Positive electrode material of nickel-metal hydride battery, preparation method of positive electrode material, nickel-metal hydride battery and electric equipment

Abstract

The invention provides a nickel-metal hydride battery positive electrode material and a preparation method thereof, a nickel-metal hydride battery and electric equipment, the nickel-metal hydride battery positive electrode material is nickel-containing hydroxide doped with cobalt element and zinc element, the nickel-metal hydride battery positive electrode material comprises secondary particles composed of a plurality of primary particles, and the section porosity of the secondary particles is less than or equal to 3.0%. The nickel-metal hydride battery positive electrode material provided by the embodiment of the invention is doped with the cobalt element and the zinc element, attenuation of the capacity and the service life of the positive electrode material at high temperature can be slowed down through the doped elements, and the secondary particles are integrally of a compact structure, have few internal pores and are not easy to crack when bearing stress, so that the nickel-metal hydride battery positive electrode material is better in structural stability, and the service life is prolonged. And the cycle performance and the capacity retention ratio can be considered.

Description

Technical Field

[0001] The present application relates to the technical field of nickel-hydrogen batteries, and in particular to a nickel-hydrogen battery positive electrode material and a preparation method thereof, a nickel-hydrogen battery and electrical equipment. Background Art

[0002] Nickel-metal hydride batteries have the characteristics of low temperature performance, good cycle life, low maintenance cost, good safety, etc., and their application is becoming more and more extensive. Since the positive electrode material of nickel-metal hydride batteries has a direct impact on the performance of nickel-metal hydride batteries, the performance of nickel-metal hydride batteries can be further optimized by improving the positive electrode material of nickel-metal hydride batteries.

[0003] The current positive electrode materials of nickel-hydrogen batteries have defects such as structural instability and easy cracking when subjected to stress, which limits the cycle performance and capacity retention rate of nickel-hydrogen batteries. Summary of the invention

[0004] The present application provides a nickel-hydrogen battery positive electrode material and a preparation method thereof, a nickel-hydrogen battery and electrical equipment to solve the problems of the nickel-hydrogen battery positive electrode material having an unstable structure and being prone to cracking when subjected to stress.

[0005] An embodiment of the present application provides a nickel-hydrogen battery positive electrode material. The nickel-hydrogen battery positive electrode material is a nickel hydroxide doped with cobalt and zinc elements. The nickel-hydrogen battery positive electrode material includes secondary particles composed of multiple primary particles, and the cross-sectional porosity of the secondary particles is ≤3.0%.

[0006] In some embodiments of the present application, the cross-sectional porosity of the secondary particles is 0.1%-3.0%, preferably 0.1%-1.5%.

[0007] In some embodiments of the present application, the positive electrode material of the nickel-hydrogen battery satisfies at least one of the following conditions ae:

[0008] a. The primary particles on the surface of the secondary particles are spindle-shaped or coarse-grained;

[0009] b. The aspect ratio of the primary particles on the surface of the secondary particles is (1.5-6):1;

[0010] c. The length of the primary particles on the surface of the secondary particles is 200nm-800nm, preferably 400nm-700nm;

[0011] d. The width of the primary particles on the surface of the secondary particles is 100nm-400nm, preferably 100nm-300nm;

[0012] e. The primary particles inside the secondary particles are arranged radially along the radial direction of the secondary particles.

[0013] In some embodiments of the present application, the positive electrode material of the nickel-hydrogen battery satisfies at least one of the following conditions fn:

[0014] f. The average particle size D50 of the secondary particles is 3.0 μm-20.0 μm, preferably 9.0 μm-11.0 μm;

[0015] h. The particle size distribution Span value of the secondary particles is 1.20-1.60, preferably 1.30-1.50;

[0016] i. The sphericity of the secondary particles is 0.85-1.00, preferably 0.85-0.95;

[0017] j. The specific surface area of ​​secondary particles is 5m 2 / g-10m 2 / g;

[0018] k. The tap density of the secondary particles is 2.10 g / cm 3 -2.40g / cm 3 , preferably 2.20g / cm 3 -2.40g / cm 3 ;

[0019] 1. The volume change rate of the secondary particles under a pressure of 5KN is ≤30%;

[0020] m. The general chemical formula of the positive electrode material of nickel-hydrogen battery is Ni x Co y Zn z (OH)2, where 0.8≤x<0.98, 0.01 <y≤0.1,0.01<z≤0.1,x+y+z=1;

[0021] n. Divide the cross section of the secondary particles into several equal parts according to area, and the cross-sectional porosity of each cross section is ≤3.0%, preferably ≤1.5%.

[0022] Another embodiment of the present application provides a method for preparing a positive electrode material for a nickel-hydrogen battery, comprising the following steps: mixing a solvent, a precipitant and a complexing agent to obtain a base liquid; adding a metal salt solution containing nickel, cobalt and zinc, a precipitant and a complexing agent to the base liquid for a co-precipitation reaction, maintaining the solid content of the reaction system at 150 g / L-400 g / L until a reaction product is obtained; and post-treating the reaction product to obtain a positive electrode material for a nickel-hydrogen battery.

[0023] In some embodiments of the present application, the preparation method satisfies at least one of the following conditions ①-⑦:

[0024] ① The metal salt includes at least one of sulfate, nitrate, acetate and chloride;

[0025] ②. The total concentration of the metal salt solution is 100g / L-130g / L;

[0026] ③. The precipitant includes at least one of a sodium hydroxide solution and a potassium hydroxide solution;

[0027] ④. The mass percentage concentration of the precipitant is 20%-35%;

[0028] ⑤. The complexing agent includes at least one of ammonia water, ammonium bicarbonate solution, ammonium carbonate solution, EDTA solution (ethylenediaminetetraacetic acid solution), ethylenediamine solution, sodium citrate solution and ammonium sulfate solution;

[0029] ⑥ The mass percentage concentration of the complexing agent is 10%-25%;

[0030] ⑦. The solvent includes water.

[0031] In some embodiments of the present application, the temperature of the base liquid is 50°C-80°C; and / or the pH value of the base liquid is 10.00-12.00; and / or the complexing agent is ammonia water, and the ammonia concentration of the base liquid is 10g / L-20g / L.

