FexSnyMn1-x-yO2 deposited on MCM-41 as electrode for electrochemical supercapacitor

To enhance the specific capacitance, cycling stability and material utilization of manganese dioxide (MnO2) for supercapacitor, MCM-41 (mesoporous silica) was firstly synthesized by hydrothermal method, and then FexSnyMn1-x-yO2 layer deposited on MCM-41 was formed through coprecipitation of MnCO3, SnCl4 and FeCl3, followed by calcination to finally obtain FexSnyMn1-x-yO2@MCM-41 electrodes (FS-MnO2@M electrodes). The structure and composition of FS-MnO2@M electrodes were characterized by using scanning electron microscope (SEM), transmission electron microscope (TEM), nitrogen adsorption (BET), Fourier transform infrared spectroscopy (FT-IR) and X-Ray diffraction spectroscopy (XRD). These results of characterization about FS-MnO2@M particles show FS-MnO2 coatings are successfully deposited on the surface of MCM-41and the average coating thickness of FS-MnO2 is around 50 nm. The electrochemical performances of FS-MnO2@M electrodes are evaluated and researched by galvanostatic charge-discharge test, cyclic voltammogram (CV) and electrochemical impedance spectroscopy (EIS). The results show that FS-MnO2@M electrodes with porous structure display superior cycling stability at large current work condition in charge-discharge tests and good capacitance performance at high scanning rate in CV tests and FS-MnO2@M electrodes indicate the smaller internal resistance through EIS. And the specific capacitance of FS-MnO2@M reaches 319 F g−1 at current density of 2 A g−1 with the value remaining 88.37% after 10000 cycles. Therefore, the FS-MnO2@M electrode is desirable to become a novel MnO2 electrode for electrochemical supercapacitor.