An aqueous zinc-ion hybrid super-capacitor for achieving ultrahigh-volumetric energy density

• 作 者: Li Zhang Dandan Wu Gaowei Wang Yongtai Xu Hongxia Li Xingbin Yan
• 机 构: Department of Physics, School of Science, Lanzhou University of Technology, Lanzhou 730050, China;La
• 出 处: 中国化学快报（英文版）
• 发表日期: 2021年2期
• 关键词: Zinc-ion hybrid super-capacitors Volumetric energy density Dense three-dimension

Zinc-ion hybrid super-capacitors are regarded as promising safe energy storage systems.However,the relatively low volumetric energy density has become the main bottlenecks in practical applications of portable electronic devices.In this work,the zinc-ion hybrid super-capacitor with high volumetric energy density and superb cycle stability had been constructed which employing the high-density threedimensional graphene hydrogel as cathode and Zn foil used as anode in 1 mol/L ZnSO4 electrolyte.Benefiting from the abundant ion transport paths and the abundant active sites for graphene hydrogel with high density and porous structure,the zinc-ion hybrid super-capacitor exhibited an extremely high volumetric energy density of 118.42 Wh/L and a superb power density of 24.00 kW/L,as well as an excellent long cycle life (80％ retention after 30,000 cycles at 10 A/g),which was superior to the volumetric energy density of the reported zinc-ion hybrid super-capacitors.This device,based on the fast ion adsorption/desorption on the capacitor-type graphene cathode and reversible Zn2+ plating/stripping on the battery-type Zn anode,which will inspire the development of zinc-ion hybrid super-capacitor in miniaturized devices.