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Gradient doping and surface modification of cathode materials for single crystal high nickel lithium ion batteries

A technology for ion batteries and positive electrode materials, applied in battery electrodes, positive electrodes, secondary batteries, etc., can solve the problems of deteriorating battery cycle life and reversible capacity, intensifying side reactions between single crystal materials and electrolytes, and affecting battery life, etc. , to achieve excellent high-temperature cycle stability, improve rate performance and cycle stability, and stabilize structural collapse

Active Publication Date: 2022-07-12
SOUTH CHINA UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] (1) Traditional ternary materials are secondary spherical particles formed by the accumulation of primary particles. The stress generated by the multi-phase transformation process during the cycle will cause microcracks to appear in the spherical particles at the grain boundaries of the primary particles. The cracks further expand in the cycle and seriously deteriorate the cycle life and reversible capacity of the battery
[0006] (2) The side reaction between the single crystal material and the electrolyte is intensified under high temperature working conditions, further deteriorating the surface condition
Under high temperature conditions, the side reaction between the material and the electrolyte will be intensified, and the corrosion of the material along the defect by the electrolyte will be further aggravated, which seriously affects the service life of the battery during normal use, and even endangers the thermal safety of the battery.

Method used

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  • Gradient doping and surface modification of cathode materials for single crystal high nickel lithium ion batteries
  • Gradient doping and surface modification of cathode materials for single crystal high nickel lithium ion batteries
  • Gradient doping and surface modification of cathode materials for single crystal high nickel lithium ion batteries

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Embodiment 1

[0045] In order to further improve the high-temperature performance of the single-crystal high-nickel ternary positive electrode material and make it suitable for high-temperature working conditions, the present invention proposes a single-crystal high-nickel alloy with in-situ bulk doping of X elements and in-situ gradient doping of Y elements. Ternary material, based on the stable layered rock salt structure, builds a doped layer with stable high temperature conditions near the surface of the material, improves the ion diffusion rate of the material at high temperature, and effectively inhibits the surface of the high-nickel ternary material. Structural transformation, inhibits the generation of microcracks, and effectively relieves the surface Ni at high temperature 4+ The reactivity with the electrolyte enables it to be effectively applied in the high temperature range, simultaneously improving the rate performance and cycle stability of the battery.

[0046] The present i...

Embodiment 2

[0059] The gradient doping and surface modification method for effectively improving the high temperature performance of the cathode material of the single crystal high nickel lithium ion battery provided by the embodiment of the present invention includes the following steps:

[0060] 1) According to the chemical expression, it is LiNi 0.89 Co 0.08 Mn 0.02 Mg 0.004 Sb 0.006 O 2 In the stoichiometric ratio of Ni, Co, Mn and Mg elements, weigh 15.771kg of nickel sulfate hexahydrate, 0.836kg of cobalt sulfate, 0.204kg of manganese sulfate and 0.032kg of magnesium sulfate and dissolved in 20L of deionized water together to configure solution A; Meanwhile, according to the stoichiometric ratio, weigh 0.092 kg of antimony chloride, dissolve it in 0.2 L of deionized water, and configure solution B.

[0061] 2) dissolving sodium hydroxide and ammonia water in deionized water together, and configuring into a mixed alkali solution with sodium hydroxide concentration of 8mol / L and ...

Embodiment 3

[0066] The gradient doping and surface modification method for effectively improving the high-temperature performance of the cathode material of a single-crystal high-nickel lithium-ion battery provided by the embodiment of the present invention includes the following steps:

[0067] 1) According to the chemical expression, it is LiNi 0.89 Co 0.08 Mn 0.07 Ti 0.003 Nb 0.003 O 2 In the stoichiometric ratio of Ni, Co, Mn and Ti elements, weigh 16.261kg of nickel nitrate, 1.464kg of cobalt nitrate, 1.253kg of manganese nitrate and 0.057kg of titanium chloride and dissolve them in 20L of deionized water together to configure solution A; According to the stoichiometric ratio, 0.161 kg of niobium oxalate was weighed and dissolved in 0.2 L of deionized water to prepare solution B.

[0068] 2) dissolving sodium hydroxide and ammonia water in deionized water together, and configuring into a mixed alkali solution with a sodium hydroxide concentration of 3 mol / L and an ammonia water ...

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Abstract

The invention belongs to the technical field of positive electrode materials for lithium ion batteries, and discloses a method for gradient doping and surface modification of positive electrode materials for single crystal high-nickel lithium ion batteries. Metal salts are dissolved in deionized water together to configure solution A; soluble Y metal salts are weighed and dissolved in deionized water according to the stoichiometric ratio to configure solution B; soluble alkali and ammonia water are jointly dissolved in deionized water; solution A is , mixed lye and solution B were pumped into the reactor, left to stand for aging, the precipitate was filtered, washed, and dried to obtain single crystal Ni a Co b Mn c X x Y y (OH) 2 Precursor; single crystal Ni a Co b Mn c X x Y y (OH) 2 The precursor is mixed with lithium salt and calcined to obtain a single crystal high nickel lithium ion battery positive electrode material doped with X bulk phase and Y in-situ gradient doped. The preparation method of the invention is simple, the raw materials are easily obtained, and is suitable for large-scale industrial production.

Description

technical field [0001] The invention belongs to the technical field of positive electrode materials for lithium ion batteries, and in particular relates to a method for gradient doping and surface modification of positive electrode materials for single crystal high nickel lithium ion batteries. Background technique [0002] At present, lithium-ion batteries are widely used in portable electronic devices, new energy vehicles, smart grids, and even aviation and military industries due to their high voltage, high energy density, and long cycle life. In lithium-ion batteries, the specific capacity of cathode materials is lower than that of anode materials, and the cycle stability is poor, which is one of the important factors hindering the further development of lithium-ion batteries. key to development. [0003] In pursuit of higher energy density, high-nickel ternary cathode materials have received more and more attention and applications, especially the high capacity that ca...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/505H01M4/525H01M10/0525
CPCH01M4/505H01M4/525H01M10/0525H01M2004/028Y02E60/10
Inventor 杨成浩钟文涛
Owner SOUTH CHINA UNIV OF TECH