Graphene/SiC composite porous electrodes for high-performance micro-supercapacitors

Micro-supercapacitor (MSC) electrodes prepared by chemical vapor deposition (CVD) possess high potential as on-chip integrated micro-power sources for future microdevices. In this study, porous graphene/SiC composite films are grown using laser CVD. A double-layer specific capacitance up to 219.3 mF/cm2 is achieved at 10 mV/s, which is 26 times higher than those of the electrodes prepared by CVD with the same energy storage mechanism reported in literatures. After 20000 charge-discharge cycles at room temperature (20 degrees C) and variable temperatures (0-60 degrees C), the electrode exhibits robust cycling stability with 99.9% and 109.6% capacitance retention, respectively. Subsequently, it is revealed that the abundance of graphene on the SiC porous skeleton plays a key role in promoting the capacitance enhancement. The strong structure of SiC as well as the strong adhesion between graphene and SiC guarantee the excellent cycling stability. Evidently, the preparation of graphene/SiC porous composite films as MSC electrodes is a highly promising route for fabricating high-performance and reliable on-chip power sources for future miniaturized devices.