Microsupercapacitors Working at 250 °C

Abstract

AbstractThe raised demand for portable electronics in high‐temperature environments (>150 °C) stimulates the search for solutions to release the temperature constraints of power supply. All‐solid‐state microsupercapacitors (MSCs) are envisioned as promising on‐chip power supply components, but at present, nearly none of them can work at temperature over 200 °C, mainly restricted by the electrolytes which possess either low thermal stability or incompatible fabrication process with on‐chip integration. In this work, we have developed a novel process to fabricate highly thermally stable ionic liquid/ceramic composite electrolytes for on‐chip integrated MSCs. Remarkably, the electrolytes enable MSCs with graphene‐based electrodes to operate at temperatures as high as 250 °C with a high areal capacitance (~72 mF cm−2 at 5 mV s−1) and good cycling stability (70 % capacitance retention after 1000 cycles at 1.4 mA cm−2).