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CN-121990619-A - High-nickel precursor material for lithium ion battery and preparation method thereof

CN121990619ACN 121990619 ACN121990619 ACN 121990619ACN-121990619-A

Abstract

The invention relates to the technical field of high-nickel precursor materials, and relates to a high-nickel precursor material for a lithium ion battery and a preparation method thereof. The method comprises the steps of (1) preparing a mixed salt solution by using soluble nickel salt and soluble cobalt salt, (2) introducing the mixed salt solution, a doping additive, a precipitant and a complexing agent into a reaction kettle under a protective atmosphere, performing constant-temperature coprecipitation, stopping introducing the mixed salt solution and the doping additive after reaching a preset granularity, introducing a coating additive, reacting to form a coating layer, obtaining qualified slurry after finishing, and obtaining the spherical high-nickel precursor material which can bear high pressure, is not easy to collapse and is not easy to crack after post treatment. The primary particles of the precursor can be thinned through the tungsten doping agent, a more loose and porous precursor can be formed by combining the double complexing agents, and meanwhile, the aluminum coating layer and the loose and porous interior jointly act to enable the precursor to have better pressure resistance and cracking resistance.

Inventors

  • SHEN JIACHENG
  • JI TONGZONG
  • ZHENG BIN
  • ZHANG LIMING
  • HUANG YAFAN
  • YANG FAN
  • WU YOUZHI
  • XUN RUIZHI
  • ZHOU ZIGUI

Assignees

  • 浙江海创锂电科技有限公司

Dates

Publication Date
20260508
Application Date
20251231

Claims (10)

  1. 1. The preparation method of the high-nickel precursor material for the lithium ion battery is characterized by comprising the following steps of: (1) Preparing a mixed salt solution by adopting soluble nickel salt and soluble cobalt salt; (2) Under the protective atmosphere, introducing a mixed salt solution, a tungsten-containing doping additive, a precipitant and a complexing agent into a reaction kettle, continuously increasing the solid content in the reaction kettle, performing constant-temperature coprecipitation at a certain stirring rate, stopping introducing the mixed salt solution and the doping additive after reaching a preset granularity, introducing an aluminum-containing coating additive, and reacting to form a coating layer, thereby obtaining qualified slurry, wherein the complexing agent is a double complexing agent of ammonium sulfate and EDTA or soluble salts thereof; (3) And (3) post-treating the qualified slurry obtained by the reaction to obtain the spherical high-nickel precursor material.
  2. 2. The method for preparing the high-nickel precursor material for the lithium ion battery according to claim 1, wherein in the step (1), the molar ratio of nickel ions to cobalt ions in the mixed salt solution=x:y, x+y= 1,0.85 < x <1,0< y < 0.15, and the concentration of metal ions in the mixed salt solution is 0.5-2.5 mol/L.
  3. 3. The method for preparing a high nickel precursor material for a lithium ion battery according to claim 1, wherein in the step (2), the precipitant is sodium hydroxide solution with a concentration of 2-10mol/L.
  4. 4. The preparation method of the high-nickel precursor material for the lithium ion battery, which is disclosed in claim 1, is characterized in that in the step (2), the complexing agent is an ammonium sulfate solution and an EDTA disodium salt solution, the concentration of the ammonium sulfate solution is 0.1-1.5 mol/L, and the concentration of the EDTA disodium salt solution is 0.01-0.3 mol/L.
  5. 5. The method for preparing a high-nickel precursor material for a lithium ion battery according to claim 1, wherein in the step (2), the tungsten-containing doping additive is a sodium tungstate solution with a concentration of 0.1-2.5 mol/L.
  6. 6. The method for preparing a high-nickel precursor material for a lithium ion battery according to claim 1, wherein in the step (2), the aluminum-containing coating additive is an aluminum sulfate solution with a concentration of 0.1-1.5 mol/L.
  7. 7. The method for preparing a high nickel precursor material for a lithium ion battery according to claim 1, wherein in the step (2), constant-temperature coprecipitation is performed at a temperature ranging from 25 ℃ to 75 ℃.
  8. 8. The method for preparing a high-nickel precursor material for a lithium ion battery according to claim 1, wherein in the step (2), the solid content in the reaction is 80-900 g/L.
  9. 9. The method for preparing a high-nickel precursor material for a lithium ion battery according to claim 1, wherein in the step (2), the stirring speed of the reactor in the reaction is 100-450 rpm.
  10. 10. A high nickel precursor material for lithium ion batteries prepared by the preparation method according to any one of claims 1 to 9.

