High performance hierarchical porous carbon derived from waste shrimp shell for supercapacitor electrodes

Biomass-derived porous carbons have been evoking the scientists' enthusiasm as electrode materials for energy storage devices owing to their abundance and sustainability, low cost, superior electrical conductivity, tunable surface chemistry, high specific surface area, as well as superb electrochemical stability. Here, honeycomb-like hierarchical porous carbons are successfully prepared via a facile self-template coupled dual-hydroxide (NaOH/KOH) activation strategy using mantis shrimp shell waste as precursor. The as-prepared MSHPC1.5–800 possesses a high specific surface area (2465.9 m2 g−1), high micropore volume/total pore volume ratio (52.71 %). The as-assembled symmetric supercapacitors exhibit a high specific capacitance (300.3 F g−1/0.05 A g−1). Under 20 A g−1, the specific capacitance reached up to 220.2 F g−1. The symmetrical supercapacitors also display an excellent cycling stability with 96.7 % capacitance retention over 10,000 cycles at 5 A g−1. Moreover, the as-fabricated aqueous zinc-ion hybrid supercapacitors (ZHSs) deliver a high specific capacitance of 108.5 mAh g−1 (0.05 A g−1), superior energy density of 97.4 Wh kg−1 (19.6 W kg−1), ultralong cycling lifespan with 79.82 % capacitance retention and outstanding Coulombic efficiency of ~100 % after 50,000 cycles. This paper affords a feasible approach to obtain biomass-based carbon materials for high-performance supercapacitor.