[0032] In some embodiments of the present application, the preparation method satisfies at least one of the following conditions (1)-(8):

[0033] (1) The feeding rate of the metal salt solution is 5.5% / h-9.5% / h of the reaction vessel volume;

[0034] (2) The feed rate of the precipitant in the coprecipitation reaction is 2.5% / h-5% / h of the volume of the reaction vessel;

[0035] (3) The feeding rate of the complexing agent for the coprecipitation reaction is 0.1% / h-2.5% / h of the volume of the reaction vessel;

[0036] (4) The stirring speed of the coprecipitation reaction is 400r / min-700r / min;

[0037] (5) The reaction temperature of the coprecipitation reaction is the same as that of the base solution and is 50°C-80°C;

[0038] (6) The reaction pH of the coprecipitation reaction is the same as the pH of the base solution and is 10.00-12.00;

[0039] (7) The complexing agent is ammonia water, and the ammonia concentration of the coprecipitation reaction is the same as that of the base solution and is 10g / L-20g / L;

[0040] (8) The solid content of the reaction system of the coprecipitation reaction is 200 g / L-320 g / L.

[0041] Yet another embodiment of the present application provides a nickel-hydrogen battery, comprising any one of the above nickel-hydrogen battery positive electrode materials.

[0042] Yet another embodiment of the present application provides an electrical device, including the above nickel-hydrogen battery.

[0043] The positive electrode material of the nickel-hydrogen battery provided in the embodiment of the present application is doped with cobalt and zinc elements. By introducing defects and distortions in the lattice through doping elements, the mobility of protons is increased, which is beneficial to improving the charge and discharge efficiency. Cobalt can increase the oxygen evolution overpotential, and zinc will enhance the Ni-O bond of the nickel hydroxide lattice, slowing down the decay of the capacity and life of the positive electrode material at high temperatures. In addition, by controlling the cross-sectional porosity of the secondary particles to be ≤3.0%, the secondary particles are made to have a dense structure as a whole, with few internal pores, and are not easy to crack when subjected to stress. The positive electrode material of the nickel-hydrogen battery has better structural stability, which is beneficial to improving the cycle performance, especially the high-temperature cycle performance. Therefore, the positive electrode material of the nickel-hydrogen battery in the embodiment of the present application is co-doped with cobalt and zinc elements, and the porosity of the secondary particles is controlled within the above-mentioned appropriate range, which is beneficial to taking into account both the cycle performance and the capacity retention rate.

[0044] According to the preparation method provided in the embodiment of the present application, by selecting a suitable metal salt raw material and controlling the steps and conditions of the coprecipitation reaction, the prepared nickel-hydrogen battery positive electrode material is a nickel-cobalt hydroxide doped with Co and Zn, and the cross-sectional porosity of the secondary particles of the nickel-hydrogen battery positive electrode material is ≤3.0%. Therefore, by co-doping Co and Zn in the nickel-containing hydroxide and controlling the cross-sectional porosity of the secondary particles within the above-mentioned suitable range, it is beneficial to take into account both the cycle performance and the rate performance.

[0045] The nickel-hydrogen battery provided according to the embodiment of the present application includes the nickel-hydrogen battery positive electrode material in the above embodiment. Based on the performance of the nickel-hydrogen battery positive electrode material, the nickel-hydrogen battery in the embodiment of the present application can take into account electrochemical properties such as cycle performance and rate performance.

[0046] Additional technical solutions and advantages of the present application will be partially given in the following description, and partially become apparent from the following description, or be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0048] Figure 1 This is a SEM image of the positive electrode material for a nickel-hydrogen battery provided in Example 1 of the present application;

[0049] Figure 2A CP cross-sectional view of the positive electrode material for a nickel-hydrogen battery provided in Example 1 of the present application;

[0050] Figure 3 This is a SEM image of the positive electrode material for a nickel-hydrogen battery provided in Example 2 of the present application;

[0051] Figure 4 A CP cross-sectional view of a positive electrode material for a nickel-hydrogen battery provided in Example 2 of the present application;

[0052] Figure 5 This is a SEM image of the positive electrode material for a nickel-hydrogen battery provided in Example 3 of the present application;

[0053] Figure 6 A CP cross-sectional view of the positive electrode material for a nickel-hydrogen battery provided in Example 3 of the present application;

[0054] Figure 7 This is a SEM image of the positive electrode material of a nickel-hydrogen battery provided in Comparative Example 1 of the present application;

[0055] Figure 8 This is a SEM image of the positive electrode material of a nickel-hydrogen battery provided in Comparative Example 2 of the present application;

[0056] Fig. 9 This is a SEM image of the positive electrode material of a nickel-hydrogen battery provided in Comparative Example 3 of the present application;

[0057] Fig.10 This is a SEM image of the positive electrode material of a nickel-hydrogen battery provided in Comparative Example 4 of the present application;

[0058] Fig.11 This is a CP cross-sectional view of the nickel-hydrogen battery positive electrode material provided in Comparative Example 5 of the present application. DETAILED DESCRIPTION

[0059] "Scope" disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be including end values ​​or not including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following scope can be all expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0060] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0061] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0062] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0063] If there is no special explanation, the "include" and "comprising" mentioned in this application are open-ended or closed-ended. For example, the "include" and "comprising" may mean that other components not listed may also be included or only the listed components may be included or only the listed components may be included.

[0064] If not specifically stated, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0065] The embodiment of the present application provides a positive electrode material for a nickel-hydrogen battery, wherein the positive electrode material for the nickel-hydrogen battery is a nickel hydroxide doped with cobalt and zinc elements, and the positive electrode material for the nickel-hydrogen battery includes secondary particles composed of a plurality of primary particles, and the cross-sectional porosity of the secondary particles is ≤3.0%. The cross-sectional porosity is measured by Avizo software, and the cross-sectional porosity = the pore area on the cross section of the secondary particles / the cross-sectional area of ​​the secondary particles × 100%, and the cross-sectional porosity of the present application is characterized by this method.

