Electrochemical capacitor behavior of SO42-/MxOy (M-Fe, Ti, Zr, Sn)

SO42−/MxOy (M-Zr, Ti, Sn, Fe) system has been investigated as a potential electrode material for supercapacitors. It is precipitated as metal oxide gel by alkaline hydrolysis of metal precursor, and subsequently impregnated with sulfuric acid and calcined. The SO42−/MxOy is characterized by X-ray diffraction, Fourier-transform infrared and an electrochemical analyzer system. The specific capacitance of SO42−/MxOy is higher than the value of MxOy at the same scan rate. SO42-/MxOy displays a good retention for more than 500 cycles in a cycling test. The experimental results and the thorough analyses described in this work not only provide a potential electrode material for supercapacitors but also give us a new application of the solid super acid.