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

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 KHCO3 and Na2S2O3. Accordingly, NSPCK achieves high capacitance (262.7 F g−1) and long cycle life (remains 99.3% after 10,000 cycles) in 1 M Zn(CF3SO3)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.