[0066] The nickel-hydrogen battery positive electrode material provided in the embodiment of the present application is doped with cobalt (Co) and zinc (Zn). After the two elements of Co and Zn are co-doped, the mobility of protons is increased by introducing defects and distortions in the lattice, and the charge and discharge efficiency is significantly improved. Co can increase the oxygen evolution overpotential and inhibit the occurrence of oxygen evolution side reactions. Zn will enhance the Ni-O bond of the nickel hydroxide lattice, slowing down the decay of the capacity and life of the nickel-hydrogen battery positive electrode material at high temperatures. In addition, by controlling the porosity of the cross section of the secondary particles to be ≤3.0%, the secondary particles are made into a dense structure as a whole, and the internal pore volume accounts for a small proportion, and it is not easy to crack when subjected to stress. The coordination with the doping elements makes the structural stability of the nickel-hydrogen battery positive electrode material better, which is conducive to improving the cycle performance. Therefore, the nickel-hydrogen battery positive electrode material of the embodiment of the present application is co-doped with cobalt and zinc elements, and the porosity of the secondary particles is controlled within the above-mentioned appropriate range, which is conducive to taking into account both the cycle performance and the capacity retention rate.

[0067] For example, in some embodiments, the secondary particles are spherical or quasi-spherical, and the porosity of the secondary particles on any cross section passing through or not passing through the center of the sphere is ≤3.0%. This is beneficial to maintain the structural stability of the secondary particles and improve the filling property of the positive electrode active material, so as to further improve the electrochemical performance such as cycle stability.

[0068] In some embodiments, the porosity of any cross section of the secondary particles is 0.1%-3.0%, preferably 0.1%-1.5%. Exemplarily, the porosity of any cross section of the secondary particles can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3.0% or any value between 0.1%-3.0%. The dense structure can inhibit cracking when the secondary particles are subjected to stress, improve structural stability, and further help to balance cycle performance and capacity retention.

[0069] In some embodiments, the cross section of the secondary particle is divided into several equal parts according to area (such as 3-8 equal-area regions, which can be divided into sector-shaped regions or annular regions of equal area), and the cross-sectional porosity of each cross section is ≤3.0%, preferably ≤1.5%. Thus, on the one hand, the secondary particle presents a dense structure as a whole, and on the other hand, the internal pore distribution of the secondary particle is more uniform, which is further conducive to taking into account both the cycle performance and the capacity retention rate.

[0070] In some embodiments, the primary particles on the surface of the secondary particles are spindle-shaped or granular. In some embodiments, the aspect ratio of the primary particles on the surface of the secondary particles is (1.5-6):1. Among them, the aspect ratio of the primary particles on the surface of the secondary particles is calculated by using Avizo software, taking 5-10 primary particles, testing the length and width of the primary particles on the surface multiple times, and then taking the average value of the length and width of the primary particles. The aspect ratio referred to in this article is characterized by this method (wherein the length of the primary particle is the longest straight-line distance between any two points on the primary particle, and the width is the longest straight-line distance perpendicular to the length direction of the primary particle). Exemplarily, the aspect ratio of the primary particles on the surface of the secondary particles can be 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1 or any value between 1.5:1 and 6:1. The primary particles of this embodiment are short and thick spindle-shaped or coarse granular. The short primary particles with a certain thickness are beneficial to shortening the diffusion path of protons and improving the charging and discharging efficiency. The coarse primary particles have higher strength and better crystallinity, which is beneficial to structural stability. At the same time, since the secondary particles are dense inside, the structural stability can be further improved, which is beneficial to both capacity and circulation.

[0071] In some embodiments, the length of the primary particle on the surface of the secondary particle is 200nm-800nm, preferably 400nm-700nm; illustratively, the length of the primary particle on the surface of the secondary particle can be 200nm, 250nm, 300nm, 350nm, 400nm, 450nm, 500nm, 550nm, 600nm, 650nm, 700nm, 750nm, 800nm ​​or any value between 200nm-800nm. In some embodiments, the width of the primary particle on the surface of the secondary particle is 100nm-400nm, preferably 100nm-300nm; illustratively, the width of the primary particle on the surface of the secondary particle can be 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm or any value between 100nm-400nm. When the length and width of the primary particles on the surface of the secondary particles are respectively within the above-mentioned appropriate ranges, it is beneficial to improve the particle strength and shorten the proton diffusion path, thereby further optimizing the electrochemical performance.

[0072] In some embodiments, the secondary particles are spherical or quasi-spherical, and the primary particles inside the secondary particles are radially arranged along the radial direction of the secondary particles, so as to improve the proton conductivity, thereby improving the cycle performance and charge and discharge efficiency.

[0073] In some embodiments, the average particle size D50 of the secondary particles is 3.0 μm-20.0 μm, preferably 9.0 μm-11.0 μm; wherein D50 refers to the particle size corresponding to when the cumulative volume distribution percentage of the secondary particles of the positive electrode material of the nickel-hydrogen battery reaches more than 50%. The particle size in this article is tested using a Malvern 3000 laser particle size analyzer, with reference to the standard GB / T 19077-2016. Illustratively, the average particle size D50 of the secondary particles can be 3.0 μm, 4.0 μm, 5.0 μm, 6.0 μm, 7.0 μm, 8.0 μm, 9.0 μm, 10.0 μm, 11.0 μm, 12.0 μm, 13.0 μm, 14.0 μm, 15.0 μm, 16.0 μm, 17.0 μm, 18.0 μm, 19.0 μm, 20.0 μm or any value between 3.0 μm and 20.0 μm.

[0074] In some embodiments, the particle size distribution Span value of the secondary particles is 1.20-1.60, preferably 1.30-1.50; wherein, Span value = (D90-D10) / D50, D90 refers to the particle size corresponding to when the cumulative volume distribution percentage of the secondary particles of the positive electrode material of the nickel-hydrogen battery reaches more than 90%; D50 refers to the particle size corresponding to when the cumulative volume distribution percentage of the secondary particles of the positive electrode material of the nickel-hydrogen battery reaches more than 50%; D10 refers to the particle size corresponding to when the cumulative volume distribution percentage of the secondary particles of the positive electrode material of the nickel-hydrogen battery reaches more than 10%. Exemplarily, the particle size distribution Span value of the secondary particles can be 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50, 1.55, 1.60 or any value between 1.20-1.60. Under the particle size distribution range in this embodiment, the compressive resistance of the secondary particles of the positive electrode material of the nickel-hydrogen battery can be further improved, the structural stability is better, and it is conducive to improving the cycle performance.

