Lithium cobalt oxide composite material particle, preparation method thereof, and lithium ion battery

Abstract

The invention relates to a lithium cobalt oxide composite material particle. The lithium cobalt oxide composite material particle comprises a positive active substance particle and an aluminum phosphate layer coated on the surface of the positive active substance particle, wherein the positive active substance particle is a lithium cobalt oxide particle or a doped lithium cobalt oxide particle. The invention also relates to a preparation method of the positive composite material particle of a lithium ion battery. The preparation method comprises the following steps: 1, preparing an aluminum nitrate solution; 2, adding the positive active substance material for coating to the aluminum nitrate solution with controlling the adding amount of the positive active substance particle to form a mixture; 3, adding a phosphate solution to the mixture, and reacting to form the aluminum phosphate layer on the surface of the positive active substance particle; and 4, carrying out heat treatment on the positive active substance particle with the surface coated with the aluminum phosphate layer to obtain the positive composite material particle. The invention also relates to the lithium ion battery.

Description

technical field [0001] The invention relates to a lithium cobalt oxide composite material particle and a preparation method thereof, and a lithium ion battery, in particular to a lithium cobalt oxide composite material particle formed by compounding with aluminum phosphate, a preparation method thereof, and a lithium ion battery. Background technique [0002] Coating the particle surface of the positive electrode active material of the lithium ion battery with other materials is a common method for modifying the positive electrode active material in the prior art. For example, coating a layer of carbon on the surface of lithium iron phosphate particles can effectively solve the problem of low conductivity of lithium iron phosphate, so that lithium iron phosphate coated with a carbon layer has better conductivity. In addition, the prior art has shown that coating aluminum phosphate on the surface of lithium cobalt oxide or other positive electrode active material particles ca...

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Problems solved by technology

Therefore, the aluminum phosphate coating layer formed on the surface of the positive electrode active material by the above method is not uniform enough, and it is impossible to ensure that the surface of each positive electrode active material can be uniformly coated with a layer of aluminum phosphate, so that the lithium ion battery using the positive electrode active material The cycle performance is not good, making this method difficult for large-scale industrial application

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