초 록o C for 5 h had larger first discharge capacity (41.5 mAh/g) at 1C-rate for 3.7~4.4 V than other calcined samples. Moreover, applying to hybrid capacitor, it had good discharge capacity (24.74 mAh/g or 10.46 mAh/cc) at 100 mA/g for 1~2.5 V and higher energy density (39 Wh/kg or 16.49 Wh/cc) at same condition.

:In order to apply hybrid capacitor, Li 2 Mn 3 O 7 was synthesized by combustion method using LiNO 3 , Li(CH 3 COO)·2H 2 O and Mn(CH 3 COO) 2 ·4H 2 O. Spinel pattern was identified the samples calcined over 400 o C in XRD. Intensity of Mn 2 O 3 peak increased as the calcination temperature increased. To decide n/p ratio and to investigate electrochemical properties, charge-discharge tests of Li/ Li 2 Mn 3 O 7 and Li/AC half-cell were carried out. Applying to AC/Li 2 Mn 3 O 7 hybrid capacitor, it had high discharge capacitance of 32.8 F/cc at 100 mA/g.