High-temperature supercapacitor with a proton-conducting metal pyrophosphate electrolyte

Takashi Hibino; Kazuyo Kobayashi; Masahiro Nagao; Shinji Kawasaki

doi:10.1038/srep07903

High-temperature supercapacitor with a proton-conducting metal pyrophosphate electrolyte

Sci Rep. 2015 Jan 20:5:7903. doi: 10.1038/srep07903.

Authors

Takashi Hibino¹, Kazuyo Kobayashi¹, Masahiro Nagao¹, Shinji Kawasaki²

Affiliations

¹ Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
² Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan.

Abstract

Expanding the range of supercapacitor operation to temperatures above 100 °C is important because this would enable capacitors to operate under the severe conditions required for next-generation energy storage devices. In this study, we address this challenge by the fabrication of a solid-state supercapacitor with a proton-conducting Sn(0.95)Al(0.05)H(0.05)P(2)O(7) (SAPO)-polytetrafluoroethylene (PTFE) composite electrolyte and a highly condensed H3PO4 electrode ionomer. At a temperature of 200 °C, the SAPO-PTFE electrolyte exhibits a high proton conductivity of 0.02 S cm(-1) and a wide withstanding voltage range of ± 2 V. The H3PO4 ionomer also has good wettability with micropore-rich activated carbon, which realizes a capacitance of 210 F g(-1) at 200 °C. The resulting supercapacitor exhibits an energy density of 32 Wh kg(-1) at 3 A g(-1) and stable cyclability after 7000 cycles from room temperature to 150 °C.