Tannin-Derived Ordered Mesoporous Carbon Cathode for Zn-Ion Hybrid Supercapacitor with Remarkable Energy Density

Zn-ion hybrid supercapacitors (ZHSCs) have been considered as a promising candidate for energy storage systems because of the merits they inherited from both supercapacitors and rechargeable batteries. Herein, we show the eco-friendly modified solvent evaporation-induced self-assembly (EISA) synthesis of newly engineered plant polyphenol tannin-derived ordered mesoporous carbons (TOMCs) and employ them as cathode material for high-performance ZHSCs to promote the diffusion dynamics of Zn2+ ions for the first time. The optimized TOMC-700 possesses a high Brunauer–Emmett–Teller (BET) surface area of 967 m2 g–1, narrow mesopores centered at ∼3.5 nm, and rich heteroatoms. Profiting from the synergy of enhanced kinetics and electroactivity, the aqueous TOMC-700-based ZHSC exhibits intriguing Zn-storage capabilities, including a superior energy density of 148.9 Wh kg–1 at 180 W kg–1 in a broad potential range of 0–1.8 V and long-term cycling stability. Moreover, the quasi-solid TOMC-700-based ZHSC also delivers an outstanding energy density of 121.3 Wh kg–1 at 180 W kg–1. These results highlight the facile fabrication of a natural carbohydrate-derived ordered mesoporous carbon as cathode material, notably boosting the development of Zn-based hybrid energy storage systems.