N, S co-doped porous carbons with well-developed pores for supercapacitor and zinc ion hybrid capacitor

Abstract

The introduction of heteroatoms into carbon materials is beneficial for enhancing zinc ion storage capability, and thereby obtaining excellent electrochemical performance. Herein, the N, S co-doped porous carbons (NSPCs) with well-developed pores and massive surface area are synthesized from natural biomass by the synergistic activation strategy of KHCO 3 and Na 2 S 2 O 3 . Accordingly, NSPC K achieves high capacitance (262.7 F g −1 ) and long cycle life (remains 99.3% after 10,000 cycles) in 1 M Zn(CF 3 SO 3 ) 2 aqueous electrolyte for supercapacitor. Impressively, the NSPC cathode presents high discharge capacity of 136.3 mAh g −1 in the voltage window of 0–1.8 V, good rate performance (86.5 mA h g −1 at 20 A g −1 ) and high energy density (122.6 W h kg −1 ) for zinc ion hybrid capacitor (ZHC). Besides, the ZHC delivers long-term life with 0.5% damage after 15,000 cycles. This study may facilitate the design of high-energy and safe electrochemical energy storage devices based on the heteroatom doping carbons and aqueous electrolyte. The N, S co-doped porous carbons with well-developed pores and massive surface area are synthesized from natural biomass by the synergistic activation strategy of KHCO 3 and Na 2 S 2 O 3 , displaying high specific capacity and energy density in aqueous two-electrode system. • The N, S co-doping porous carbon (NSPC K ) was prepared by confined pyrolysis method. • The NSPC K presents well-developed pore structures and has a moderate content of N, S. • The NSPC K shows high specific capacity in 1 M Zn(CF 3 SO 3 ) 2 electrolyte. • The NSPC K cathode displays high energy density and superb cycle stability.