Porous Carbon Prepared Via Combustion and Acid Treatment As Flexible Zinc-Ion Capacitor Electrode Material

•Oxygen-enriched porous carbon (OPC) is rationally designed as electrode material.•Gelatin gel is applied as electrolyte for zinc-ion hybrid capacitor (ZIC).•The assembled capacitor displays high specific capacitance of 132.7 mA h g−1.•The assembled solid-state ZIC is flexible enough to withstand various deformations.•The electrochemical kinetic of OPC electrode in ZIC is analyzed.