A kind of lithium battery sico-si gradient thin film electrode system and preparation method

Abstract

The invention discloses a lithium battery SiCO-Si gradient thin film electrode system. The system comprises a monocrystalline silicon substrate, wherein the monocrystalline silicon substrate is provided with a TiN barrier layer, an Al thin film layer, a SiAlCO thin film layer, a SiCO thin film layer, a SiO[1 / 3] thin film layer and a Si thin film layer from bottom to top in sequence. According to the system, by combining the two potential negative electrode materials, namely SiCO and silicon, through gradient design of specific capacity and mechanical property, the advantages of the two materials are comprehensively realized, and the disadvantages of the two materials are complemented. The thin film system prepared with the magnetic control sputtering method and target materials such as silicon, aluminum and graphite has the advantages of being high in adhesiveness, low in cost, controllable in constituent, low in temperature and the like. Through nanocrystallization of the SiCO surface, lithium diffusion and interface bonding strength are further improved, and the novel thin film electrode system with excellent electrochemical property and interface mechanical property is obtained finally. Furthermore, the method for preparing the SiCO nanometer surface with the chemical corrosion method has the advantages that the process is simple and quick, no expensive instrument is needed, raw materials are rich and cheap, and nanotopography is controllable.

Description

technical field [0001] The invention relates to the field of a multilayer thin film electrode system, in particular to a SiCO-Si gradient thin film electrode system for a lithium battery and a preparation method thereof. Background technique [0002] Lithium ion has a series of advantages such as high energy, long service life, light weight, small size, etc., which has attracted widespread attention and attention from the international battery industry and the scientific and technological circles. Lithium battery applications mainly include energy storage batteries for portable devices and power batteries for new energy vehicles. The former mainly includes 3C products, namely computers, communications and consumer electronics products. The number of global mobile phone users is increasing at a rate of about 15%-25%, and the development of notebook computers that use lithium batteries for 50%-70% of their batteries will increase the demand for lithium-ion batteries year by y...

AI Technical Summary

Problems solved by technology

Studies have shown that when the thickness of the film is large, new crystals will be formed during the lithium intercalation process, thereby reducing the reversible capacity; reducing the thickness of the silicon film can alleviate the volume expansion effect, but reduce the quality of the electrode active material and lithium storage capacity

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