High-Temperature All Solid-State Microsupercapacitors based on SiC Nanowire Electrode and YSZ Electrolyte

We demonstrate a symmetric supercapacitor by using yttria-stabilized zirconia (YSZ) as the electrolyte and silicon carbide nanowires (SiC NWs) as the electrode. The stacked symmetric SiC NWs/YSZ/SiC NWs supercapacitors exhibit excellent thermal stability and high areal capacitance at temperatures above 300 °C. The supercapacitor functions well at a record high temperature of 450 °C, yielding an areal capacitance of 92 μF cm(-2) at a voltage scan rate of 100 mV s(-1). At this temperature, it is also capable of withstanding current densities up to 50 μA cm(-2), yielding a maximum areal power density of 100 μW cm(-2). Good cycling stability is demonstrated with a capacitance retention of over 60% after 10,000 cycles at the operation temperature of 450 °C and a scan rate of 200 mV s(-1).