Security lithium ion battery positive plate as well as preparation method thereof

Abstract

The invention discloses a security lithium ion battery positive plate as well as a preparation method thereof. The positive plate is of a multi-layer structure, and comprises the following active substances: lithium manganese phosphate LiMnPO4, nickel-cobalt-manganese ternary material Li(NixCOyMnz)O2 (0x being more than 0 and smaller than or equal to 0.8, y being more than 0 and smaller than or equal to 0.4, and Z being more than or equal to 0 and less than or equal to 0.4, and x+y+z being equal to 1), as well as a high-temperature-resistant nano material, namely A12O3 or SiO2; the mass percentage of the active substances is that the high-temperature resistant A12O3 or SiO2 ceramic material:LiMnPO4:Li(NixCOyMnz)O2 is equal to (1%-5%):(1%-98%): (1%-98%). The preparation method of the positive plate can be in a sandwiched structure, and also the surface of aluminum foil can be coated with lithium manganese phosphate LiMnPO4 and the Nickel-Cobalt-Manganese ternary material Li(NixCOyMnz)O2 by adopting a mechanical mixing mode, and the surface of aluminum foil can be coated with a layer of high-temperature-resistant nano material; the lithium ion battery prepared by the plate with the structure has favorable safety performance; the long cycle performance and the safety performance of the lithium ion battery can be improved obviously by utilizing the opposite crystal cell volume variation characteristics of different active substances in the charge and discharge processes as well as the excellent liquid retention capability to electrolyte by A12O3 or SiO2.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, in particular to a positive electrode sheet of a safe lithium ion battery and a preparation method thereof. Background technique [0002] Lithium-ion batteries are advanced storage batteries developed in the early 1990s. Compared with traditional secondary batteries such as nickel-hydrogen batteries, nickel-cadmium batteries, and lead-acid batteries, they have high specific energy, high voltage, long life, and high and low temperature performance. A series of advantages such as excellent, low self-discharge rate and no memory effect. Since its inception, the market share of lithium-ion batteries has continued to increase, and has occupied more than 80% of the civilian small secondary battery market. preferred. [0003] In the field of new energy vehicles, battery life, service life and safety performance are the biggest competitiveness of electric vehicles, and they are also the m...

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to overcome the deficiencies of the current technology, solve the problem of poor safety performance of high specific energy power lithium-ion batteries, and provide a preparation method for lithium-ion battery positive plates that take into account both high energy density and high safety, thereby effectively Improve the long-term cycle performance of the battery, and play a role in increasing the cruising range of electric vehicles

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