Mechanochemical-synthesized Al-doped manganese dioxides for electrochemical supercapacitors

Al-doped MnO2 as electrode materials for supercapacitor were synthesized by high-energy ball milling. The morphologies and structures of prepared MnO2 were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Electrochemical investigation indicated that doped MnO2 presented preferable electrochemical performances than un-doped MnO2, but there were obvious capacitance decline in the first several dozen of cycles for all doped MnO2 samples. The Al-0.05/Mn0.95O2 electrode, especially, showed the largest capacitance among all prepared MnO2 samples. Excellent conductivity of Al in doped MnO2 was considered to be responsible for enhanced electrochemical performances of doped MnO2.