Lithium cobalt oxide cathode material and preparation method thereof

Abstract

The invention provides a preparation method of a lithium cobalt oxide cathode material. The method comprises the following steps: (1), dispersing lithium cobalt oxide and soluble lithium salt into a dispersion system A of soluble organic aluminum salt at a temperature of 50-80 DEG C to obtain a mixture B, the dispersion system A comprising soluble organic aluminum salt, a complexing agent and ethanol serving as a solvent; (2), reacting the mixture B in a closed container at 120-150 DEG C for 8-15 hours, performing washing, collecting solids and drying; and (3), grinding the solid obtained in the step (2), and performing calcining at 600-900 DEG C for 12-20 hours to obtain the lithium cobalt oxide cathode material coated with lithium metaaluminate. According to the preparation method of the lithium cobalt oxide cathode material, the surface of lithium cobalt oxide is coated with lithium metaaluminate, and the soluble organic aluminum salt, the complexing agent and the soluble lithium salt are sequentially coated under solvent heating and calcining conditions, so that aluminum metaaluminate coating is more uniform, and the stability of the lithium cobalt oxide positive electrode material under a high-temperature condition is remarkably improved; and the cycle performance of the high-voltage lithium ion battery can be more effectively improved.

Description

technical field [0001] The invention relates to a lithium battery positive electrode material, in particular to a lithium cobalt oxide positive electrode material and a preparation method thereof. Background technique [0002] In recent years, with the vigorous development of the 3C market and the sudden emergence of new energy vehicles, people have put forward higher and higher requirements for the performance of lithium-ion batteries, especially in terms of energy density. Improving the working (charging) cut-off voltage of lithium-ion batteries is the most direct and effective way to increase energy density. However, the high cut-off voltage poses new requirements and challenges for the stability of cathode materials and electrolytes. [0003] Surface coating can significantly improve the stability of lithium-ion battery cathode materials, especially when the battery operating voltage is high. Metal oxides such as Al 2 o 3 , effectively improving the structural stabil...

AI Technical Summary

Problems solved by technology

But Al 2 o 3 The coating will inhibit the migration of lithium ions at the interface of the positive electrode, deteriorating the performance of lithium-ion batteries

Moreover, the existing lithium cobalt oxide cathode materials have poor battery performance under high temperature conditions

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