[0075] In some embodiments, the sphericity of the secondary particles is 0.85-1.00, preferably 0.85-0.95; wherein the sphericity is calculated by using Avizo software to intelligently identify all secondary particles of the positive electrode material of the nickel-hydrogen battery in the 1000 times electron microscope image, and then taking the average value. Sphericity is an indicator of the roundness of the contour shape of the secondary particles. The closer the shape of the secondary particles is to a sphere, the closer the sphericity value is to 1, sphericity = (4π×area) / (perimeter×perimeter). Exemplarily, the sphericity of the secondary particles can be 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1.00 or any value between 0.85-1.00. Within the sphericity range of this embodiment, it is beneficial to maintain the structural stability of the secondary particles of the nickel-hydrogen battery positive electrode material, and can effectively improve the filling capacity of the positive electrode active material, thereby facilitating the improvement of performance such as cycle stability, discharge capacity and charge and discharge efficiency.

[0076] In some embodiments, the secondary particles have a BET surface area of ​​5 m 2 / g-10m 2 / g; wherein the specific surface area is determined according to GB / T 19587-2017 gas adsorption BET method for solid matter determination. Exemplarily, the specific surface area BET of the secondary particles can be 5m 2 / g, 5.5m 2 / g, 6m 2 / g, 6.5m 2 / g, 7m 2 / g, 7.5m 2 / g, 8m 2 / g, 8.5m 2 / g, 9m 2 / g, 9.5m 2 / g, 10m 2 / g or 5m 2 / g-10m 2 When the specific surface area of ​​the secondary particles is within the above suitable range, it is beneficial to reduce the side reaction between the positive electrode material and the electrolyte of the nickel-hydrogen battery.

[0077] In some embodiments, the tap density of the secondary particles is 2.10 g / cm 3 -2.40g / cm 3 , preferably 2.20g / cm 3 -2.40g / cm 3 ; The tap density TD is tested in accordance with GB / T 5162-2021 Determination of the tap density of metal powders. For example, the tap density TD of the secondary particles may be 2.10 g / cm 3 , 2.15g / cm 3 , 2.20g / cm 3 , 2.25g / cm 3 , 2.30g / cm 3 , 2.35g / cm 3 , 2.40g / cm 3 or 2.10g / cm 3 -2.40g / cm 3 When the tap density of the secondary particles is within the above-mentioned suitable range, it is beneficial to improve the overall stability of the positive electrode material of the nickel-hydrogen battery and the energy density of the nickel-hydrogen battery.

[0078] In some embodiments, the volume change rate of the secondary particles under a pressure of 5KN is ≤30%. Among them, the volume change rate is obtained by testing the same particle size sample after compaction under a pressure of 5KN. The specific test process is: 0.5g of sample is evenly installed in a cylindrical mold with a radius of 6.5mm, and the pressure is set to 5KN. After the pressure is reached, the pressure is maintained for 30S, and the sample is taken out for particle size testing. Volume change rate = (particle size before compression - particle size after compression) / particle size before compression × 100%, the particle size before compression and the particle size after compression are respectively represented by the D50 of the particles before compression and the particles after compression. The volume change rate of the secondary particles in the embodiment of the present application is small, indicating that the structural strength of the secondary particles is high, and it is not easy to produce cracks, breakage and other problems after being subjected to pressure, which is beneficial to improving the cycle performance of the battery.

[0079] In some embodiments, the chemical formula of the positive electrode material of the nickel-hydrogen battery is Ni x Co y Zn z(OH)2, where 0.8 ≤ x < 0.98, 0.01 < y ≤ 0.1, 0.01 < z ≤ 0.1, and x + y + z = 1. Exemplarily, in some embodiments, in the chemical general formula of the positive electrode material of the nickel-metal hydride battery, 0.85 ≤ x < 0.95, 0.02 < y ≤ 0.10, 0.02 < z ≤ 0.10, and x + y + z = 1; in some embodiments, the chemical formula of the positive electrode material of the nickel-metal hydride battery can be Ni 0.899 Co 0.054 Zn 0.047 (OH)2. In this embodiment, by further optimizing the doping element ratio of the positive electrode material of the nickel-metal hydride battery, it is beneficial to achieve better structural stability and longer cycle life, so as to improve the electrochemical performance such as the rate performance and cycle performance of the nickel-metal hydride battery.

[0080] Another embodiment of the present application provides a method for preparing a positive electrode material of a nickel-metal hydride battery, including the following steps: mixing a solvent, a precipitant, and a complexing agent to obtain a bottom solution; adding a metal salt solution containing nickel, cobalt, and zinc, a precipitant, and a complexing agent to the bottom solution for coprecipitation reaction, and controlling the solid content of the reaction system to be 150 g / L - 400 g / L by a concentrator until a reaction product is obtained; performing post-treatment on the reaction product to obtain the positive electrode material of the nickel-metal hydride battery. Wherein, the solid content refers to the total mass of solids in the reaction system divided by the total volume of the reaction system. Exemplarily, during the coprecipitation reaction, the solid content of the reaction system can be maintained at 150 g / L, 180 g / L, 200 g / L, 220 g / L, 250 g / L, 300 g / L, 320 g / L, 350 g / L, 380 g / L, 400 g / L or any value between 150 g / L - 400 g / L.

[0081] According to the preparation method provided by the embodiments of the present application, by selecting appropriate metal salt raw materials and controlling the steps and conditions of the coprecipitation reaction, the prepared positive electrode material of the nickel-metal hydride battery is a nickel-cobalt hydroxide doped with Co and Zn, and the cross-sectional porosity of the secondary particles of the positive electrode material of the nickel-metal hydride battery is ≤ 3.0%. Thus, by codoping Co and Zn in the nickel hydroxide and controlling the particle porosity of the nickel-cobalt hydroxide within the above appropriate range, it is beneficial to balance the cycle performance and rate performance.

