Effects of Sn doping on capacitive performance of σ-MnO2 on the high operating temperatures

The Sn-doped σ-MnO2 (Sn–MnO2) hollow structures was successfully prepared via a chemical process at room temperature (25∘C). Compared to pure MnO2, Sn–MnO2 shows an obviously enhanced capacitance and outstanding cycling performance at high operating temperature of 85∘C. For Sn–MnO2, the specific capacitance (Cs) of 169.9Fg−1 at current density of 1Ag−1 was measured at 85∘C and retains over 90% of its initial capacitance after 1000 cycles. Meanwhile, the electrochemical properties of Sn–MnO2 were investigated on different temperatures (25∘C, 45∘C, 65∘C and 85∘C), and an improved capacitive performance was obtained with the temperature increasing.