Preparation method of coarse nickel hydroxide with short crystal grains

Abstract

The invention provides a preparation method of coarse nickel hydroxide with short crystal grains, and belongs to the field of new energy battery materials, the preparation method comprises the following steps: pumping a nickel salt solution, liquid caustic soda and ammonia water into a reaction kettle, and carrying out first coprecipitation reaction under the conditions of an ammonia value A1 and a stirring rotating speed R1 to obtain first slurry; carrying out second coprecipitation reaction under the conditions that the ammonia value is A2 and the stirring rotating speed is R2 to obtain second slurry; performing a third coprecipitation reaction under the conditions that the ammonia value is A3 and the stirring rotating speed is R3 to obtain third slurry; aging, washing and drying the third slurry to obtain nickel hydroxide; wherein the ammonia value A1 is 10-12 g / L, A1 < gt >; a2gt; a3; the stirring rotating speed R1 is 180-240 rpm, and the stirring rotating speed R1 is R1gt; r2gt; and R3. Through the synergistic effect of ammonia value regulation and control and rotating speed regulation and control, accurate regulation and control of nickel hydroxide crystal grain morphology are achieved, and the physical and chemical properties of the material are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of new energy battery materials technology, specifically to a method for preparing nickel hydroxide with short and coarse grains. Background Technology

[0002] In the field of energy storage and conversion, nickel hydroxide is currently the most representative positive electrode active material in nickel-based alkaline secondary batteries, and its grain morphology and particle size play a decisive role in electrochemical performance. Insufficient control over grain morphology easily leads to the formation of agglomerates with cracks or irregular particles on the surface, resulting in a small specific surface area, long ion diffusion paths, and low utilization of electrochemical active sites.

[0003] Currently, the main methods for synthesizing nickel hydroxide include coprecipitation, hydrothermal synthesis, and sol-gel synthesis. Traditional coprecipitation is simple and easy to scale up, but the reaction system lacks an effective morphology / particle size control mechanism. The products generally suffer from irregular grain morphology, wide particle size distribution, and severe agglomeration, resulting in low specific capacity and poor cycle stability, making it difficult to meet the requirements of high-performance devices. Traditional hydrothermal synthesis can improve crystallinity and morphology uniformity to some extent through high-temperature and high-pressure conditions, but the reaction requires high temperatures and pressures, leading to high equipment investment and energy consumption, as well as significant safety risks. Furthermore, to obtain specific morphologies, surfactants or hard templates must be introduced, resulting in complex post-processing and high overall costs. Traditional sol-gel synthesis can achieve molecular-level mixing at low temperatures, producing high-purity products, but it requires large amounts of organic solvents and complexing agents, has a long process cycle, high wastewater treatment costs, and limits large-scale production.

[0004] Therefore, it is of great significance to provide a synthesis process for nickel hydroxide that does not require complex templates, has mild reaction conditions, and can precisely control the morphology of nickel hydroxide grains in order to obtain nickel hydroxide materials with uniform morphology. Summary of the Invention

[0005] In view of the technical problems existing in the background art, the present invention provides a method for preparing nickel hydroxide with short and coarse grains, aiming to solve the technical problems of irregular grain morphology, small specific surface area, easy formation of agglomerates and surface cracks in existing nickel hydroxide.

[0006] In a first aspect, the present invention provides a method for preparing short-grained nickel hydroxide, comprising the following steps: Nickel salt solution, liquid alkali, and ammonia water are pumped into a reactor and subjected to a first coprecipitation reaction under conditions of ammonia value A1 and stirring speed R1 to obtain a first slurry; a second coprecipitation reaction is carried out under conditions of ammonia value A2 and stirring speed R2 to obtain a second slurry; a third coprecipitation reaction is carried out under conditions of ammonia value A3 and stirring speed R3 to obtain a third slurry; the third slurry is then aged, washed, and dried to obtain nickel hydroxide; Among them, the ammonia value A1 is 10~12g / L, A1>A2>A3; the stirring speed R1 is 180~240rpm, R1>R2>R3.

[0007] Preferably, the ammonia value A2 is 8~10g / L and the ammonia value A3 is 7~8g / L.

[0008] Preferably, the stirring speed R2 is 160~180 rpm and the stirring speed R3 is 120~160 rpm.

