A comparative study of polymer electrolytes for ultrahigh rate applications

A solid-polymer electrolyte, composed of silicotungstic acid (SiWA), orthophosphoric acid (H3PO4), and polyvinyl alcohol (PVA), was studied and compared with Nafion (R) in an electrochemical capacitor (EC) device under ambient conditions. While initially both solid-polymer electrolyte based ECs demonstrated exceptionally high rate capability (5000 Vs(-1) and a 0.05 ms time constant), the SiWA-based device showed a much better shelf life than the Nafion-based device. In addition, a thin two-cell, single-package EC utilizing the SiWA-based solid-polymer electrolyte was demonstrated and showed excellent rate capability and shelf life. (C) 2012 Elsevier B.V. All rights reserved.