Alkaline Polymer Electrolytes for Electrochemical Capacitors

Abstract

Polymer electrolytes for electrochemical capacitors in place of liquid electrolytes were developed to prevent issues such as leakage and safety concerns. Currently, there is a lack of available OH--ion conducting polymer electrolytes compared to Li+-ion and H+-ion conducting ones. OH--ion conducting polymer electrolytes with high ionic conductivity and environmental stability in ambient conditions are required. TEAOH-PVA polymer electrolyte, a suitable replacement for KOH-PVA, demonstrated similar pristine ionic conductivities and superior shelf-life in ambient conditions. TEAOH-PVA also revealed the highest ionic conductivity compared to TEAOH-PEO and TEAOH-PAA polymer electrolytes. Optimization of TEAOH-PVA via light cross-linking produced a polymer electrolyte with a high ionic conductivity of 1 x 10-2 S cm-1 and stable shelf-life over a period of 80 days. An EDLC device made with this polymer electrolyte yielded an excellent capacitance of 110 μF at 120 Hz, appropriate for high frequency filtering applications.