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

Abstract

The invention provides a ternary positive electrode material for a lithium ion secondary battery and a preparation method thereof. The method of the invention can improve the electronic conductivity and ionic conductivity of the ternary positive electrode material for a lithium ion secondary battery under low temperature conditions, thereby improving the ternary positive electrode material. Low temperature output characteristics of cathode materials. The preparation method includes the following steps: 1) adding a metal oxide to a ternary precursor A with a median particle size of 3-5 μm and adding a lithium source to obtain a material A; adding a ternary precursor A with a median particle size of 8-12 μm Add a metal oxide to the precursor B and add a lithium source to obtain a material B; sinter to obtain a calcined material A and B; 2) respectively add it to the gelatin aqueous solution, stir and dry to obtain a gel A and a gel B; 3) freeze the The dried gels A and B are calcined to obtain secondary sintered materials A and B coated with conductive carbons of different coating amounts; 4) batch mixing of secondary sintered materials A and B to obtain lithium ion secondary battery III Element cathode material.

Description

technical field [0001] The invention belongs to the technical field of positive electrode materials for lithium ion batteries, and in particular relates to a high-nickel ternary positive electrode material with excellent performance and a preparation method thereof. Background technique [0002] Lithium-ion secondary batteries have been rapidly applied to all aspects of people's production and life since their inception due to their high specific discharge capacity, long cycle life, low self-discharge rate, and good environmental friendliness. However, with the rapid development of the new energy industry, power batteries have put forward higher requirements for energy density, safety, and cycle life, and conventional lithium-ion batteries are therefore also faced with huge challenges. At present, ternary materials have received extensive attention due to their high discharge specific capacity and energy density. [0003] Ternary materials are composed of microspheres with ...

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Problems solved by technology

[0003] The ternary material is composed of microspheres of different particle sizes, among which the microspheres with large particle sizes have a smaller specific surface area, and less side reactions occur during the battery cycle, which is conducive to improving the safety of the battery; but due to the specific surface area Smaller, larger particle size microspheres have lower lithium ion conduction efficiency, which is not conducive to the capacity of the battery under low temperature conditions

Microspheres with small particle size are just the opposite. Their specific surface area is large, which is conducive to the rapid conduction of lithium ions, thereby improving the rate performance of the material and improving the cycle performance of the battery under low temperature conditions; but similarly, microspheres with small particle size The specific surface area of ​​the ball is large, and side reactions are prone to occur, which is harmful to the safety of the battery

[0004] At present, ternary materials have defects such as short cycle life and poor safety, especially under low temperature conditions, the discharge capacity and cycle stability of ternary materials will be greatly attenuated

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