[0009] Preferably, the pH in the first coprecipitation reaction is 11.0~11.4, and the median particle size D of the first slurry is... 50 The size is 1~3μm.

[0010] Preferably, the pH in the second coprecipitation reaction is 10.6~11.0, and the median particle size D of the second slurry is... 50 It is 5~8μm.

[0011] Preferably, the pH in the third coprecipitation reaction is 10.2~10.6, and the median particle size D of the third slurry is... 50 It is 10~11μm.

[0012] Preferably, before pumping the nickel salt solution, liquid alkali, and ammonia into the reactor, the following steps are also included: adding water, liquid alkali, and ammonia into the reactor as a base solution, controlling the initial pH of the base solution to be 10.4~11.5, and the initial ammonia value to be 10.6~10.8 g / L.

[0013] Preferably, the temperatures of the first coprecipitation reaction, the second coprecipitation reaction, and the third coprecipitation reaction are each independently controlled at 50~60℃.

[0014] Preferably, the drying process involves drying at 120-150℃ for 2-4 hours.

[0015] Secondly, the present invention provides a short-grained nickel hydroxide, which is prepared by the method for preparing short-grained nickel hydroxide described in the first aspect.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention effectively controls the growth process of nickel hydroxide grains through a multi-stage co-precipitation reaction, combined with gradient changes in ammonia value and stirring speed, resulting in shorter, thicker, and more uniform grain morphology. This method eliminates the need for complex templates or harsh reaction conditions, enabling precise control of grain morphology and size under mild conditions, significantly improving key performance indicators such as specific surface area, tap density, and compacted density. Furthermore, the process is simple to operate, requires minimal equipment, and is suitable for large-scale industrial production, demonstrating high economic efficiency and practicality. Attached Figure Description

[0017] Figure 1 Here is a SEM image of the nickel hydroxide product obtained in Example 1; Figure 2 SEM image of the nickel hydroxide product obtained in Comparative Example 1; Figure 3 SEM image of the nickel hydroxide product obtained in Comparative Example 2; Figure 4 SEM image of the nickel hydroxide product obtained in Comparative Example 3; Figure 5 This is a SEM image of the nickel hydroxide product obtained in Comparative Example 4. Detailed Implementation

[0018] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0019] To address the technical problems of irregular grain morphology, easy agglomeration, and surface cracks in existing nickel hydroxide processes, this invention provides a method for preparing short and coarse-grained nickel hydroxide. By synergistically controlling ammonia value and rotation speed, precise control of nickel hydroxide grain morphology is achieved, avoiding reliance on complex templates or harsh reaction conditions in traditional processes. The resulting nickel hydroxide exhibits a uniform short and coarse grain structure, significantly improving key performance indicators such as specific surface area, tap density, and compaction density.

[0020] In a first aspect, embodiments of the present invention provide a method for preparing short-grained nickel hydroxide, comprising the following steps: Nickel salt solution, liquid alkali, and ammonia water are pumped into a reactor and subjected to a first coprecipitation reaction under conditions of ammonia value A1 and stirring speed R1 to obtain a first slurry; a second coprecipitation reaction is carried out under conditions of ammonia value A2 and stirring speed R2 to obtain a second slurry; a third coprecipitation reaction is carried out under conditions of ammonia value A3 and stirring speed R3 to obtain a third slurry; the third slurry is then aged, washed, and dried to obtain nickel hydroxide; Among them, the ammonia value A1 is 10~12g / L, A1>A2>A3; the stirring speed R1 is 180~240rpm, R1>R2>R3.

[0021] In the technical solution of this invention embodiment, precise control of crystal growth is achieved through a carefully designed ammonia value gradient reduction mechanism: the high ammonia stage suppresses free Ni by forming a stable nickel-ammonia complex. 2+Concentration, reducing nucleation rate, and optimizing the number of crystal nuclei: A higher ammonia value during the nucleation stage effectively suppresses excessive micronization; as the crystal growth stage progresses, the ammonia value is gradually reduced to a moderate level to promote lateral crystal growth; finally, during the ripening stage, the ammonia value is lowered to a lower level, reducing surface energy to optimize the densification process and prevent surface cracking. Simultaneously, a gradient speed reduction mechanism is implemented to create a synergistic effect: initially, high-speed, strong mechanical stirring enhances mass transfer, ensuring the homogeneity of the reaction system, avoiding size dispersion caused by local supersaturation, inhibiting nucleus aggregation, and forming monodisperse nanocrystals; in the middle stage, adjusting to a moderate speed effectively suppresses abnormal dendrite growth; and in the later stage, reducing to a low speed significantly reduces grain breakage. This dual-gradient control strategy achieves precise control of crystal morphology and structure.