[0082] In some embodiments, the metal salt includes at least one of sulfates, nitrates, acetates, and chlorides; in some embodiments, the total concentration of the metal salt solution is 100 g / L - 130 g / L; at this time, Co and Zn doping elements can be introduced through the metal salt, so as to further improve the performance of the positive electrode material of the nickel-metal hydride battery through Co and Zn codoping.

[0083] In some embodiments, the precipitant includes at least one of sodium hydroxide solution and potassium hydroxide solution; in some embodiments, the mass percentage concentration of the precipitant is 20%-35%; in some embodiments, the complexing agent includes at least one of ammonia water, ammonium bicarbonate solution, ammonium carbonate solution, EDTA solution, ethylenediamine solution, sodium citrate solution and ammonium sulfate solution; in some embodiments, the mass percentage concentration of the complexing agent is 10%-25%; in some embodiments, the solvent includes water. In the above embodiments, selecting appropriate precipitants, complexing agents and solvents can effectively regulate reaction conditions such as pH value, so as to facilitate the reaction process of preparing the positive electrode material of the nickel-hydrogen battery, thereby obtaining a positive electrode material of the nickel-hydrogen battery that meets the target requirements.

[0084] In some embodiments, the temperature of the base solution is 50°C-80°C; in some embodiments, the pH value of the base solution is 10.00-12.00; in some embodiments, the complexing agent is ammonia water, and the ammonia concentration of the base solution is 10g / L-20g / L.

[0085] In some embodiments, the feed rate of the metal salt solution is 5.5% / h-9.5% / h of the reaction container volume; in some embodiments, the feed rate of the precipitant of the coprecipitation reaction is 2.5% / h-5% / h of the reaction container volume; in some embodiments, the feed rate of the complexing agent of the coprecipitation reaction is 0.1% / h-2.5% / h of the reaction container volume.

[0086] In some embodiments, the stirring speed of the coprecipitation reaction is 400r / min-700r / min; in some embodiments, the reaction temperature of the coprecipitation reaction is the same as the temperature of the base solution and is 50°C-80°C; in some embodiments, the reaction pH value of the coprecipitation reaction is the same as the pH value of the base solution and is 10.00-12.00; in some embodiments, the complexing agent is ammonia water, and the ammonia concentration of the coprecipitation reaction is the same as the ammonia concentration of the base solution and is 10g / L-20g / L;

[0087] Since the nickel-hydrogen battery positive electrode material prepared in the embodiment of the present application contains cobalt and nickel doping elements, in order to ensure that the doping elements can play a better role in promoting the performance of the nickel-hydrogen battery positive electrode material as much as possible, it is necessary to strictly control the process conditions of the preparation process. Specifically, by controlling the process conditions of the preparation process within the above-mentioned appropriate range, it is beneficial to obtain a nickel-hydrogen battery positive electrode material that is effectively doped with cobalt and nickel elements and has a porosity that meets the requirements, so as to improve the electrochemical properties such as cycle performance and rate performance.

[0088] In some embodiments, the solid content of the reaction system of the coprecipitation reaction is 200 g / L-320 g / L, which is beneficial to further improve the electrochemical performance of the prepared Co, Zn co-doped nickel-hydrogen battery positive electrode material.

[0089] Another embodiment of the present application provides a nickel-hydrogen battery, including any of the above nickel-hydrogen battery positive electrode materials. Exemplarily, the positive electrode of the nickel-hydrogen battery in the embodiment of the present application can be prepared using the nickel-hydrogen battery positive electrode material in the above embodiment, and the positive electrode is assembled with the negative electrode, the separator, etc. to form a nickel-hydrogen battery. Based on the performance of the nickel-hydrogen battery positive electrode material, the nickel-hydrogen battery in the embodiment of the present application can take into account electrochemical properties such as cycle performance and rate performance.

[0090] Yet another embodiment of the present application provides an electrical device, including the above nickel-hydrogen battery.

[0091] The following examples describe the disclosure of the present application in more detail, and these examples are merely illustrative, as it will be apparent to those skilled in the art that various modifications and variations are made within the scope of the disclosure of the present application. Unless otherwise stated, all reagents and raw materials used in the following examples are commercially available or synthesized according to conventional methods, and the instruments used in the examples are commercially available.

[0092] Example 1

[0093] This embodiment provides a nickel-hydrogen battery positive electrode material, whose chemical formula is Ni 0.899 Co 0.054 Zn 0.047 (OH)2. The preparation method of the positive electrode material of the nickel-hydrogen battery includes:

[0094] Raw material preparation: Prepare appropriate amounts of 120g / L nickel sulfate solution, 120g / L cobalt sulfate solution, and 120g / L zinc sulfate solution. Mix appropriate amounts of nickel sulfate solution, cobalt sulfate solution, and zinc sulfate solution according to the molar ratio of Ni:Co:Zn=89.9:5.4:4.7 to prepare a metal salt solution with a concentration of 120g / L.

[0095] Co-precipitation reaction: pure water, sodium hydroxide solution (mass percentage concentration of 20.5%), and ammonia solution (mass percentage concentration of 10.5%) were added into the reactor as the base liquid, and nitrogen was introduced as the protective gas. The reaction temperature was 60°C, the stirring speed was 500r / min, and the pH value was adjusted to 12.00 and the free ammonia concentration was 16.68g / L. Metal salt solution (flow rate is 7.75% / h of the reactor volume), sodium hydroxide solution (flow rate is 2.5-3.5% / h of the reactor volume) and ammonia water (flow rate is 0.40-0.80% / h of the reactor volume) are introduced into the reactor for coprecipitation reaction. The reaction slurry reaches the upper limit of the reactor volume and begins to overflow. The stirring speed of the reaction process is maintained at 500r / min. The pH value of the reaction process is controlled to be 12.00 by fine-tuning the flow rate of sodium hydroxide solution and ammonia water. The free ammonia concentration is 16.68g / L and the solid content in the reactor is 320g / L. The reaction is continued until a reaction product with a particle size D50 that meets the requirements is obtained. The reaction product is filtered and washed, and the filter cake is dried, sieved, and demagnetized to obtain Ni 0.899 Co 0.054 Zn 0.047 (OH)2.

