Ternary positive electrode material with high volume energy density for lithium ion battery and preparation method

Abstract

The invention provides a method for preparing a ternary positive electrode material with a high volume energy density for a lithium ion battery. The method comprises the following steps: S1, uniformlymixing a ternary positive precursor, a lithium salt and a doping oxide; S2, pre-sintering the mixture in S1 in an oxygen or air atmosphere furnace, cooling the pre-sintered mixture naturally, addinga shape modifier into the pre-sintered material, and performing uniform mixing; and S3, sintering the material obtained in S2 in an oxygen or air atmosphere, so as to obtain a monocrystalline ternarypositive electrode material with the high volume energy density. The added shape modifier in the method is capable of controlling the amount of released lithium ions, reducing expansion and contraction degrees of a crystal in the process of charge and discharge, improving the stability of circulation, increasing the sizes of crystal particles, and improving the vibratory density of the material. By adopting the method provided by the invention, the monocrystalline ternary positive electrode material with the high volume energy density can be prepared by simply adding a certain amount of a sintering aid material to the mixture of the precursor and the lithium salt and keeping the temperaturein mixed gas at a certain temperature for a period of time.

Description

technical field

[0001] The invention relates to the technical field of lithium ion batteries, in particular to a method for synthesizing a high volume energy density single crystal ternary cathode material for lithium ion batteries. Background technique

[0002] With the development of globalization and the continuous progress of social economy, 3C digital electronic products are an indispensable part of people's colorful life. Lithium-ion batteries are chosen as power sources by developers of 3C products because of their high energy density, long service life, and relatively high safety. The types of cathode materials for lithium batteries commercialized on a large scale today are mainly: lithium iron phosphate (LiFePO 4 ), lithium manganate (LiMn 2 o 4 ), lithium cobalt oxide (LiCoO 2 ) and nickel-based ternary materials (LiNi x co y B 1-x-y o 2 ) (1≥x≥y≥0, B is Mn or Al). However, lithium iron phosphate cathode material

[0003] Because it needs to be nanometeri...

Images