A preparation method for dynamic coating of lithium-rich ternary lithium-ion battery positive electrode material by double-atmosphere roasting

Abstract

The invention discloses a preparation method of a double atmospheric roasted dynamically coated lithium-enriched ternary lithium ion battery anode material. The preparation method comprises the following steps: 1) weighing a manganese source, a nickel source and a cobalt source in a molar ratio to prepare a mixed salt aqueous liquid; 2) preparing a mixed alkaline liquid; 3) performing stepped temperature control reactions; 4) performing ageing, suction filtration and washing and drying to obtain a nickel, cobalt and manganese carbonate precursor; 5) performing double atmospheric roasting to obtain a nickel, cobalt and manganese oxide; 6) mixing the roasted product with a lithium source in a mixer according to a molecular formula of Li1.15Mn0.52Ni0.26Co0.07O2 to obtain a material III, wherein the lithium element is 2-5% excessive; 7) roasting the materials III in atmosphere to obtain a material IV, wherein the roasting temperature is 880-920 DEG C and the roasting time is 10-24h; 8) adding the material IV and deionized water into a reaction kettle and uniformly stirring the mixture; dropwise adding a titanyl sulfate liquid and ammonia water into the reaction kettle, controlling thepH of the reaction kettle to 9-11, and performing suction filtration and washing and drying after full reaction to obtain a material V; 9) performing dynamic lithium titanate coating; and 10) crushingand screening the material.

Description

technical field [0001] The invention belongs to the technical field of cathode materials for lithium-ion secondary batteries, and in particular relates to a preparation method for dynamically coating lithium-rich ternary lithium-ion battery anode materials by double-atmosphere roasting. Background technique [0002] The key to the popularization and application of new energy vehicles is to realize that their economy and convenience of use are equivalent to those of traditional fuel vehicles. The power battery is the core part of new energy vehicles. Lithium-ion batteries have obvious advantages in terms of cost and energy density, which can greatly improve the economy and convenience of use of new energy vehicles. The positive electrode material in the lithium-ion battery system is decisive factor. New energy vehicles should be fully or partially driven by electricity. Compared with traditional fuel vehicles, new energy vehicles can reduce fuel consumption. However, the sav...

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Problems solved by technology

However, the metal content of the carbonate precursor is very low, and there are two processes of carbonate decomposition and metal oxidation during the sintering process, which can easily lead to the rupture of spherical particles and affect the rolling density and processing performance of the product;

[0006] 2. The structure will change during the cycle, resulting in low initial Coulombic efficiency and poor cycle performance of the material

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