Method for preparing lithium ion battery positive electrode composite material

Abstract

This invention discloses a preparation method for the positive complex material of Li ionic cells, which applies a surface covering technology to cover an Al2O film of amorphous structure on a positive active substance surface of the Li ionic cells, confects the Al salt and a solvent to a soluble Al salt solution then mixes it with the positive active substance in proportion and mix them uniformly then to get a positive complex material of Li ionic cell with an amorphous structure Al2O film covered on the surface after filtration, sinter and cool naturally, which improves the interface state of the electrolyte and positive active substance and suppresses the badness reaction between the two.

Description

technical field [0001] The invention belongs to the technical field of functional ceramics and chemical power sources, and in particular relates to a preparation method of a lithium-ion battery positive electrode composite material which uses surface coating technology to synthesize composite material powder with a core-shell structure. Background technique [0002] Lithium-ion batteries are widely used in mobile electronic appliances, such as mobile phones, cameras, notebook computers, etc. As lithium-ion batteries are expected to be popularized and applied in electric vehicles or power storage power supplies, etc., cathode materials have become the key to restricting the performance-price ratio of lithium-ion batteries one of the elements. At present, the cathode material widely used commercially is mainly LiCoO 2 , its actual capacity is about 140-150mAh / g, and resources are scarce and expensive. LiCoO 2 The cycle capacity is stable at 3.8V vs. Li, and the discharge ca...

AI Technical Summary

Problems solved by technology

Since the anhydrous electrolyte is easy to spontaneously decompose under high voltage and high temperature, the decomposed HF, CH 4 , CO, etc. These decomposition products will not only corrode the positive electrode material, but also worsen the adverse reaction between the electrolyte and the positive electrode material, resulting in deterioration of battery cycle performance and even endangering the safety of the battery; other positive electrode materials such as LiNi 0.7 co 0.3 o 2 Li(NiCoMn) 1 / 3 o 2 , LiMn 2 o 4 etc. have the disadvantages of poor charging resistance and unstable performance at high temperature (such as 60°C)