All-Solid-State On-Chip Supercapacitors Based on Free-Standing 4H-SiC Nanowire Arrays

All-solid-state on-chip SiC supercapacitors (SCs) based on free-standing SiC nanowire arrays (NWAs) are reported. In comparison to the widely used technique based on the interdigitated fingers, the present strategy can be much more facile for constructing on-chip SCs devices, which is directly sandwiched with a solid electrolyte layer between two pieces of SiC NWAs film without any substrate. The mass loading of active materials of on-chip SiC SCs can be up to approximate to 5.6 mg cm(-2), and the total device thickness is limited in approximate to 40 mu m. The specific area energy and power densities of the SCs device reach 5.24 mu Wh cm(-2) and 11.2 mW cm(-2), and their specific volume energy and power densities run up to 1.31 mWh cm(-3) and 2.8 W cm(-3), respectively, which are two orders of magnitude higher than those of state-of-the-art SiC-based SCs, and also much higher than those of other solid-state carbon-based SCs ever reported. Furthermore, such on-chip SCs exhibit superior rate capability and robust stability with over 94% capacitance retention after 10 000 cycles at a scan rate of 100 mV s(-1), representing their high performance in all merits.