Preparation method of copper-doped ternary positive electrode material

Abstract

The invention provides a preparation method of a copper-doped ternary positive electrode material. The method comprises the steps that soluble nickel salt, cobalt salt, manganese salt and copper saltare taken and formulated into a solution A according to an element molar ratio Ni:Co:Mn:Cu=x:y:z:1-x-y-z, wherein x is between 1/3 and 0.9, y is between 0 and 1/3, z is between 0 and 1/3, 1-x-y-z is between 0 and 0.1; a complexing agent is taken to prepare a solution B; a precipitant is taken to prepare a solution C; a complexing agent aqueous solution is added into a reaction kettle and used as abottom liquid; the above solution is added into the reaction kettle; the pH is controlled to be 10 to 11. 6, and the reaction temperature is 50 to 55 DEG C; stirring is carried out; under the protection of inert gas, coprecipitation reaction is carried out, and then the product is filtered, washed to neutral and dried to acquire a precursor M; and the precursor M and lithium salt are mixed and sintered by oxygen, wherein the calcination temperature is 520 to 550 DEG C, the calcination time is 3 to 4.5 h, the sintering temperature is 820 to 849 DEG C, the sintering time is 10 to 14 h, the heating rate is 4 to 6 DEG C /min. The prepared copper-doped ternary positive electrode material is suitable for industrial mass production. The electrochemical performance of the product is stable.

Description

technical field [0001] The invention relates to the technical field of electrode materials, in particular to a method for preparing a copper-doped ternary positive electrode material. Background technique [0002] Copper-doped ternary cathode materials (Li n Ni x co y mn z Cu 1-x-y-z o 2 , where 1≦n≦1.2, 1 / 3≦x≦0.9, 0≦y≦1 / 3,0≦z≦1 / 3,0≦1-x-y-z≦0.1) methods mainly include sol-gel method and Solid phase sintering method. [0003] The process of synthesizing copper-doped ternary cathode materials by sol-gel method: Weighing quantitative Mn(CH 3 COO) 2 4H2O, Co(CH 3 COO) 2 4H 2 O, Ni(CH 3 COO) 2 4H2O, Li(CH 3 COO) 2H2O, Cu(CO 2 CH 3 )2·H 2 O, dissolved in deionized water 50mL, lithium acetate 5% or more. Then, an appropriate amount of citric acid solution (citric acid / transition metal molar ratio of 1:1) was added to the above solution, and the resulting solution was heated at 80° C. and stirred until a hydrogel was formed. The hydrogel was then placed in a vacuu...

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Problems solved by technology

The solid-phase sintering method mainly uses mechanical means to mix and refine raw materials, which can easily lead to uneven microscopic distribution of raw materials, making it difficult for the diffusion process to proceed smoothly. At the same time, impurities are easily introduced during the mechanical refinement process, and the calcination temperature is high. Long calcination time, high energy consumption, serious loss of lithium, difficult to control the stoichiometric ratio, easy to form impurity phases, large differences in product composition, structure, particle size distribution, etc., resulting in unstable electrochemical performance of the product

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