obtain a ternary positive electrode material.

[0298] Battery preparation:

[0299] Electrochemical performance testing was conducted using a coin-type semi-battery: The aforementioned positive electrode materials, conductive carbon black, and binder PVDF (polyvinylidene fluoride) were mixed into a slurry in appropriate proportions and coated onto aluminum foil to form the positive electrode sheet. A metallic lithium sheet was used as the negative electrode, and the electrolyte used was 1 mol / L LiPF6 / EC:DMC (volume ratio 1:1). 1C = 200 mAh / g. In a vacuum glove box, the battery case, positive and negative electrode sheets, separator, spring, and gasket were assembled into a button cell. Electrochemical performance testing was conducted using a Blue Electric test system.

[0300] The electrochemical data of the batteries obtained in each embodiment and comparative example are shown in Table 5:

[0301] Table 5 Electrochemical data of the batteries obtained in each embodiment and comparative example

[0302] Note: 0.5C high temperature cycle efficiency (50th) (%) refers to the battery capacity retention rate after 50 cycles of charge and discharge test at 0.5C at 45℃.

[0303] By comparing the above embodiments and comparative examples, the following conclusions can be drawn:

[0304] The products of different molecular formulas obtained in Examples 1, 2, 3, 4, and 5 are all long strips or spindle-shaped primary particles, and the XRD parameters are within the protection range, making the (100) crystal plane and (101) crystal plane of the precursor material the dominant crystal planes, with high crystallinity, good primary particle consistency, and taking into account both capacity and cycle performance.

[0305] Compared with Example 1, although the specific surface area BET of Example 5 is larger, it is beneficial for electrolyte penetration and improves capacity performance, but (100) / D (001) The ratio is too low, the number of crystals on the (101) crystal plane is too large, exceeding the limit range, and the battery capacity is low under the combined influence. In addition, the length of the primary particles is too short, the width is too thin, and the morphology does not meet the requirements; FWHM (101) and D (100) / D (101)A small ratio may affect the crystal structure. During charging and discharging, the unit cell continuously expands and contracts, causing the positive electrode material particle structure to break and pulverize, ultimately showing poor cycle performance.

[0306] Compared with Example 1, although Comparative Example 1 meets the requirements of the number of wafers and D (100) / D (001) The numerical range requirements are met, but the primary particle morphology is blocky and the consistency is poor, showing a small BET specific surface area and a high tap density, which ultimately manifests as poor capacity and insignificant cycle differences.

[0307] Compared with Example 1, the primary particle morphology of Comparative Example 2 is shorter in length and thinner in width, and the D(100) / D(001) values ​​do not meet the requirements, showing that the BET specific surface area is too large and the tap density is too low, which ultimately manifests as poor and significant cycle differences.

[0308] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present disclosure.

[0309] Furthermore, those skilled in the art will appreciate that although some embodiments herein include certain features included in other embodiments but not other features, the combination of features from different embodiments is intended to be within the scope of this disclosure and to form different embodiments. For example, in the claims above, any of the claimed embodiments may be used in any combination. The information disclosed in this background section is intended solely to enhance understanding of the overall background of this disclosure and should not be construed as an admission or any form of implication that such information constitutes prior art already known to those skilled in the art. Industrial Applicability

[0310] In summary, the primary particles in the lithium-ion battery positive electrode material precursor provided by the present disclosure are strip-shaped or spindle-shaped, which has better pressure-bearing capacity than thin sheets. The positive electrode material inheriting this structure is not easy to break when under pressure or when charging and discharging, which can improve the battery cycle performance. The present disclosure also defines the grain size D based on the characterization data calculated based on XRD data. (100) / D (001) The present invention limits the primary particle morphology and grain size D of the precursor. (100) / D (001) , so that the battery prepared with the corresponding positive electrode material takes into account both cycle performance and capacity performance.

