Preparing method of large-granularity single-crystal lithium ion battery three-element positive electrode material

Abstract

The invention discloses a preparing method of a large-granularity single-crystal lithium ion battery three-element positive electrode material. The method includes the steps of preparing a three-element precursor Ni1-x-y-CoxMy(OH)2 with the D50 of 3-5 micron through a coprecipitation method, evenly mixing the precursor prepared through coprecipitation and a lithium source through a wet method, conducting chemically combining and drying, putting the mixed and dried mixture of the precursor and the lithium source in a rotary furnace, introducing oxygen, and stirring, turning and sintering the mixture in the rotary furnace at a high temperature when the rotary furnace rotates for having a reaction. By means of the dynamic sintering, the mixture can make sufficient contact with oxygen, oxygenvacancy is reduced, the crystallinity degree of the final sintering material LiNi1-x-y-CoxMyO2 is improved, the recrystallization of the materials at a high temperature happens in the dynamic environment, the particle aggregation is restrained, the particles are evenly dispersed, and therefore the large-granularity single-crystal lithium ion battery three-element positive electrode material is prepared.

Description

technical field [0001] The invention belongs to the field of lithium ion battery materials, and in particular relates to a preparation method of a lithium ion battery ternary cathode material. Background technique [0002] In recent years, the rapid rise of new energy vehicles has driven the development of power batteries, and put forward more stringent requirements for batteries. While meeting safety and high cycle performance, they must also have high energy density to meet the needs of electric vehicles. The battery life of the car. In lithium ion batteries, compared with negative electrode materials, the lower gram capacity and compaction density of positive electrode materials are the main factors restricting the high energy density of lithium ion batteries. Lithium-ion ternary cathode materials, especially high-nickel material LiNi 0.8 co 0.1 mn 0.1 o 2 and LiNi 0.8 co 0.15 al 0.05 o 2 Because of its large gram capacity, it is favored by researchers, but most ...

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Problems solved by technology

[0003] First: there are more gaps between the primary particles, which not only reduces the compacted density of the material, but also increases the specific surface area of ​​the material, and more particles are in contact with the electrolyte, increasing the number of side reactions; second: by primary The secondary spheroidal material formed by agglomeration of particles is easy to be crushed when the rolls are facing each other during the production process of the pole piece; third: after the battery has been cycled for many times, the agglomerated spheroids are easy to pulverize

[0004] In response to such problems, researchers have prepared single-crystal lithium-ion ternary cathode materials. In CN104979546A published in 2015, the preparation method of lithium-ion battery ternary cathode materials with single-crystal morphology is obtained by adding co-solvent and high-temperature calcination. Lithium-ion battery ternary cathode material, but this process requires the addition of co-solvent and multiple high-temperature sintering at 900-1000 ° C. The obtained single crystal material has a small particle size, with a maximum particle size of about 1 μm

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