Lithium cobalt oxide-coated lithium nickel cobalt aluminate positive electrode material and preparation method thereof

Abstract

Disclosed are a lithium cobalt oxide-coated lithium nickel cobalt aluminate positive electrode material and a preparation method thereof. Lithium cobalt oxide accounts for 1-10wt% of the material based on mass percentage composition; lithium cobalt oxide forms a coating layer with thickness of 5-30nm to coat lithium nickel cobalt aluminate; and the positive electrode material is spherical particles with the grain diameter of 5-15[mu]m. The preparation method comprises the following steps of (1) dissolving a water soluble surfactant into water, and heating to perform an ultrasonic stirring reaction; (2) adding aluminum nickel cobalt hydroxide, soluble cobalt salt and soluble lithium salt synchronously, and heating to perform an ultrasonic stirring reaction; (3) performing spraying and drying while ultrasonic stirring; and (4) putting the product into a tubular furnace and performing two-stage sintering in oxidizing atmosphere. The positive electrode material disclosed in the invention has relatively high cycle stability and high-rate discharging performance; by virtue of the method, the problem of surface residue existing the conventional coating can be lowered effectively; and themethod is low in cost, simple in process and suitable for massive industrial production.

Description

technical field [0001] The invention relates to a positive electrode material and a preparation method thereof, in particular to a lithium cobalt oxide-coated nickel cobalt lithium aluminate positive electrode material and a preparation method thereof. Background technique [0002] With the continuous consumption of petroleum energy, lithium-ion batteries, as a new energy source, have attracted increasing attention due to their advantages such as good safety, high discharge specific energy, and long charge and discharge life, and the positive electrode material in lithium-ion batteries is the most critical Partly, cathode materials such as lithium cobalt oxide, lithium iron phosphate, and lithium manganese oxide currently used in the market have been difficult to meet market demand. [0003] Nickel-cobalt lithium aluminate has low price, high compaction density, high gram capacity, and higher volume specific capacity than lithium cobalt oxide. It has wide application prospec...

AI Technical Summary

Problems solved by technology

[0002] With the continuous consumption of petroleum energy, lithium-ion batteries, as a new energy source, have attracted increasing attention due to their advantages such as good safety, high discharge specific energy, and long charge and discharge life, and the positive electrode material in lithium-ion batteries is the most critical Partly, cathode materials such as lithium cobalt oxide, lithium iron phosphate, and lithium manganese oxide currently used in the market have been difficult to meet market demand

[0003] Nickel-cobalt lithium aluminate has low price, high compaction density, high gram capacity, and higher volume specific capacity than lithium cobalt oxide. It has wide application prospects. However, due to the high nickel content, there are some problems in the application process: The cation mixing of nickel and lithium leads to poor cycle stability and other problems

However, this operation may make the coating layer uneven and affect the electrochemical performance

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