High-nickel ternary positive electrode material as well as preparation method and application thereof

Abstract

The invention provides a high-nickel ternary positive electrode material as well as a preparation method and application thereof. The high-nickel ternary positive electrode material is prepared from a high-nickel ternary precursor, a lithium source and an additive for improving the grain strength, the additive for improving the grain strength is enriched at the grain boundary; the preparation method comprises the following steps: a) uniformly mixing a high-nickel ternary precursor and a lithium source in a ball mill at a high speed, and introducing an additive for improving the grain strength through low-speed mixing to obtain mixed powder; the speed of the high-speed mixing is 250 to 600 rpm (revolutions per minute); the speed of the low-speed mixing is 50 rpm to 200 rpm; and b) sintering, washing, drying and re-burning the mixed powder obtained in the step a) in sequence to obtain the high-nickel ternary positive electrode material. Compared with the prior art, the additive can be enriched at the grain boundary, the ternary positive electrode material which is strengthened in grain boundary, excellent in particle pressure resistance and good in chemical stability and thermal stability is obtained, and the cycle performance, the DCR performance and the gas production performance of the positive electrode material are obviously improved.

Description

technical field [0001] The invention relates to the technical field of high-nickel positive electrode materials, and more specifically relates to a high-nickel ternary positive electrode material and a preparation method and application thereof. Background technique [0002] At present, lithium cobalt oxide, lithium iron phosphate, lithium manganate and nickel cobalt lithium manganate ternary cathode materials are the most marketable types of materials. Among them, nickel-cobalt lithium manganese oxide ternary cathode material has high specific capacity, cycle stability, thermal stability and low price, and has achieved good applications in the fields of consumer electronics and power batteries. Nickel-cobalt lithium manganate ternary cathode materials are divided into different types such as 111, 523, 622, and 811 according to the ratio of nickel, cobalt, and manganese content. The specific capacity of the ternary material, when the nickel content ratio in the material is ...

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Problems solved by technology

In the co-precipitation process, the violent stirring leads to the disordered distribution and agglomeration of the primary particles, so there are different degrees of stress and distortion in the secondary particles, causing the material to easily form microcracks, which break during the cycle, resulting in cyclic diving and rapid DCR. growth and gas surge

[0004] The publication number is CN110862108A, which discloses a Chinese patent method for improving the electrochemical performance of high-nickel ternary cathode materials by doping fluorine modification, which fully grinds and calcines high-nickel precursors, lithium sources and lithium fluoride to obtain fluorine-doped The high-nickel doped ternary positive electrode material overcomes the defects of the high-nickel ternary positive electrode material to a certain extent by doping with fluorine ions, which can reduce the lithium-nickel mixing of the material and improve the stability of the material; but the above technical solution There is no research involving fluorine doping to improve particle strength, thereby improving cycle, DCR and gas production performance

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