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.