A kind of lithium ion battery ternary positive electrode material and preparation method thereof

Abstract

The present invention discloses a lithium-ion battery ternary cathode material and a method for preparing it, comprising a ternary material and an overmolding layer clad in the surface of the ternary material, including Li in the coating layer 2+x C 1‑x B x O 3 Coating agent, wherein 0< x<1. The preparation method steps are: (1) the ternary cathode material precursor is mixed with the lithium source and the dopant to obtain a calcined sample powder; (2) the primary calcination sample powder is dispersed into an alkaline solution, stirred to make it sufficiently moist, filtered and dried in a vacuum environment, and then calcined twice to obtain a secondary calcination sample powder; (3) the secondary calcination sample powder and including Li 2+x C 1‑x B x O 3 The coating material of the coating agent is evenly mixed and then calcined three times. The present invention by improving the coating agent and the preparation method, coating a layer of lithium ion conductivity material on the surface of the ternary cathode material, effectively improving the capacity performance and cycle performance of the battery.

Description

technical field [0001] The invention relates to the field of positive electrode materials for lithium ion batteries, in particular to a ternary positive electrode material for lithium ion batteries and a preparation method thereof. Background technique [0002] With the development of new energy vehicles, lithium-ion power batteries have attracted much attention as the most popular electric vehicle power batteries. Compared with the mature and stable graphite anode, the research and development of cathode materials with high capacity, long life, low cost, safety and environmental protection is particularly urgent. The currently commonly used cathode materials for lithium batteries mainly include layered lithium cobaltate, ternary materials, spinel-structured lithium manganate and olivine-structured lithium iron phosphate. Ternary materials have high specific capacity, energy density and power density, and relatively stable performance, so they have become popular materials ...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to overcome the problem that the introduction of B will reduce the lithium ion conductivity of the material when the boron-containing coating agent is used to coat and modify the ternary positive electrode material in the prior art, thus affecting the performance of the battery, and provides a lithium ion battery The ternary positive electrode material and its preparation method, by improving the coating agent and the preparation method, a layer of material with high lithium ion conductivity is coated on the surface of the ternary positive electrode material, and the capacity performance of the material is improved while reducing ions. Resistivity improves the rate performance; at the same time, the coating layer can effectively slow down the side reaction between the ternary material and the electrolyte, improve its cycle performance and prolong the battery life