[0022] Furthermore, in some embodiments, the ammonia value A2 is 8~10 g / L, and the ammonia value A3 is 7~8 g / L.

[0023] Furthermore, in some embodiments, the stirring speed R2 is 160~180 rpm and the stirring speed R3 is 120~160 rpm.

[0024] In the technical solution of this invention, the preferred ammonia value range and stirring speed range for each stage were summarized through numerous experiments. Operating within these ranges can further optimize the grain morphology and properties of nickel hydroxide. For example, when the ammonia value A1 is 10~12 g / L and the stirring speed R1 is maintained at 180~240 rpm, the uniformity of the crystal nucleation stage can be ensured, avoiding excessively large or small crystal nuclei, thus laying a good foundation for subsequent crystal growth. Ammonia value A2 of 8~10 g / L and stirring speed R2 of 160~180 rpm contribute to the stable lateral expansion of the crystals, reducing defects during crystal growth. Finally, when the ammonia value A3 is 7~8 g / L and the stirring speed R3 is 120~160 rpm, the crystal structure can be made more compact, increasing the tap density and compaction density of the material.

[0025] Furthermore, in some embodiments, the pH in the first coprecipitation reaction is 11.0~11.4, and the median particle size D of the first slurry is... 50 The size is 1~3μm.

[0026] Furthermore, in some embodiments, the pH in the second coprecipitation reaction is 10.6~11.0, and the median particle size D of the second slurry is... 50 It is 5~8μm.

[0027] Furthermore, in some embodiments, the pH in the third coprecipitation reaction is 10.2~10.6, and the median particle size D of the third slurry is... 50 It is 10~11μm.

[0028] In the technical solution of this invention embodiment, the growth process of nickel hydroxide is further optimized by precisely controlling the pH value and termination particle size at each stage. The higher pH value in the first coprecipitation reaction is conducive to the formation of stable crystal nuclei, while the smaller initial particle size ensures the basic uniformity of crystal growth. The moderately lowered pH value in the second coprecipitation reaction promotes the lateral expansion of the crystals, causing the particle size to gradually increase and form a short, thick structure. The further lowered pH value in the third coprecipitation reaction helps to densify the crystal structure, ultimately obtaining nickel hydroxide material with ideal morphology and properties.

[0029] Furthermore, in some embodiments, before pumping the nickel salt solution, liquid alkali, and ammonia into the reactor, the following steps are also included: adding water, liquid alkali, and ammonia into the reactor as a base liquid, controlling the initial pH of the base liquid to be 10.4~11.5, and the initial ammonia value to be 10.6~10.8 g / L.

[0030] In the technical solution of this invention embodiment, the pre-adjustment of the pH and ammonia values ​​of the base liquid provides ideal initial conditions for subsequent reactions, ensuring the uniformity of the crystal nucleation stage.

[0031] Furthermore, in some embodiments, the temperatures of the first coprecipitation reaction, the second coprecipitation reaction, and the third coprecipitation reaction are each independently controlled at 50~60°C.

[0032] In the technical solution of this invention embodiment, by controlling the reaction temperature within the range of 50~60℃, the stable progress of the coprecipitation reaction at each stage is ensured, while avoiding the adverse effects of high temperature on grain morphology.

[0033] Furthermore, in some embodiments, the nickel salt solution is prepared at a water temperature of 50-80°C, which can help the nickel salt to dissolve fully.

[0034] Furthermore, in some embodiments, the concentration of the nickel salt solution is 120 g / L, and the flow rate of the nickel salt solution pumped into the reactor is 280 L / h.

[0035] Furthermore, in some embodiments, the drying process specifically involves drying at 120-150°C for 2-4 hours.

[0036] Secondly, embodiments of the present invention provide a short-grained nickel hydroxide, which is prepared by the method for preparing short-grained nickel hydroxide described in the first aspect.

