CN-116111079-B - Nickel cobalt manganese hydroxide precursor with radial porous structure and preparation method thereof

CN116111079BCN 116111079 BCN116111079 BCN 116111079BCN-116111079-B

Abstract

The invention discloses a nickel cobalt manganese hydroxide precursor with a radial porous structure and a preparation method thereof, and belongs to the technical field of lithium ion battery materials, wherein the chemical formula of the nickel cobalt manganese hydroxide precursor with the radial porous structure is Ni x Co y Mn 1‑x‑y (OH) 2 , x is more than or equal to 0.5 and less than or equal to 1, and y is more than or equal to 0 and less than or equal to 0.4; the nickel cobalt manganese hydroxide precursor has thin primary crystal grains and the primary particles are mutually staggered and associated to form radial secondary particles with loose and porous interiors, so that the secondary spherical particles have relatively high specific surface area, more transmission channels can be provided for lithium ions in the sintering process with a lithium source, meanwhile, the resistance of lithium ion intercalation and deintercalation is reduced in the charging and discharging process, the transmission distance of the lithium ions is shortened, and the transmission rate is improved.

Inventors

LUO RONGJIE
LIU GENGHAO
Deng Ruichao
RUAN DINGSHAN
LI CHANGDONG
Xu Xueliu

Assignees

广东邦普循环科技有限公司
湖南邦普循环科技有限公司

Dates

Publication Date: 20260508
Application Date: 20230206

Claims (9)

1. The nickel cobalt manganese hydroxide precursor with the radial porous structure is characterized in that the chemical formula of the nickel cobalt manganese hydroxide precursor is Ni x Co y Mn 1-x-y (OH) 2 , wherein x is more than or equal to 0.5 and less than or equal to 1, and y is more than or equal to 0 and less than or equal to 0.4; the nickel cobalt manganese hydroxide precursor has thin primary grains and the primary grains are mutually staggered and associated to form radial secondary grains with loose and porous inside, the specific surface area is 20-30 m 2 /g, The preparation method of the nickel cobalt manganese hydroxide precursor with the radial porous structure comprises the following steps: (1) Preparing nickel salt, cobalt salt and manganese salt into metal salt solution by using water according to the mole ratio of nickel, cobalt and manganese elements in the nickel cobalt manganese hydroxide precursor; (2) Under the protective atmosphere, adding a sodium hydroxide solution, an ammonia water solution and water into a reaction kettle to prepare a reaction base solution with the pH value of 9.5-11.9 and the ammonia concentration of 0.5-10.0 g/L, introducing a metal salt solution, the sodium hydroxide solution and the ammonia water solution into the reaction kettle to perform coprecipitation reaction, adjusting the pH value to 10.7-11.6 when the particle size grows to 2.5-4.0 mu m, continuously reacting until the particle size is stabilized to 3.5-5.0 mu m, collecting materials, centrifuging and dehydrating to obtain a seed crystal filter cake; (3) Under the protective atmosphere, adding a sodium hydroxide solution, an ammonia water solution and water into a reaction kettle to prepare a reaction base solution with the pH value of 9.5-11.9 and the ammonia concentration of 0.5-10.0 g/L, adding a seed crystal filter cake into the reaction kettle, then introducing a metal salt solution, the sodium hydroxide solution and the ammonia water solution, opening an overflow valve to react, closing the overflow valve when the granularity grows to 5.0-7.0 mu m, starting a concentrator, reacting until the granularity grows to 7.5-9 mu m, adjusting the flow of the metal salt solution, collecting materials when the granularity grows to 9.2-15.0 mu m, aging, washing, drying and sieving to obtain the nickel cobalt manganese hydroxide precursor with the radial porous structure.
2. The nickel cobalt manganese hydroxide precursor with the radial porous structure according to claim 1, wherein the nickel cobalt manganese hydroxide precursor has a microscopic morphology of spheroidal particles, a tap density of 1.5-2.5 g/cm 3 and a particle size distribution diameter distance of less than or equal to 1.0.
3. The nickel cobalt manganese hydroxide precursor with the radial porous structure according to claim 2, wherein the nickel cobalt manganese hydroxide precursor has a microscopic morphology of spheroidal particles, a tap density of 1.6-2 g/cm 3 and a particle size distribution diameter distance of less than or equal to 0.7.
4. The nickel cobalt manganese hydroxide precursor of a radial porous structure according to claim 1, wherein the nickel salt comprises at least one of nickel sulfate, nickel nitrate, and nickel chloride, and/or The cobalt salt comprises at least one of cobalt sulfate, cobalt nitrate and cobalt chloride, and/or The manganese salt includes at least one of manganese sulfate, manganese nitrate, and manganese chloride.
5. The radially porous nickel cobalt manganese hydroxide precursor according to claim 1, wherein the total metal ion concentration of the metal salt solution is 0.5 to 4mol/L.
6. The radially porous nickel cobalt manganese hydroxide precursor according to claim 1, wherein the molar concentration of the sodium hydroxide solution is 0.5 to 14mol/L, and the molar concentration of the aqueous ammonia solution is 0.5 to 14mol/L.
7. The nickel cobalt manganese hydroxide precursor with the radial porous structure according to claim 1, wherein in the step (2), the flow rate of the metal salt solution is 20-60 l/h, the flow rate of the sodium hydroxide solution is 8-25 l/h, and the flow rate of the ammonia solution is 0.5-4 l/h.
8. The nickel cobalt manganese hydroxide precursor with the radial porous structure according to claim 1, wherein the flow rate of the metal salt solution in the step (3) is 20-60 l/h, the flow rate of the sodium hydroxide solution is 4-15 l/h, and the flow rate of the ammonia solution is 0-0.8 l/h.
9. The nickel cobalt manganese hydroxide precursor with a radial porous structure according to claim 1, wherein the flow rate of the metal salt solution in the step (3) is adjusted to be 40-50 l/h.

