Metal-organic framework ZIF-8-derived Zn/N Co-doped porous carbon for high-performance zinc-ion capacitors

Aqueous zinc-ion capacitors offer several advantages, including enhanced power density and safety, low cost. However, the energy density of zinc-ion capacitors is still constrained by the energy storage capacity of cathode materials. In this study, we synthesized a zinc/nitrogen co-doped porous carbon material by utilizing an organometallic polymer as precursor and nano-silica as pore forming additive. Impressively, the analysis results reveal that prepared carbon material is equipped with the uniform distribution of Zn/N atoms, splendid specific surface area (2226.1 m² g⁻¹) and homogeneous porous architecture. The incorporation of Zn/N atoms and abundant pores enhance the ion adsorption sites of carbon materials, while also facilitating the diffusion of zinc ions. Thus, the Zn/N co-doped porous carbon as cathode material for zinc-ion capacitors delivers significantly enhanced electrochemical performance compared with the contrast sample. The dynamic behavior analysis further demonstrates that porous structures play a crucial role in activating the electrochemical performance of carbon materials. This work represents a fundamental approach for the development of cathode materials with superior electrochemical properties for zinc-ion capacitors.