Ternary anode material, preparation method thereof and lithium-ion battery containing material

Abstract

The invention relates to the field of lithium-ion batteries and discloses a ternary anode material, a preparation method thereof and a lithium-ion battery containing the material. The process comprises the steps that a ternary anode material and conductive inorganic salt are mixed uniformly and dissolved in a solvent to obtain a first mixed solution, and the solvent in the first mixed solution isdried by distillation to obtain mixed powder; the mixed powder is calcined to obtain a calcination product containing ternary anode material particles coated with an inorganic lithium salt compound; an oxidant, conductive polymer monomers and the calcination product are dissolved in a solvent to obtain a second mixed solution, the conductive polymer monomers are subject to oxidative polymerizationto generate a conductive polymer, and the outer layer of the inorganic lithium salt compound of all the ternary anode material particles is coated with the conductive polymer; and the mixed solutionis filtered, washed and dried, and then the ternary anode material of the lithium-ion battery is obtained. The technical scheme is beneficial for suppressing side effects of an electrolytic solution on the surface of the high-nickel ternary anode material; the first discharge capacity of the lithium-ion battery is improved; and rate discharge and circulation properties of the high-nickel ternary anode material are enhanced.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, and discloses a ternary positive electrode material, a preparation method thereof and a lithium ion battery containing the material. Background technique [0002] Since Sony successfully commercialized lithium-ion secondary batteries in 1993, after more than 20 years of development, lithium-ion batteries represented by lithium cobalt acid have occupied most of the consumer battery market. The current strong environmental awareness and policies of the government and society are promoting With the development of electrification of lithium batteries, high-nickel ternary cathode materials have the advantages of high energy density and low cost compared with conventional lithium cobalt acid and lithium iron phosphate materials, so they have become one of the main research and development directions of enterprises and research institutes. However, most of these materials have problems such as serio...

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Problems solved by technology

[0003] In recent years, many domestic companies have adopted new high-temperature sintering technology to synthesize micron-sized high-nickel and low-column ternary single crystal particles similar to lithium cobaltate. The prepared micron-sized primary single crystal particles have small particles and more complete crystal structure. , high compaction density and excellent electrode processing performance, although it has greatly reduced the micro-crack phenomenon caused by the expansion of particles similar to the secondary particle positive electrode material during charge and discharge, and improved the cycle and safety performance of the battery. However, the reduction of cobalt content usually leads to problems such as a decrease in electronic conductivity and an unstable layered structure. At the same time, high-nickel ternary cathode materials are prone to metal and oxygen atom dissolution under the state of highly deintercalated lithium. Nickel ternary primary single crystal particles still face defects such as low initial charge and discharge efficiency, serious capacity loss, and poor rate performance during high-voltage charge and discharge.

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