A kind of preparation method of large particle size single crystal lithium ion battery ternary cathode material

Abstract

The invention discloses a preparation method of a ternary cathode material for a large-grained single-crystal lithium-ion battery. First, the ternary precursor Ni with a D50 of 3‑5um was prepared by co-precipitation 1‑x‑y co x m y (OH) 2 ; The precursor prepared by co-precipitation and the lithium source are mixed evenly by wet method, and then combined and dried; finally, the mixed material after the precursor and the lithium source is mixed and dried is put into the rotary furnace, and oxygen is passed through, and the mixed material is rotated in the rotary furnace. The rotation of the furnace is stirred and flipped while being sintered at high temperature, and the reaction occurs. This dynamic sintering enables the mixture to fully contact with oxygen, reduces oxygen vacancies, and improves the final sintered material LiNi 1‑x‑y co x m y o 2 In addition, the material recrystallizes under high temperature conditions in a dynamic environment, which inhibits the agglomeration between particles, so that each primary particle can be uniformly dispersed, thereby producing a large-size single-crystal ternary cathode material.

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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