In-situ gradient doped single crystal high-nickel lithium-ion battery high-voltage positive electrode material and preparation method thereof

Abstract

The invention belongs to the technical field of lithium-ion battery cathode material preparation, and discloses an in-situ gradient doped single-crystal high-nickel lithium-ion battery high-voltage cathode material and a preparation method thereof. Nickel salt, cobalt salt and manganese salt are weighed and dissolved together in Prepare solution X in deionized water; weigh soluble A salt and B salt and dissolve in deionized water respectively to prepare solution Y and solution Z; dissolve soluble alkali and ammonia water in deionized water together, and mix solution X, mixed alkali solution, solution Y and solution Z are pumped into the reaction kettle; after the addition is completed, stand for aging, the precipitate is filtered, washed, and dried to obtain single crystal Ni x co y mn z A a B b (OH) 2 Precursor; the single crystal Ni x co y mn z A a B b (OH) 2 After the precursor is uniformly mixed with the lithium salt, it is calcined to obtain the single crystal high-nickel lithium-ion battery cathode material LiNi with A and B in-situ gradient doping. x co y mn z A a B b o 2 . The preparation method of the invention is simple, and the raw materials are easy to obtain.

Description

In-situ gradient doped single-crystal high-nickel lithium-ion battery high-voltage cathode materials and their preparation method technical field The invention belongs to the technical field of lithium ion battery high-voltage positive electrode material preparation, in particular to a kind of in-situ gradient doping A high-voltage positive electrode material for a hetero single crystal high-nickel lithium ion battery and a preparation method thereof. Background technique At present, lithium-ion batteries are widely used due to their high voltage, high energy density, long cycle life and other advantages. Portable electronic equipment, new energy vehicles, smart grids and even aviation and military industries. In lithium-ion batteries, relative to negative Electrode materials, the specific capacity of cathode materials is low, and the cycle stability is poor, which is an important obstacle to the further development of lithium-ion batteries. One of the factors, th...

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Problems solved by technology

[0005] (1) The stress generated by the multi-phase transformation process of traditional ternary materials during the cycle causes spherical particles to start to appear microcracks at the grain boundaries of the primary particles, and the microcracks further expand during the cycle, seriously deteriorating the cycle life of the battery and Reversible capacity

[0006] (2) The simple single crystal particle structure has limited mitigation effect on microcracks, which is not enough to support the long-term cycle of ternary materials under high voltage state

[0008] The difficulty in solving the above problems and defects is that the cathode materials of lithium-ion batteries have more complex and variable multi-phase structural transitions in the high-voltage range, and these structural transitions will make the stress concentration of material particles more obvious, thus causing greater stress. Structural damage and the generation and deterioration of microcracks seriously affect the cycle stability and service life of battery materials in high voltage regions

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