[0311] Furthermore, it is understood that the lithium-ion battery cathode material, precursor, and preparation method thereof, lithium-ion battery, and lithium-ion battery device of the present application are reproducible and can be used in a variety of industrial applications. For example, the lithium-ion battery cathode material and its precursor of the present application can be used in the field of lithium-ion batteries.

Claims

1. A lithium-ion battery positive electrode material precursor, characterized in that: The secondary particles of the precursor include a plurality of primary particles in the shape of strips or shuttles, and the precursor satisfies Formula 1: Formula 1: 1.50≤D (100) / D (001) ≤2.70, In formula 1, D (100) is the grain size in the (100) crystal plane, D (001) is the grain size in the (001) crystal plane.

2. The lithium-ion battery positive electrode material precursor according to claim 1, characterized in that: Meet at least one of the following conditions: (1) The precursor satisfies Formula 2, Formula 2: 1.50≤D (100) / D (001) ≤2.40; (2) The precursor satisfies Formula 3, Formula 3: 2.00≤D (100) / D (101) ≤2.90, In formula 3, D (101) is the grain size in the (101) crystal plane, D (100) is the grain size in the (100) crystal plane; (3) The full width at half maximum FWHM(101) of the (101) crystal plane of the precursor is 0.50° - 0.65°; (4) The diffraction peak intensity I of the precursor on the (101) crystal plane (101) The diffraction peak intensity I (001) Ratio I (101) / I (001) 0.97-1.10; (5) The number of wafers N of the precursor on the (101) crystal plane (101) 50-80, N (101) =D (101) / d (101) , d (101) represents the interplanar spacing on the (101) crystal plane.

3. The lithium-ion battery positive electrode material precursor according to claim 1, characterized in that: Meet at least one of the following conditions: ① The average value of the absolute value of the relative deviation 丨Ma丨 of the length of the primary particle ≤ 40%, and the average value of the absolute value of the relative deviation 丨Mb丨 of the width of the primary particle ≤ 40%, wherein, a is the length of the primary particle, b is the width of the primary particle, is the average length of the primary particles, is the average value of the width of the primary particle, 丨Ma丨 and 丨Mb丨 are calculated by Formula ① and Formula ② respectively, Official 1: Formula 2: ② The precursor includes for the primary particle, wherein, a is the length of the primary particle, b is the width of the primary particle, is the average length of the primary particles, is the average value of the width of the primary particle.

4. The lithium-ion battery positive electrode material precursor according to any one of claims 1 to 3, characterized in that: Meet at least one of the following conditions: A. The chemical formula of the precursor is Ni x M 1-x (OH)2, wherein 0≤x<1, and M is at least one of Co, Mn, Al, Ti, Zr, Mo, Cr, W, B, Mg, Ba, Nb or Sr; B. The chemical formula of the precursor is Ni y Co z M 1 w M 2 v (OH)2, where 0≤y<1, 0≤z<0.6, y+z+w+v=1; M 1 is Mn and / or Al; M 2 At least one of Ti, Zr, Mo, Cr, W, B, Mg, Ba, Nb or Sr; C. The particle size D50 of the secondary particles of the precursor is 8 - 22 μm; D. The specific surface area of ​​the precursor is 10-15m 2 / g; E. The tap density TD of the precursor is 1.8-2.1 g / cm 3 .

