Biomass-derived hierarchical porous carbon/silicon carbide composite for electrochemical supercapacitor

Hierarchical porous carbon/ silicon carbide composite (HPC/SiC) was fabricated directly from raw biomass via a facile method, in which the wasted villi of bamboo shoot shell (VBSS) and KOH were employed as green carbon source and chemical etching agent, respectively. Owing to the large surface area and developed porous texture originating from carbon and the favorable conductivity resulting from SiC, the obtained HPC/SiC exhibits a specific capacitance of 234.2 F g-1 at the current density of 1 A g-1, a remarkable rate capability of 71.4% at 20 A g-1 and a prominent cycling performance with 90.8% retention after 10,000 cycles. The assembled symmetric device demonstrates a 224 F g-1 specific capacitance at a current density of 0.2 A g-1. The high energy densities of 25.20 W h kg-1 and 17.44 W h kg-1 with corresponding power densities of 181.1 W kg-1 and 17.94 kW kg-1 have been obtained, respectively. This work not only demonstrates that SiC can be formed in the wasted VBSS under mild natural condition for the first time, but also open up new opportunities for the rational design of more efficient biomass-based materials for supercapacitors.