A new electrode material, carbon aerogel supported manganese dioxide (AG-MnO₂) has been prepared. Psychochemical and electrochemical characterizations indicated that the electrochemical performance of carbon aerogel can be dramatically improved only through depositing manganese dioxide on its surface. A novel hybrid supercapacitor using AG-MnO₂ and LiMn₂O₄ as negative and positive electrodes has been developed. The effect of operating potential window of negative electrode on the performance of the hybrid supercapacitor has also been investigated in this paper. The results showed that combined high capacitance AG-MnO₂ material with a wide operating potential window of the negative electrode, the energy density of hybrid supercapacitor can reach to 92 Wh•kg^－1 (based on active material mass of positive and negative electrodes), almost five times higher than that of carbon supercapacitor. After 1000 cycles, the capacitance of this new hybrid supercapacitor still remained above 80% of original value.

Key words: manganese dioxide, carbon material, composite, hybrid supercapacitor