Positive pole piece for high-safety lithium ion battery as well as preparation method and application of positive pole piece

Abstract

The positive pole piece comprises a current collector and first safety coatings correspondingly arranged on the two outer side surfaces of the current collector, positive active layers are arranged on the two outer side surfaces of the first safety coatings, and the positive active layers are made of ternary positive materials. Second safety coatings are arranged on the two outer side surfaces of the positive electrode active layer, and end face safety coatings are arranged on the side edge end faces, except the tab position, of the positive electrode piece. The invention also discloses a preparation method of the positive pole piece, which comprises the following steps: uniformly stirring the raw materials to prepare each layer of slurry, sequentially coating the slurry on the current collector, and then stamping and coating the end surface; the invention also discloses an application of the positive pole piece in a lithium ion battery. Through the three-layer coating structure of the positive pole piece, the electrical performance and the safety performance of the lithium ion battery are ensured at the same time; the multi-layer coating method is adopted, so that the preparation efficiency is high; the positive pole piece is used as a composition structure of the lithium ion battery, so that the needling safety performance of the lithium ion battery is improved.

Description

technical field [0001] The invention belongs to the technical field of composite material preparation, and in particular relates to a high-safety lithium-ion battery positive pole piece and a preparation method and application thereof. Background technique [0002] In the positive electrode material of lithium ion battery, ternary materials such as lithium nickel cobalt manganese oxide (LiNiCoMnO 2 , abbreviated as NCM) or lithium nickel cobalt aluminate (LiNiCoAlO 2 , abbreviated as NCA) has a bright future because of its high energy density, but with the continuous improvement of energy density, safety issues have become increasingly prominent, so the improvement of its safety is imminent. Among the safety issues of lithium-ion batteries, acupuncture safety is the most difficult to break through. In the existing technology, methods to improve the safety of ternary materials acupuncture mainly include the use of vest structures, ceramic separators, and safety additives. Al...

AI Technical Summary

Problems solved by technology

Among the safety issues of lithium-ion batteries, acupuncture safety is the most difficult to break through. In the existing technology, the methods to improve the safety of ternary materials acupuncture mainly include the use of vest structures, ceramic separators, safety additives, etc., although these approach has been effective in improving security, but still falls short of higher security requirements

For example, the currently commonly used vest structure and other methods have the disadvantages of insignificant reduction in temperature rise and insignificant improvement in thermal runaway

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