[0037] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0038] Example 1 A method for preparing short-grained nickel hydroxide includes the following steps: (1) Prepare a nickel sulfate solution with a concentration of 120 g / L (the water temperature during preparation is 60℃), a liquid alkali with a mass concentration of 31%, and ammonia water with a mass concentration of 13% as complexing agents; (2) Add deionized water to the reactor, add an appropriate amount of liquid alkali with a mass concentration of 31%, and ammonia water with a mass percentage concentration of 13% as the reaction base liquid. Control the initial pH of the reaction base liquid to be 11.45 and the ammonia concentration to be 10.62 g / L. Raise the temperature to 50℃ and maintain it stable. (3) Crystal nucleation: The stirring speed was set to 200 rpm. The nickel sulfate solution, 31% liquid alkali and ammonia water prepared in (1) were injected into the reactor in parallel through a metering pump for co-precipitation reaction. The feed flow rate of the nickel sulfate solution was controlled to be 280 L / h and the reaction temperature was 50℃. By adjusting the amount of liquid alkali and ammonia water, the ammonia value of the slurry in the reactor was controlled to be 10 g / L and the pH value to be 11.2 ± 0.1. The reaction was carried out until the particles D 50 The first slurry was obtained after reaching a thickness of 3μm. (4) Growth period: Reduce the stirring speed to 160 rpm, and control the ammonia value of the slurry in the reactor to 9.5 g / L and the pH value to 10.9 ± 0.1 by adjusting the amount of NaOH and ammonia water. The reaction continues until the particles reach particle size D. 50 Continue to grow to 8μm to obtain the second slurry; (5) Maturation period: Reduce the stirring speed to 120 rpm, and control the ammonia value of the slurry in the reactor to 7.5 g / L and the pH value to 10.8 ± 0.05 by adjusting the amount of NaOH and ammonia water. The reaction continues until the particles reach particle size D. 50 The material continued to grow to 11.0 μm, yielding the third slurry. (6) After aging the third pulp for 1 hour, it is washed in three stages of countercurrent washing until Na is reached. + <150ppm, SO4 2- <150ppm, after vacuum drying at 140℃ for 2.5h, nickel hydroxide product is obtained.

[0039] Example 2 A method for preparing short-grained nickel hydroxide includes the following steps: (1) Prepare a nickel sulfate solution with a concentration of 120 g / L (the water temperature during preparation is 60℃), a liquid alkali with a mass concentration of 31%, and ammonia water with a mass concentration of 13% as complexing agents; (2) Add deionized water to the reaction vessel, add an appropriate amount of liquid alkali with a mass concentration of 31%, and ammonia water with a mass percentage concentration of 13% as the reaction base liquid. Control the initial pH of the reaction base liquid to be 10.4 and the ammonia concentration to be 10.6 g / L. Raise the temperature to 50℃ and maintain it stable. (3) Crystal nucleation: The stirring speed was set to 240 rpm. The nickel sulfate solution, 31% liquid alkali and ammonia water prepared in (1) were injected into the reactor in parallel through a metering pump for co-precipitation reaction. The feed flow rate of the nickel sulfate solution was controlled to be 280 L / h and the reaction temperature was 50℃. By adjusting the amount of liquid alkali and ammonia water, the ammonia value of the slurry in the reactor was controlled to be 12 g / L and the pH value to be 11.2 ± 0.1. The reaction was carried out until the particles D 50 The first slurry was obtained when the particle size reached 2μm. (4) Growth period: Reduce the stirring speed to 180 rpm, and control the ammonia value of the slurry in the reactor to 10 g / L and the pH value to 10.9 ± 0.1 by adjusting the amount of NaOH and ammonia water. The reaction continues until the particles reach particle size D. 50 Continue to grow to 8μm to obtain the second slurry; (5) Maturation period: Reduce the stirring speed to 160 rpm, and control the ammonia value of the slurry in the reactor to 8 g / L and the pH value to 10.8 ± 0.05 by adjusting the amount of NaOH and ammonia water, until the reaction reaches particle size D. 50 The material continued to grow to 10.0 μm, yielding the third slurry. (6) After aging the third pulp for 1 hour, it is washed in three stages of countercurrent washing until Na is reached. + <150ppm, SO4 2- <150ppm, after vacuum drying at 140℃ for 2.5h, nickel hydroxide product is obtained.

