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® 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.

► Two polymer electrolyte-based electrochemical capacitors were studied at high rate.
► Both SiWA-H3PO4-PVA and Nafion® were able to perform at 5000 V s− 1 initially.
► SiWA-H3PO4-PVA polymer electrolyte showed a much better shelf life than Nafion®.
► A thin two-cell/single-package capacitor using SiWA-H3PO4-PVA was demonstrated.