Hydrophobic high-nickel ternary positive electrode material and preparation method thereof

Abstract

The invention discloses a hydrophobic high-nickel ternary material and a preparation method thereof. The preparation method comprises the following steps: S1, preparing a fluorosilane solution; S2, preparing the hydrophobic high-nickel ternary positive electrode material; and S3, performing sintering heat treatment to obtain the high-nickel ternary positive electrode material with the hydrophobiclayer with the stable surface structure. Fluorosilane is hydrolyzed in an acidic environment, a hydrophobic layer is formed on the surface of the high-nickel ternary positive electrode material, and the surface structure of the high-nickel ternary positive electrode material is more stable through sintering heat treatment, so that the hydrophobicity of the high-nickel ternary material is realized,the homogenate and coating processability of the high-nickel ternary positive electrode material is improved, a pole piece is prevented from storing and absorbing water, the side reaction of moistureand electrolyte is reduced, the electrical property of the lithium ion battery is obviously improved, meanwhile, the preparation process is simple, the cost is low, and industrialization is easy to realize.

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 hydrophobic high-nickel ternary positive electrode material and a preparation method thereof. Background technique [0002] Today, Li-ion batteries are required to have higher and higher energy densities, and thus the gram capacities of the selected active materials are also increasing. At present, the positive electrode active materials are mainly dominated by ternary materials, and the ternary positive electrode materials are from the initial LiNi 1 / 3 co 1 / 3 mn 1 / 3 o 2 (NCM111) to now LiNi 0.8 co 0.1 mn 0.1 o 2 (NCM811), even higher nickel content, everything is to improve the reversible capacity of active cathode materials, so as to meet the requirements of increasing the energy density of lithium-ion batteries. However, the nickel content of the high-nickel ternary positive electrode material of the lithiu...

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Problems solved by technology

However, the nickel content of the high-nickel ternary positive electrode material of the lithium-ion battery is too high, resulting in an excessively high pH value of the surface itself. During the configuration of the slurry, the slurry is very easy to absorb moisture (absorbing water), making the slurry appear in a jelly state, thereby The slurry cannot be coated, and the subsequent pole piece absorbs a lot of moisture, which will also lead to a sharp drop in battery performance, which greatly reduces the industrialization of high-nickel ternary cathode materials for lithium-ion batteries.