Crab shell derived multi-hierarchical carbon materials as a typical recycling of waste for high performance supercapacitors

Abstract The exhausting energy forces us to search for new green energy and develop energy storage and conversion technologies. Supercapacitors with long service life and high power density show broad application prospect. The multi-hierarchical porous carbon materials were prepared using the crab shell, a typical seafood waste, as the precursor, and investigated as supercapacitor electrode materials. The crab shell derived carbon exhibited specific capacitances of 322.5 and 223.4 F g −1 at current densities of 1 and 10 A g −1 respectively, indicating good capacitive performance and rate capability. Additionally, its cyclic performance was impressive with less than 1% capacitance fading over 10000 cycles at 1 A g −1 . The crab shell derived carbon were further used as support to assemble SrFe 12 O 19 for constructing a superior hybrid supercapacitor with the specific capacitance of 690.4 F g −1 at 1 A g −1 , and 401.3 F g −1 even at 10 A g −1 . Furthermore, the crab shell derived carbon/SrFe 12 O 19 composites displayed the exceptional cycling performance over 10000 cycles with 94.5% of capacitance retention, indicating distinguished capacitive performances. Such cheap, green and high-performance electrode composites based on crab shell waste provide good prospects in energy storage applications.