[0096] like Figure 1-2 As shown in the figure, the secondary particles of the positive electrode material of the nickel-hydrogen battery prepared in this embodiment are spherical or quasi-spherical, the cross-sectional pores are evenly distributed, the primary particles on the surface are coarse particles, the secondary particle size D50 is 10.137 μm, and the tap density is 2.32 g / cm 3 , with a specific surface area of ​​6.51m 2 / g.

[0097] The present embodiment also provides a method for preparing a nickel-hydrogen battery, comprising: (1) preparing a positive electrode sheet: mixing the prepared nickel-hydrogen battery positive electrode material with expanded graphite, carbonyl nickel powder and PTFE (polytetrafluoroethylene) in a mass ratio of 7:1:1:1 to form a slurry, applying the slurry on the nickel foam, pressing and forming the slurry with a roller press, drying and cutting the slurry, and finally welding the lugs and softening the slurry to obtain a positive electrode sheet; (2) preparing a negative electrode sheet: pressing and forming the AB5 alloy powder with a copper mesh as a carrier directly with a roller press, and then soaking the slurry in a 15% PTFE+CMC (carboxymethyl cellulose) aqueous solution and drying the slurry; (3) assembling a battery: winding the prepared positive electrode sheet, negative electrode sheet and diaphragm into a battery core and then loading the core into a battery steel shell, and then rolling the core, applying sealing oil, welding the battery cap and injecting electrolyte to seal the core in sequence, and finally chemically selecting the components to complete the battery assembly.

[0098] Electrochemical performance test: The electrochemical performance test of the nickel-hydrogen battery was carried out using a blue electric test system. The test voltage range is: 0.00-1.60V, 1C=200mAh / g. The preparation method of the nickel-hydrogen battery in the following examples and comparative examples is the same, and the electrochemical performance test method is also the same.

[0099] Example 2

[0100] The difference from Example 1 is that the solid content in the reactor of the coprecipitation reaction is controlled to 200 g / L by a concentrator.

[0101] like Figure 3-4 As shown in the figure, the secondary particles of the positive electrode material of the nickel-hydrogen battery prepared in this embodiment are spherical or quasi-spherical, the cross-sectional pores are evenly distributed, the primary particles on the surface are coarse particles, the secondary particle size D50 is 10.057 μm, and the tap density is 2.20 g / cm 3 , with a specific surface area of ​​7.07m 2 / g.

[0102] Example 3

[0103] The difference from Example 1 is that the stirring speed of the coprecipitation reaction is 450 r / min, and the solid content in the reactor of the coprecipitation reaction is controlled to be 260 g / L by a concentrator.

[0104] like Figure 5-6 As shown in the figure, the secondary particles of the positive electrode material of the nickel-hydrogen battery prepared in this embodiment are spherical or quasi-spherical, the cross-sectional pores are evenly distributed, the primary particles on the surface are coarse particles, the secondary particle size D50 is 10.492 μm, and the tap density is 2.26 g / cm 3 , with a specific surface area of ​​6.48m 2 / g.

[0105] Comparative Example 1

[0106] The difference from Example 1 is that the positive electrode material of the nickel-hydrogen battery does not contain doping elements, and the chemical formula is Ni 1.00 (OH)2.

[0107] like Figure 7 As shown, the secondary particles of the positive electrode material of the nickel-hydrogen battery prepared in this comparative example are spherical or quasi-spherical, the primary particles on the surface are flaky and uneven in thickness, the secondary particle size D50 is 10.020 μm, and the tap density is 1.90 g / cm 3 , with a specific surface area of ​​18.40m 2 / g.

[0108] Comparative Example 2

[0109] The difference from Example 1 is that the positive electrode material of the nickel-hydrogen battery contains only the doping element Co and no Zn, and its chemical formula is Ni 0.946 Co 0.054 (OH)2.

[0110] like Figure 8 As shown, the secondary particles of the positive electrode material of the nickel-hydrogen battery prepared in this comparative example are spherical or quasi-spherical, the primary particles on the surface are fine needle-shaped and uneven in thickness, the secondary particle size D50 is 9.954 μm, and the tap density is 1.83 g / cm 3 , with a specific surface area of ​​8.20m 2 / g.

[0111] Comparative Example 3

[0112] The difference from Example 1 is that the positive electrode material of the nickel-hydrogen battery contains only the doping element Zn and no Co, and its chemical formula is Ni 0.953 Zn 0.047 (OH)2.

[0113] like Fig. 9 As shown, the secondary particles of the positive electrode material of the nickel-hydrogen battery prepared in this comparative example are spherical or quasi-spherical, the primary particles on the surface are fine needle-shaped and uneven in thickness, the secondary particle size D50 is 10.413 μm, and the tap density is 1.78 g / cm 3 , with a specific surface area of ​​12.63m 2 / g.

[0114] Comparative Example 4

[0115] The difference from Example 1 is that the preparation method and conditions of the positive electrode material of the nickel-hydrogen battery are different. Specifically, the preparation method of the positive electrode material of the nickel-hydrogen battery includes:

[0116] Raw material preparation: Prepare appropriate amounts of 120g / L nickel sulfate solution, 120g / L cobalt sulfate solution, and 120g / L zinc sulfate solution. Mix appropriate amounts of nickel sulfate solution, cobalt sulfate solution, and zinc sulfate solution according to the molar ratio of Ni:Co:Zn=89.9:5.4:4.7 to prepare a metal salt solution with a concentration of 120g / L.

