| Since Ni-MH batteries were mass-produced and put into commercial use in the1990s,the development of hydrogen storage al oy electrode material as the negative electrode of Ni-MH battery has made remarkable progress.However,with the rapid development of electric vehicles and energy storage devices,traditional Ni-MH batteries are still relatively slow to improve the energy density due to the shortcomings of the capacity of hydrogen storage al oy electrodes and the narrow electrochemica l window of aqueous electrolyte,which greatly limits the further application of Ni-MH batteries.Therefore,under the trend of the government's strong support for the development of the hydrogen energy industry,it is significant for the continued development of nickel-metal hydride batteries by looking for a new type of high-capacity hydrogen storage material to replace the traditional hydrogen storage aloy as the anode of the nickel-hydrogen battery,which matched with an electrolyte with a wide electrochemical window.Based on recent preliminary research results on the reversible electrochemical hydrogen storage properties of amorphous silicon?a-Si?materials,this paper firstly investigated the fabrication process of amorphous silicon thin films by magnetron sputtering.The amorphous silicon thin films were characterized by three-dimensional contour,XRD?XPS?EDS?TEM and other characterization methods.The above a-Si films were hydrogenated in high purity H2 at a certain pressure and temperature to prepare hydrogenated amorphous silicon?a-Si:H?films.the structure and silicon-hydrogen bonding mode of the a-Si:H films were analyzed by FT-IR spectroscopy.Finally,the proton-type ionic liquid composed of 1-ethyl-3-methylimidazole acetate ionic liquid?[EMIM][Ac]?mixed with acetic acid was used as the electrolyte,and amorphous silicon film and hydrogenated amorphous silicon film were used as the negative electrode of the battery,respectively,to assemble the Swagelok type battery,the electrochemical properties of the above a-Si and a-Si:H films were tested and analyzed.The main results are as follows:?1?In the process of magnetron sputtering,the sputtering power and gas working pressure have obvious influence on the growth of amorphous silicon films.With the increase of sputtering power,the growth rate of the film increases;the action of the working pressure is opposite,and the growth rate of the film decreases with the increase of the working pressure.According to the related characterization,the amorphous silicon film appears.Due to the restriction of experimental conditions,there is a certain degree of oxidation on the surface and in the bulk phase of the amorphous silicon film,and in the sputtering process,there are silicon nickel compounds at the interface between the substrate and the film.?2?Hydrogenation of amorphous silicon films was carried out by hydrogen storage performance PCT device.In the process of high temperature hydrogenation,the film spalling appears,and with the extension of hydrogenation time,the spalling phenomenon intensifies,and the pores appear on the film surface.In addition,it was found that some of the films were crystallized after high temperature hydrogenation,and the oxidation of the films was more obvious.By infrared spectroscopy analysis,there SiH,SiH2,SiH3 three bonding modes in the hydrogenated amorphous silicon films.?3?In electrochemical tests,the charge/discharge current density is set to 200mA·g-1,the intrinsic amorphous silicon film has a maximum discharge capacity of 113mAh·g-1,and the amorphous silicon film with al oy prepared by co-sputtering has a maximum discharge capacity of 221 mAh·g-1,which indicated that the electrical conductivity has effect on the electrochemical performance of amorphous silicon.The hydrogenated amorphous silicon film has a maximum discharge capacity of 479.5mAh·g-1,which indicates that the effect of the hydrogenation is more obvious for the electrochemical performance.This shows that amorphous silicon has great potential in Ni-MH batteries. |
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