[0040] Example 3 A method for preparing short-grained nickel hydroxide includes the following steps: (1) Prepare a nickel sulfate solution with a concentration of 120 g / L (the water temperature during preparation is 60℃), a liquid alkali with a mass concentration of 31%, and ammonia water with a mass concentration of 13% as complexing agents; (2) Add deionized water to the reaction vessel, add an appropriate amount of liquid alkali with a mass concentration of 31%, and ammonia water with a mass percentage concentration of 13% as the reaction base liquid. Control the initial pH of the reaction base liquid to be 10.4 and the ammonia concentration to be 10.6 g / L. Raise the temperature to 50℃ and maintain it stable. (3) Crystal nucleation: The stirring speed was set to 180 rpm. The nickel sulfate solution, 31% liquid alkali and ammonia water prepared in (1) were injected into the reactor in parallel through a metering pump for co-precipitation reaction. The feed flow rate of the nickel sulfate solution was controlled to be 280 L / h and the reaction temperature was 50℃. By adjusting the amount of liquid alkali and ammonia water, the ammonia value of the slurry in the reactor was controlled to be 8 g / L and the pH value to be 11.2 ± 0.1. The reaction was carried out until the particles D 50 The first slurry was obtained when the particle size reached 2μm. (4) Growth period: Reduce the stirring speed to 160 rpm, and control the ammonia value of the slurry in the reactor to 8 g / L and the pH value to 10.9 ± 0.1 by adjusting the amount of NaOH and ammonia water. The reaction continues until the particles reach particle size D. 50 Continue to grow to 6μm to obtain the second slurry; (5) Maturation period: Reduce the stirring speed to 120 rpm, and control the ammonia value of the slurry in the reactor to 7 g / L and the pH value to 10.8 ± 0.05 by adjusting the amount of NaOH and ammonia water, until the reaction reaches particle size D. 50 The material continued to grow to 10.0 μm, yielding the third slurry. (6) After aging the third pulp for 1 hour, it is washed in three stages of countercurrent washing until Na is reached. + <150ppm, SO4 2- <150ppm, after vacuum drying at 140℃ for 2.5h, nickel hydroxide product is obtained.

[0041] Comparative Example 1 The difference between this comparative example and Example 1 is that there was no ammonia gradient control during the preparation process, and the ammonia value was kept constant at 12.0 g / L throughout. All other parameters are the same as in Example 1.

[0042] Comparative Example 2 The difference from Example 1 is that a constant rotation speed of 160 rpm was used throughout the preparation process. All other parameters are the same as in Example 1.

[0043] Comparative Example 3 The difference from Example 1 is that the initial ammonia value in step (3) of the crystal nucleation stage is increased to 14.0 g / L. The other parameters are the same as in Example 1.

[0044] Comparative Example 4 The difference from Example 1 is that the stirring speed is set to 330 rpm in step (3) of the crystal nucleus generation stage.

[0045] The nickel hydroxide products obtained in each embodiment and comparative example were characterized and tested. The specific test methods are as follows: (1) Particle size test: D was tested using a Malvern laser particle size analyzer. 10 D 50 D 90And according to formula (D) 90 -D 10 ) / D 50 The particle size distribution width K was calculated. 90 .

[0046] (2) Specific surface area (SSA) test: The test was conducted using a fully automated nitrogen adsorption specific surface area tester.

[0047] (3) Tap density (TD) test: The test is performed using a tap density meter.

[0048] (4) Compacted density (AD) test: The test is conducted using a compaction density meter.

[0049] (5) Morphology test: Morphology test was performed using a scanning electron microscope.

[0050] The test results of the examples and comparative examples are shown in Table 1.

[0051] Table 1

[0052] As shown in Table 1, the short and coarse nickel hydroxide prepared by this invention has a high specific surface area, tap density and compaction density, and a relatively uniform particle size distribution.

[0053] Figure 1 The image shows a SEM image of the nickel hydroxide product obtained in Example 1. It was observed that the primary grains were short and coarse with a thickness-to-diameter ratio of 0.83, and no micro-powder was observed.