[0117] Co-precipitation reaction: pure water, sodium hydroxide solution (mass percentage concentration of 20.5%), and ammonia solution (mass percentage concentration of 10.5%) were added into the reactor as the base liquid, and nitrogen was introduced as the protective gas. The reaction temperature was 60°C, the stirring speed was 500r / min, and the pH value was adjusted to 10.60 and the free ammonia concentration was 16.68g / L. A metal salt solution (with a flow rate of 7.75% / h of the reactor volume), a sodium hydroxide solution (with a flow rate of 2.5-3.5% / h of the reactor volume) and an ammonia solution (with a flow rate of 0.40-0.80% / h of the reactor volume) were introduced into the reactor to carry out a coprecipitation reaction. During the reaction, an appropriate amount of seed crystals (the seed crystals were particles with the same chemical composition and a D50 of 2.0-3.0 μm) were added in batches. When D50 was less than 9.5 μm, an appropriate amount of seed crystals was added to maintain a D50 growth rate of 0.1-0.7 μm / hour. The reaction slurry reached the upper limit of the reactor volume and began to overflow. The stirring speed during the reaction process was maintained at 500 r / min. The pH value of the reaction process was controlled to be 10.60 by fine-tuning the flow rates of the sodium hydroxide solution and the ammonia solution. The free ammonia concentration was 16.68 g / L and the solid content in the reactor was 130 g / L. The particle size of the overflow material is D50 = 9.5-10.5 μm (add appropriate amount of seed crystals in batches to control D50 within the required range), and the overflow material is taken as the reaction product. The reaction product is filtered and washed, and the filter cake is dried, sieved, and demagnetized to obtain Ni 0.899 Co 0.054 Zn 0.047 (OH)2.

[0118] like Fig.10 As shown in the figure, the secondary particles of the positive electrode material of the nickel-hydrogen battery prepared in this embodiment are spherical or quasi-spherical, the primary particles on the surface are strip-shaped, the secondary particle size D50 is 9.854 μm, and the tap density is 2.04 g / cm 3 , with a specific surface area of ​​11.17m 2 / g.

[0119] Comparative Example 5

[0120] The difference from Example 1 is that the preparation method and conditions of the positive electrode material of the nickel-hydrogen battery are different. Specifically, the preparation method of the positive electrode material of the nickel-hydrogen battery includes:

[0121] Raw material preparation: Prepare appropriate amounts of 120g / L nickel sulfate solution, 120g / L cobalt sulfate solution, and 120g / L zinc sulfate solution. Mix appropriate amounts of nickel sulfate solution, cobalt sulfate solution, and zinc sulfate solution according to the molar ratio of Ni:Co:Zn=89.9:5.4:4.7 to prepare a metal salt solution with a concentration of 120g / L.

[0122] Co-precipitation reaction: pure water, sodium hydroxide solution (mass percentage concentration of 20.5%), and ammonia solution (mass percentage concentration of 10.5%) were added into the reactor as the base liquid, and nitrogen was introduced as the protective gas. The reaction temperature was 75°C, the stirring speed was 500r / min, and the pH value was adjusted to 10.30 and the free ammonia concentration was 7.20g / L. A metal salt solution (with a flow rate of 7.75% / h of the reactor volume), a sodium hydroxide solution (with a flow rate of 2.5-3.5% / h of the reactor volume) and an ammonia solution (with a flow rate of 0.40-0.80% / h of the reactor volume) were introduced into the reactor to carry out a coprecipitation reaction. During the reaction, an appropriate amount of seed crystals (the seed crystals were particles with the same chemical composition and a D50 of 2.0-3.0 μm) were added in batches. When D50 was less than 9.5 μm, an appropriate amount of seed crystals was added to maintain a D50 growth rate of 0.1-0.7 μm / hour. The reaction slurry reached the upper limit of the reactor volume and began to overflow. The stirring speed during the reaction process was maintained at 500 r / min. The pH value of the reaction process was controlled to be 10.30 by fine-tuning the flow rates of the sodium hydroxide solution and the ammonia solution, the free ammonia concentration was 7.20 g / L, and the solid content in the reactor was 130 g / L. The particle size of the overflow material is D50 = 9.5-10.5 μm (add appropriate amount of seed crystals in batches to control D50 within the required range), and the overflow material is taken as the reaction product. The reaction product is filtered and washed, and the filter cake is dried, sieved, and demagnetized to obtain Ni 0.899 C o 0.054 Zn 0.047 (OH)2.

[0123] like Fig.11 As shown in the figure, the cross-sectional pores of the secondary particles of the positive electrode material of the nickel-hydrogen battery prepared in this embodiment are rich. The particle size D50 of the secondary particles is 10.211 μm, and the tap density is 1.81 g / cm 3 , the specific surface area is 23.19m 2 / g.

[0124] Table 1. Physical and chemical properties of the positive electrode materials for nickel-hydrogen batteries of various embodiments and comparative examples

[0125]

[0126] Table 2. Morphological characteristics of the positive electrode materials of nickel-hydrogen batteries in various embodiments and comparative examples

[0127]

[0128]

[0129] Table 3. Electrochemical properties of the positive electrode materials for nickel-hydrogen batteries of various embodiments and comparative examples

[0130]

[0131] According to Table 1-Table 3 and Figures 1 to 8 It can be seen that Comparative Examples 1 to 3 do not use the cobalt and zinc co-doping method to prepare the positive electrode material of the nickel-hydrogen battery, and cannot take into account both the cycle capacity retention rate and the high-temperature cycle performance. Specifically, compared with Examples 1 to 3, the positive electrode materials of Comparative Examples 1 to 3 are not co-doped with cobalt and zinc elements, and the secondary particle density is low, and the corresponding cycle capacity retention rate and high-temperature cyclability are low; while the positive electrode materials of the nickel-hydrogen battery of Examples 1 to 3 have a dense structure and a small pore volume ratio (from Figure 2 It can be seen from the figure that the pore distribution does not aggregate and the overall distribution is uniform), which is conducive to structural stability when subjected to stress, and Zn will enhance the Ni-O bond of the nickel hydroxide lattice, enhance the stability of the internal structure, and the co-doping of Co and Zn can increase the oxygen evolution overpotential, inhibit the occurrence of oxygen evolution side reactions, and significantly improve the cycle capacity retention rate and high-temperature cycle performance. In addition, the positive electrode material of Comparative Example 2 is doped with cobalt, and its high-temperature cycle performance is better than that of Comparative Examples 1 and 3, further indicating that doping with cobalt is conducive to improving the cycle performance; the positive electrode material of Comparative Example 3 is doped with zinc, and its capacity retention rate is better than that of Comparative Examples 1 and 2, further indicating that doping with zinc is conducive to improving the capacity retention rate.

