초록 |
The development of the asymmetric supercapacitor with high power and energy density is an important challenge to meet the requirements of advanced electronic gadgets. However, the present asymmetric supercapacitors have lower energy density due to the carbon based negative electrode. To overcome this issue, the various transition metal oxides with high theoretical capacitance have been investigated for negative electrode materials. With this motivation, we assembled the asymmetric supercapacitor device using WO3 (5.8 mg/cm2) and MnO2 (4.9 mg/cm2) as negative and positive electrode material, respectively. Both electrodes show excellent electrochemical performance in the negative and the positive potential in Na2SO4 electrolyte. The fabricated asymmetric supercapacitor device has the operating voltage of 1.4 V and excellent cycling stability (~135 %, after 7500 cycles) and rate stability. Furthermore, the optimized asymmetric device displays the volumetric capacitance of 350 mF/cm3 and energy density of 95.28 mWh/cm3. |