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

The Sn-doped [Formula: see text]-MnO 2 (Sn–MnO 2 ) hollow structures was successfully prepared via a chemical process at room temperature (25[Formula: see text]C). Compared to pure MnO 2 , Sn–MnO 2 shows an obviously enhanced capacitance and outstanding cycling performance at high operating temperature of 85[Formula: see text]C. For Sn–MnO 2 , the specific capacitance ([Formula: see text]) of 169.9[Formula: see text]Fg[Formula: see text] at current density of 1[Formula: see text]Ag[Formula: see text] was measured at 85[Formula: see text]C and retains over 90% of its initial capacitance after 1000 cycles. Meanwhile, the electrochemical properties of Sn–MnO 2 were investigated on different temperatures (25[Formula: see text]C, 45[Formula: see text]C, 65[Formula: see text]C and 85[Formula: see text]C), and an improved capacitive performance was obtained with the temperature increasing.