[0132] Moreover, Examples 1 to 3 all adopt the method of co-doping Co and Zn elements to prepare the positive electrode material of nickel-hydrogen battery, which has differences in structure and physicochemical properties, and there are differences in capacity retention rate and cycle performance at high temperature. For example, compared with Example 2, Example 1 is more compact in morphology, which improves the cycle performance at high temperature and increases the capacity retention rate. The above differences occur because the structure is dense and the crystallinity is good, the phase stability is high, the electrode deformation is reduced during overcharging, and the sphericity is excellent, which is conducive to the dense filling of secondary particles. It can be seen that the Co and Zn co-doped nickel-hydrogen battery positive electrode material with special composition and physicochemical properties prepared based on the embodiments of the present application has good electrochemical properties such as cycle performance and rate performance.

[0133] The various technical features described above can be combined arbitrarily. Although all possible combinations of these technical features are not described, any combination of these technical features should be considered to be covered by this specification as long as there is no contradiction in such combination.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application 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 by 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 application.

Claims

1. A nickel-hydrogen battery positive electrode material, characterized in that: The positive electrode material of the nickel-hydrogen battery is a nickel hydroxide doped with cobalt and zinc elements. The positive electrode material of the nickel-hydrogen battery includes secondary particles composed of a plurality of primary particles. The cross-sectional porosity of the secondary particles is ≤3.0%.

2. The positive electrode material for nickel-hydrogen batteries according to claim 1, characterized in that: The cross-sectional porosity of the secondary particles is 0.1%-3.0%, preferably 0.1%-1.5%.

3. The positive electrode material for nickel-hydrogen batteries according to claim 1, characterized in that: The nickel-hydrogen battery positive electrode material meets at least one of the following conditions: a. The primary particles on the surface of the secondary particles are spindle-shaped or granular; b. The aspect ratio of the primary particles on the surface of the secondary particles is (1.5-6):1; c. The length of the primary particles on the surface of the secondary particles is 200nm-800nm, preferably 400nm-700nm; d. The width of the primary particles on the surface of the secondary particles is 100nm-400nm, preferably 100nm-300nm; e. The primary particles inside the secondary particles are arranged radially along the radial direction of the secondary particles.

4. The positive electrode material for nickel-hydrogen batteries according to claim 1, characterized in that: The nickel-hydrogen battery positive electrode material meets at least one of the following conditions: f. The average particle size D50 of the secondary particles is 3.0 μm-20.0 μm, preferably 9.0 μm-11.0 μm; h. The particle size distribution Span value of the secondary particles is 1.20-1.60, preferably 1.30-1.50; i. The sphericity of the secondary particles is 0.85-1.00, preferably 0.85-0.95; j. The specific surface area of ​​the secondary particles is 5m 2 / g-10m 2 / g; k. The tap density of the secondary particles is 2.10 g / cm 3 -2.40g / cm 3 , preferably 2.20g / cm 3 -2.40g / cm 3 ; 1. The volume change rate of the secondary particles under a pressure of 500N is ≤30%; m. The chemical formula of the positive electrode material of the nickel-hydrogen battery is Ni x Co y Zn z (OH)2, where 0.8≤x<0.98, 0.01 <y≤0.1,0.01<z≤0.1,x+y+z=1; n. Divide the cross section of the secondary particles into several equal parts according to area, and the cross-sectional porosity of each cross section is ≤3.0%, preferably ≤1.5%.

5. A method for preparing a positive electrode material for a nickel-hydrogen battery, characterized in that: The following steps are involved: Mixing a solvent, a precipitant and a complexing agent to obtain a base solution; Adding a metal salt solution containing nickel, cobalt and zinc, a precipitant and a complexing agent to the base liquid to carry out a coprecipitation reaction, maintaining the solid content of the reaction system at 150 g / L-400 g / L until a reaction product is obtained; The reaction product is post-processed to obtain a positive electrode material for a nickel-hydrogen battery.

6. The method for preparing the positive electrode material of a nickel-hydrogen battery according to claim 5, characterized in that: The preparation method satisfies at least one of the following conditions ①-⑦: ①, the metal salt includes at least one of sulfate, nitrate, acetate and chloride; ②, the total concentration of the metal salt solution is 100g / L-130g / L; ③. The precipitant includes at least one of a sodium hydroxide solution and a potassium hydroxide solution; ④. The mass percentage concentration of the precipitant is 20%-35%; ⑤. The complexing agent includes at least one of ammonia water, ammonium bicarbonate solution, ammonium carbonate solution, EDTA solution, ethylenediamine solution, sodium citrate solution and ammonium sulfate solution; ⑥, the mass percentage concentration of the complexing agent is 10%-25%; ⑦. The solvent includes water.

7. The method for preparing the positive electrode material of a nickel-hydrogen battery according to claim 5, characterized in that: The temperature of the base liquid is 50°C-80°C; and / or The pH value of the base liquid is 10.00-12.00; and / or The complexing agent is ammonia water, and the ammonia concentration of the base solution is 10g / L-20g / L.

8. The method for preparing the positive electrode material of a nickel-hydrogen battery according to claim 5, characterized in that: The preparation method satisfies at least one of the following conditions (1)-(8): (1) The feeding rate of the metal salt solution is 5.5% / h-9.5% / h of the volume of the reaction container; (2) The feed rate of the precipitant in the coprecipitation reaction is 2.5% / h-5% / h of the volume of the reaction container; (3) The feeding rate of the complexing agent in the coprecipitation reaction is 0.1% / h-2.5% / h of the volume of the reaction container; (4) The stirring speed of the coprecipitation reaction is 400r / min-700r / min; (5) The reaction temperature of the coprecipitation reaction is the same as the temperature of the base solution and is 50° C.-80° C.; (6) The reaction pH value of the coprecipitation reaction is the same as the pH value of the base solution and is 10.00-12.00; (7) The complexing agent is ammonia water, and the ammonia concentration of the coprecipitation reaction is the same as the ammonia concentration of the base solution and is 10g / L-20g / L; (8) The solid content of the reaction system of the coprecipitation reaction is 200 g / L-320 g / L.

9. A nickel-hydrogen battery, characterized in that: The nickel-hydrogen battery positive electrode material comprises any one of claims 1-8.

10. An electrical equipment, characterized in that: Including the nickel-hydrogen battery as claimed in claim 9.

Images