[0054] Figure 2 The image shows a SEM image of the nickel hydroxide product prepared in Comparative Example 1. It reveals slender dendrites and micro-powder agglomeration.

[0055] Figure 3 The image shows a SEM image of the nickel hydroxide product prepared in Comparative Example 2. The image reveals grain fracture and irregular fragments.

[0056] Figure 4 The SEM image of the nickel hydroxide product prepared in Comparative Example 3 shows that the primary grains are slender with a thickness-to-diameter ratio of 0.35, which does not match the target short and coarse grains, and the specific surface area is significantly smaller.

[0057] Figure 5 The SEM image of the nickel hydroxide product prepared in Comparative Example 4 shows that the primary grains are slender with a thickness-to-diameter ratio of 0.27, which does not match the target short and coarse grains, and the specific surface area is significantly smaller.

[0058] In summary, the preparation method provided in the above embodiments of this invention successfully achieves precise control over the grain morphology of nickel hydroxide, while avoiding the dependence on complex templates or harsh reaction conditions in traditional processes. The resulting material has a uniform, short, and coarse grain structure, significantly improving key performance indicators such as specific surface area, tap density, and compaction density, thus providing a superior basic material for electrochemical applications. Furthermore, this method is simple to operate, with mild reaction conditions, suitable for large-scale industrial production, and possesses high practicality and economic efficiency.

[0059] It should be noted that the present invention is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments that have the same structure and perform the same effects as the technical concept within the scope of the present invention are included within the scope of the present invention. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of the present invention, are also included within the scope of the present invention.

Claims

1. A method for preparing nickel hydroxide with short, coarse grains, characterized in that, Includes the following steps: Nickel salt solution, liquid alkali and ammonia water are pumped into a reactor and the first coprecipitation reaction is carried out under the conditions of ammonia value A1 and stirring speed R1 to obtain the first slurry. A second coprecipitation reaction was carried out under conditions of ammonia value A2 and stirring speed R2 to obtain a second slurry; a third coprecipitation reaction was carried out under conditions of ammonia value A3 and stirring speed R3 to obtain a third slurry; the third slurry was aged, washed, and dried to obtain nickel hydroxide; Among them, the ammonia value A1 is 10~12g / L, A1>A2>A3; the stirring speed R1 is 180~240rpm, R1>R2>R3.

2. The method for preparing short-grained nickel hydroxide according to claim 1, characterized in that, The ammonia value A2 is 8~10 g / L, and the ammonia value A3 is 7~8 g / L.

3. The method for preparing short-grained nickel hydroxide according to claim 1, characterized in that, The stirring speed R2 is 160~180 rpm, and the stirring speed R3 is 120~160 rpm.

4. The method for preparing short-grained nickel hydroxide according to claim 1, characterized in that, The pH in the first coprecipitation reaction is 11.0~11.4, and the median particle size D of the first slurry is... 50 The size is 1~3μm.

5. The method for preparing short-grained nickel hydroxide according to claim 1, characterized in that, The pH in the second coprecipitation reaction is 10.6~11.0, and the median particle size D of the second slurry is... 50 It is 5~8μm.

6. The method for preparing short-grained nickel hydroxide according to claim 1, characterized in that, The pH in the third coprecipitation reaction is 10.2~10.6, and the median particle size D of the third slurry is... 50 It is 10~11μm.

7. The method for preparing short-grained nickel hydroxide according to claim 1, characterized in that, Before pumping the nickel salt solution, liquid alkali, and ammonia into the reactor, the process includes the following steps: adding water, liquid alkali, and ammonia into the reactor as a base solution, controlling the initial pH of the base solution to be 10.4~11.5, and the initial ammonia value to be 10.6~10.8 g / L.

8. The method for preparing short-grained nickel hydroxide according to claim 1, characterized in that, The temperatures of the first coprecipitation reaction, the second coprecipitation reaction, and the third coprecipitation reaction are each independently controlled at 50~60℃.

9. The method for preparing short-grained nickel hydroxide according to claim 1, characterized in that, The drying process involves drying at 120-150℃ for 2-4 hours.

10. A type of nickel hydroxide with short, coarse grains, characterized in that, It is prepared by the method for preparing short and coarse nickel hydroxide according to any one of claims 1 to 9.

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