Preparation method and application of supercapacitor electrode film

The invention discloses a preparation method of a supercapacitor electrode film, which comprises the following steps of: performing chemical in-situ etching on a monocrystalline silicon substrate to obtain a nanowire silicon substrate, and preparing a Cr-doped TiN film on the nanowire silicon substrate by adopting magnetron sputtering to obtain the supercapacitor electrode film. The chemical in-situ etching method and the magnetron sputtering method are combined, the nanowire silicon substrate is formed through chemical in-situ etching, nanocrystallization of the silicon substrate structure is achieved, the specific surface area of the electrode is increased, Cr doping is conducted on the TiN film deposited on the nanowire silicon substrate through the magnetron sputtering method, the surface activity of the electrode is improved, and through the combined action of the two methods, the specific surface area of the electrode is increased. The energy density of the electrode film is improved, the electrochemica