Description

Nickel cobalt manganese hydroxide precursor with radial porous structure and preparation method thereof Technical Field The invention relates to the technical field of lithium ion battery materials, in particular to a nickel cobalt manganese hydroxide precursor with a radial porous structure and a preparation method thereof. Background The lithium ion battery is widely applied to the fields of portable electronic equipment, energy storage, electric automobiles, aerospace, and the like by virtue of the advantages of high working voltage, high energy density, low self-discharge rate, long cycle life, good safety performance, no memory effect and the like. The excellent electrochemical performance of the lithium ion battery is greatly dependent on the performance of the positive electrode material, and the lithium ion battery is most prominent among various types of positive electrode materials. At present, the preparation of a ternary positive electrode material mainly comprises the synthesis of a ternary precursor and the synthesis of a ternary oxide, firstly, synthesizing the ternary precursor, then mixing and sintering the ternary precursor and a lithium source to prepare the ternary oxide positive electrode material, wherein the physicochemical property of the prepared ternary precursor directly influences the core electrochemical property of the ternary positive electrode material in the process, currently, the main method for preparing the ternary precursor (nickel cobalt manganese hydroxide) is a coprecipitation method, namely, a nickel cobalt manganese metal salt solution is subjected to the coaction with a complexing agent and a precipitator under certain conditions to generate coprecipitation reaction to prepare spherical-like secondary particles, and finally the nickel cobalt manganese hydroxide precursor is obtained after the procedures of aging, washing, drying, sieving and the like. The size, morphology, internal structure and the like of the precursor have direct influence on the performance of the ternary positive electrode material of the lithium ion battery. The ternary positive electrode material prepared by adopting the internal loose porous whisker precursor can well improve the electrochemical properties such as specific capacity, rate capability and the like of the material. The invention patent publication numbers CN111717941A and CN114105222A respectively disclose a nickel cobalt manganese hydroxide of needle whisker and a preparation method thereof, and a nickel cobalt manganese hydroxide with a porous structure and a preparation method thereof, wherein the thickness of the whisker of the particle is controlled by continuously adjusting the oxygen content in a kettle, so that the prepared product is needle, has a loose porous internal structure and a higher specific surface area. The methods described in these patents require an increase in oxygen consumption on the one hand and complexity in process control on the other hand and the degree of oxidation of the material is difficult to control. The invention patent with publication number CN115012036A discloses a nickel cobalt manganese hydroxide with small grain diameter of fine whisker and a preparation method thereof, the invention mainly prepares the nickel cobalt manganese hydroxide with small grain diameter of slender whisker by controlling ammonia concentration, feeding amount and rotating speed in a kettle, but the ammonia concentration is controlled to be 1-6 mol/L, the required ammonia concentration is higher, and the consumption of ammonia can be increased to a certain extent. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a nickel cobalt manganese hydroxide precursor with a radial porous structure and a preparation method thereof, wherein primary grains of the nickel cobalt manganese hydroxide precursor are thin and are mutually staggered and associated to form radial secondary particles with loose and porous inside, an ion transmission channel is ensured, the contact area of electrolyte is increased, the problem of material cracking in the charging and discharging process is solved, and the improvement of electrochemical performance is facilitated. In order to achieve the above object, in a first aspect of the present invention, there is provided a nickel cobalt manganese hydroxide precursor having a radial porous structure, the nickel cobalt manganese hydroxide precursor having a chemical formula of Ni xCoyMn1-x-y(OH)2, wherein 0.5≤x≤1, and 0≤y≤0.4; The primary grains of the nickel cobalt manganese hydroxide precursor are thin, and primary particles are mutually staggered and associated to form radial secondary particles with loose and porous interiors. As a preferred embodiment of the invention, the nickel cobalt manganese hydroxide precursor has a microscopic morphology of sphere-like particles, a specific surface area of 8.0-35 m 2/g, a tap density of 1.5-2.5 g/cm 3 and