Preparation method for porous spherical lithium nickel cobalt manganate used as ternary positive electrode material of lithium ion battery

Abstract

The invention discloses a preparation method for porous spherical lithium nickel cobalt manganate used as a ternary positive electrode material of a lithium ion battery, and relates to the technical field of an electrode material of the lithium ion battery. The positive electrode material is a lithium nickel cobalt manganate (NCM) three-component positive electrode material, and the chemical formula is LiNi<x>Co<y>Mn<z>O<2>, wherein x, y z are equal to 0-1, and x+y+z is equal to 1; the preparation method specifically comprises the steps of preparing a ternary positive electrode material precursor and performing high-temperature sintering to prepare the porous spherical ternary positive electrode material. By taking NH<4>HCO<3> as a complexing agent, the technological process is simplified and the production cost is lowered; by pumping CO<2> gas, Li<2>CO<3> with quite low solubility in water at a normal temperature is converted into LiHCO<3> with high solubility, so that more uniform mixing can be achieved; and the prepared porous framework-shaped ternary positive electrode material can shorten lithium ion diffusion path in the charging and discharging process, and improve the rate capability of the lithium ion battery.

Description

[0001] Technical field: [0002] The invention relates to the technical field of lithium-ion battery electrode materials, in particular to a method for preparing porous spherical nickel-cobalt lithium manganese oxide as a ternary positive electrode material for lithium-ion batteries. [0003] Background technique: [0004] With the continuous development of new energy sources and the increasing emphasis on environmental protection, lithium-ion batteries, which are environmentally friendly, are shining brightly in the fields of electronic consumption and power supply. with LiCoO 2 、LiFePO 4 , Li 2 mn 2 o 4 Compared with commonly used positive electrode materials, ternary layered structure positive electrode materials have the advantages of high reversible capacity, stable structure, high thermal stability and low cost. It has broad application prospects in high energy density devices. [0005] At present, the preparation method of the commercial ternary cathode material on...

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Problems solved by technology

On the other hand, the abnormal fluctuation of pH value will lead to excessive particle size distribution of the product and poor product consistency, which will eventually affect the tap density and electrochemical performance of the product

If using NH 3 H2O is used as a complexing agent, and the pH control accuracy is very high in the precipitation process, while the PID adjustment control equipment for online monitoring and automatic adjustment of pH changes is relatively expensive, resulting in increased production costs

The traditional sintering system is directly mixed with lithium and then sintered. The spherical nickel-cobalt-manganese oxide with a single shape and a dense surface is used as the positive electrode material during the use of lithium batteries, which is not conducive to the infiltration of the electrolyte and the shortening of lithium ions during charging and discharging. Diffusion paths, poor rate performance

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