Electrochemical Performance of Nickel Hydroxide/Activated Carbon Supercapacitors Using a Modified Polyvinyl Alcohol Based Alkaline Polymer Electrolyte

Abstract

Polyvinyl alcohol (PVA)-sodium polyacrylate (PAAS)-KOH-H 2O alkaline polymer electrolyte film withhigh ionic conductivity was prepared by a solution-casting method. Polymer Ni(OH) 2/activated carbon (AC) hybridsupercapacitors with different electrode active material mass ratios (positive to negative) were fabricated using this alkaline polymer electrolyte, nickel hydroxide positive electrodes, and AC negative electrodes. Galvanostatic charge/discharge and electrochemical impedance spectroscopy (EIS) methods were used to study the electrochemical performance of the capacitors, such as charge/discharge specific capacitance, rate charge/discharge ability, and charge/discharge cyclic stability. Experimental results showed that with the decreasing of active material mass ratio m(Ni(OH) 2)/ m(AC), the charge/discharge specific capacitance increases, but the rate charge/discharge ability andthe charge/discharge cyclic stability decrease.