High-Power Energy Storage Device of Hybrid Type Electrochemical Capacitor with Asymmetric Electrodes of Ni(OH)_2 and Activated Carbon

摘要

A hybrid type of electrochemical capacitor with asymmetric electrodes was studied. Characteristics of the hybrid capacitor having both the electric double layer capacitance and pseudo-capacitance were investigated throughout unit-cell tests. Asymmetric electrodes with Ni(OH)_2/activated carbon-based positive electrode and activated carbon-based negative electrode were used along with aqueous electrolyte(KOH). Tested unit-cells were prepared as 5x5 cm~2 of electrodes size. From this study it was found that activated carbons mixed with Ni(OH)_2 in the positive electrode affected on pseudo-capacitance. The hybrid capacitor could be operated up to 1.6V even though in aqueous electrolyte. Maximum specific capacitances of unit-cells were depended on mass ratios of negative to positive electrode material.