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 three-dimensional 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.

锌离子混合超级电容器被认为是有前途的安全储能系统。然而，相对较低的体积能量密度已经成为便携式电子设备的实际应用中的主要瓶颈。本文以1 mol / L ZnSO ₄为溶剂，以高密度三维石墨烯水凝胶为阴极，以锌箔为阳极，构建了具有高体积能量密度和优异循环稳定性的锌离子混合超级电容器。电解质。得益于高密度和多孔结构的石墨烯水凝胶的丰富的离子传输路径和丰富的活性位点，锌离子混合超级电容器具有118.42 Wh / L的极高体积能密度和24.00 kW的超高功率密度/ L，以及出色的长循环寿命（在10 A / g的30,000次循环后保留80％），这优于已报道的锌离子混合超级电容器的体积能量密度。该装置基于电容器型石墨烯阴极上的快速离子吸附/解吸和电池型Zn阳极上可逆的Zn ²⁺镀/剥离，将激发小型设备中锌离子混合超级电容器的发展。 。