High-performance tin-oxide supercapacitors using hydrazine functionalising assisted by hydrogen plasma treatment

For the first time, the effects of adding hydrazine solution to tin-oxide sol-gel to be used as an electrode in high-performance supercapacitors have been studied. The mixed solution has been spin-coated on stainless steel foils as substrates followed by exposing to hydrogen plasma treatment. The results show the effectiveness of adding hydrazine to tin-oxide sol-gel, compared to pure tin-oxide sol-gel. The electrochemical tests such as cyclic-voltammetry and charge-discharge characteristics have been conducted, and the findings demonstrate the favourable contribution of adding hydrazine in increasing the capacitance of the supercapacitor. The physical properties of the tin-oxide material have been analysed by means of FESEM, XRD, TEM, FT-IR spectroscopy and Raman spectroscopy to have a better understanding of preparation procedure and better insight in material synthesis. The electrochemical tests demonstrate a high capacitance of 18 mF/cm(2) for the sample treated with hydrazine during the sol-gel processing which is around 40% higher than the merely prepared tin-oxide sample. The measured values for the capacitance versus rate show a rather linear correlation between these parameters, further corroborating an electric-double layer-based performance for such devices.