5. The lithium-ion battery positive electrode material precursor according to claim 4, characterized in that: Meet at least one of the following conditions: Ⅰ. The precursor satisfies Formula 4, Formula 4: 2.30≤D (100) / D (101) ≤2.70; Ⅱ. The precursor satisfies Formula 5, Formula 5: 1.90≤D (100) / D (001) ≤2.40, III. Number of wafers N of the precursor on the (101) crystal plane (101) 60-70; IV. Grain size of the precursor on the (001) crystal plane V. Grain size of the precursor on the (101) crystal plane VI. Average grain size of the precursor VII. The precursor includes for the primary particle, wherein, a is the length of the primary particle, b is the width of the primary particle, is the average length of the primary particles, is the average value of the width of the primary particle; Ⅷ. The chemical formula of the precursor is Ni x M 1-x (OH)2, wherein 0.6≤x<1, and M is at least one of Co, Mn, Al, Ti, Zr, Mo, Cr, W, B, Mg, Ba, Nb or Sr; IX. The chemical formula of the precursor is Ni y Co z M 1 w M 2 v (OH)2, where 0.6≤y<1, 0≤z<0.6, y+z+w+v=1; M 1 is Mn and / or Al; M 2 At least one of Ti, Zr, Mo, Cr, W, B, Mg, Ba, Nb or Sr; Ⅹ. The chemical formula of the precursor is Ni y Co z M 1 w M 2 v (OH)2, where 0.6≤y<1, 0≤z<0.6, 0≤w≤0.4, 0≤v≤0.1, y+z+w+v=1; M 1 is Mn and / or Al; M 2 It is at least one of Ti, Zr, Mo, Cr, W, B, Mg, Ba, Nb or Sr.

6. A method for preparing a lithium-ion battery positive electrode material precursor according to any one of claims 1 to 5, characterized in that: Comprising: Adding raw materials including a metal salt solution, a precipitant, and a complexing agent into a first bottom liquid, and performing a first reaction according to a first predetermined procedure until crystal nuclei are obtained; Preparing a second bottom liquid with the materials including the metal salt solution, the precipitant, the complexing agent, and the crystal nuclei, adding the metal salt solution, the precipitant, and the complexing agent into the second bottom liquid, and performing a second reaction according to a second predetermined procedure until the precursor is obtained; wherein, the first bottom liquid and the second bottom liquid each independently include water, the precipitant, and the complexing agent.

7. The method for preparing a positive electrode material precursor for a lithium-ion battery according to claim 6, characterized in that: Meet at least one of the following conditions: a. The first predetermined procedure includes: after the start of the first reaction, gradually reduce the pH value during the first reaction process, and maintain the final pH value of the first reaction within the range of 9 - 11; b. The second predetermined procedure includes: after the initial start of the second reaction, adjust the pH value of the second reaction, and maintain the final pH of the second reaction within the range of 10 - 12.

8. The method for preparing a positive electrode material precursor for a lithium ion battery according to claim 6 or 7, characterized in that: Meet at least one of the following conditions: c. The particle size D50 of the crystal nuclei is 3 - 10 μm; d. The pH values of the first bottom liquid and the second bottom liquid are each independently 10 - 12, and the ammonia concentrations of the first bottom liquid and the second bottom liquid are each independently 1 - 15 g / L; e. During the first reaction process, the flow rate of the metal salt solution is 1 - 5% / h of the volume of the reaction vessel, the flow rate of the precipitant is 0.35 - 1.85% / h of the volume of the reaction vessel, and the flow rate of the complexing agent is 0.03 - 0.15% / h of the volume of the reaction vessel; f. During the second reaction, the flow rate of the metal salt solution is 1-5% / h of the volume of the reaction container, the flow rate of the precipitant is 0.35-1.85% / h of the volume of the reaction container, and the flow rate of the complexing agent is 0.03-0.15% / h of the volume of the reaction container; g. The temperature of the first reaction and the second reaction are each independently 60-80° C.; h. During the first reaction and the second reaction, the mother liquor is continuously discharged, and the discharge amount is equal to the total feed amount; i. After the second reaction is completed, post-processing is also included: the product of the second reaction is subjected to solid-liquid separation, drying, and sieving for demagnetization.

9. A positive electrode material for a lithium ion battery, characterized in that: The raw material of the positive electrode material includes the lithium ion battery positive electrode material precursor according to any one of claims 1 to 5.

10. A lithium ion battery, characterized in that: The lithium-ion battery comprises the lithium-ion battery positive electrode material according to claim 9.

11. A lithium battery device, characterized in that: Includes the lithium ion battery as claimed in claim 10.

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