Shrimp shell-derived N, O-doped honeycomb-carbon for high-performance supercapacitor

Electrochemical capacitors (ECs) have garnered gargantuan attention by virtue of their eminent features, such as admirable power density, infinite cycling stability, and fast charging/discharging rates. Herein, shrimp shell-derived honeycomb-carbons were scrupulously obtained via a molten-salt activation strategy, with the aim of developing advanced electrode materials for supercapacitors. The optimized sample exhibited a high specific surface area, expedient pore volume, and high nitrogen/oxygen content. Consequently, the as-assembled symmetric supercapacitor delivered a high specific capacitance of 218 F g−1 at 0.05 A g−1 and excellent cycling stability with 94.15 % capacitance retention over 10,000 cycles. More importantly, the as-constructed SS-0.7|2M ZnSO4|Zn foil zinc-ion hybrid supercapacitor (ZHS) displayed remarkable specific capacitance (109.6 mAh g−1) at 0.05 A g−1, superior energy density (87.56 Wh kg−1) at 36.87 W kg−1, along with unparalleled cycling performance (with only 4.19 % capacitance decay after 50,000 cycles). This work provides a new perspective on engineering honeycomb-like hierarchical porous carbon for application in supercapacitors. [Display omitted] •The obtained porous carbon exhibited high SSA, applicable PSD and oxygen doping.•The influence of KCl to K2CO3 mass ratio to honeycomb-like carbon was discussed.•The optimum electrode delivered excellent performance for EDLCs and ZHSs devices.