Description

High-nickel precursor material for lithium ion battery and preparation method thereof Technical Field The invention relates to the technical field of lithium ion power batteries for new energy automobiles, in particular to a high-nickel precursor material for a lithium ion battery and a preparation method thereof. Background With the continuous increase of the demand of the new energy automobile industry for high-energy density power batteries, the high-nickel positive electrode material (nickel content is more than or equal to 80 mol%) stands out by virtue of the remarkable energy density advantage. The material not only has specific capacity of more than 200mAh/g (which is improved by 15% -20% compared with the conventional ternary material), but also can effectively improve the energy density of a battery unit to more than 300Wh/kg, so that the material is recognized as a main flow technical route of a next-generation power battery by the industry. However, the conventional high-nickel precursor has the defects that (1) a compact structure causes a long lithium ion diffusion path and affects the rate performance, and (2) the high-nickel material is easy to generate phase change and microcrack in the charge and discharge process, so that the crystal structure collapses. The precursor is used as a key raw material of the positive electrode material, and the performance index of the precursor directly determines the core characteristics of the final positive electrode material. Therefore, the loose modification of the precursor structure is an effective strategy, and the optimization of the precursor loose structure on the performance of the positive electrode material is mainly characterized in that the loose structure can shorten the lithium ion diffusion path, reduce the internal resistance, remarkably improve the battery multiplying power performance ‌, the loose porous property can promote the permeation of electrolyte and improve the electrode-electrolyte interface reaction dynamics, and the volume expansion stress in the charging and discharging process can be relieved by regulating the loose degree, so that the cycle life ‌ ‌ is effectively prolonged. However, although the loose structure of the precursor can play a certain role and advantage, the loose structure of the precursor presents a greater challenge to the structural stability of the material, namely, the loosening of the structure seriously weakens the mechanical strength and structural integrity of the particles, so that collapse, cracking and other phenomena of the precursor material occur in the subsequent preparation process and application process of the precursor material, particularly the process involving high pressure, and the disadvantage of further structural stability is reflected. Based on the defect that the structure of the traditional high-nickel precursor material is easy to collapse and crack, the invention explores a method which can be applied on a large scale to prepare the high-nickel precursor material which can bear high pressure, is not easy to collapse and crack, and has the characteristics of high structural stability and the like. Disclosure of Invention At present, the traditional high-nickel precursor has the problems of compact structure, easy structural collapse and easy cracking during application, and the like. Aiming at the problems, the invention explores a method capable of being applied on a large scale, prepares a high-nickel precursor which can bear high pressure and is not easy to collapse and crack, and solves the problem of structural stability of the precursor that the precursor is easy to cause structural collapse and crack. In order to achieve the above object, the present invention provides the following technical solutions: The preparation method of the high-nickel precursor material for the lithium ion battery comprises the following steps: (1) Preparing a mixed salt solution by adopting soluble nickel salt and soluble cobalt salt; (2) Under the protective atmosphere, introducing a mixed salt solution, a tungsten-containing doping additive, a precipitant and a complexing agent into a reaction kettle, continuously increasing the solid content in the reaction kettle, performing constant-temperature coprecipitation at a certain stirring rate, stopping introducing the mixed salt solution and the doping additive after reaching a preset granularity, introducing an aluminum-containing coating additive, and reacting to form a coating layer, wherein the coating layer is reacted to obtain qualified slurry, and the complexing agent is a double complexing agent of ammonium sulfate and EDTA or soluble salt thereof; (3) And (3) post-treating the qualified slurry obtained by the reaction to obtain the spherical high-nickel precursor material which can bear high pressure, is not easy to collapse and is not easy to crack. The technical scheme includes that a mixed salt solution is prepared by adopting solubl