A kind of preparation method of high cycle efficiency electrode and its application

Abstract

The invention provides a preparation method and application of an electrode with high cycle efficiency. The method comprises: rolling, flat pressing, air pressure or hydraulic pressure on a metal source and a metal electrode to be supplemented to realize physical bonding and contact, and controlling the metal source under vacuum or inert atmosphere After the temperature treatment, the metal source is peeled off to obtain an electrode with high cycle efficiency; the metal electrode to be supplemented is selected from a negative electrode capable of migrating metal or a positive electrode capable of migrating metal; the metal source is a lithium source or a sodium source. The method only needs to physically bond and contact the metal source and the metal electrode to be supplemented, and then treat it in a vacuum or an inert atmosphere for a certain period of time to obtain an electrode with high cycle efficiency. The method is simple; and the metal electrode to be supplemented has both electronic conductivity and ionic conductivity. Therefore, the metal source will undergo a metal intercalation process to the metal electrode to be supplemented; there is also a diffusion process of metal elements in the physical adhesive contact, so that the electrode has a high first cycle efficiency and good cyclability. The battery made of the electrode has high first cycle efficiency and capacity retention rate.

Description

technical field [0001] The invention belongs to the technical field of pole pieces, and in particular relates to a preparation method and application of a high cycle efficiency electrode. Background technique [0002] With the development of the electric vehicle industry, people have higher and higher requirements for energy density and cyclability. For the negative electrode, although it has a large theoretical specific capacity, such as silicon and tin alloy materials, which is much larger than the theoretical specific capacity of graphite materials, the volume expansion of the alloy material after lithium storage is serious, which leads to the powdering of the silicon negative electrode coating and the accumulation of lithium. The fluid falls off and the cycle life is extremely poor. When silicon-oxygen material is used as the negative electrode material of lithium-ion battery, the volume expansion problem after lithium storage can be greatly improved, but the first effi...

AI Technical Summary

Problems solved by technology

[0007] To sum up, there are the following problems: the method of using lithium powder for lithium supplementation requires extremely high uniformity of lithium powder particles, and requires extremely high surface flatness of the pressing roller, which is difficult to guarantee in actual use. conditions, resulting in low quality of lithium supplementation: Ultra-thin metal lithium strips are not easy to obtain at present, especially ultra-thin lithium strips that require a very small thickness error, assuming that a layer of 3 μm is required Lithium, if a point is 0.1 μm more than the average, then the point is 3.33% larger than the average value. The difficulty of using ultra-thin lithium strips for lithium supplementation is to first obtain ultra-thin lithium strips, even if the problem of ultra-thin lithium strips is solved. , but also face the problem that the ultra-thin lithium ribbon is easy to wrinkle and break; if the lithium supplement needs to use the electrolyte, it is necessary to solve the problem of dryness of the pre-intercalated lithium powder or dryness of the electrode after lithium supplementation

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