Microzone-explosion synthesis of porous carbon electrodes for advanced aqueous solid-state supercapacitors with a high-voltage gel electrolyte

Abstract A new microzone-combustion synthesis is proposed for preparing S, N-doped hierarchically porous carbons (CAC-CN) with a novel mixed microstructure of sp2 short-range order area and sp3 defective area, achieving a coexistence of high conductivity and high capacitance as well as good access for electrolyte. By engineering “water in salts” into a polymer matrix, a high-voltage (2.5 V) aqueous gel electrolyte (HG-WIS) is prepared and used to construct an aqueous solid-state SCs by in situ polymerization between the electrodes. The good match of CAC-CN electrode and HG-WIS electrolyte endows the assembled devices with superior high energy density and excellent capacitance retention, also a good temperature robustness, as well a high flexibility in 0-180° bending cycles. This study indicates that the collaborative design strategy of electrode materials and electrolyte would be great potential in exploring advanced aqueous solid-state SCs.