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Zinc-ion hybrid supercapacitors (ZHSCs) are attracting significant attention due to their high energies/power densities, safety, and low cost. In this review, recent advances in the development of ZHSCs are summarized. Particular emphasis is placed on state-of-the-art cathodes (including carbon, metal oxides, MXenes, and redox-active polymers), anodes (including Zn-based composites and Zn-free materials) and electrolytes for ZHSCs. Furthermore, the latest research on functional ZHSC devices with miniaturized ZHSCs, fiber-shaped ZHSCs, self-chargeable ZHSCs and self-healing devices is reported. Finally, further developments with ZHSCs are envisaged for future research in this thriving field. This research is emphasized particularly on cathodes (such as carbon, metal oxides, MXenes, and redox-active polymers), anodes (such as Zn-based composite materials and Zn-free materials), electrolytes (organic/ionic liquid electrolytes, WiSs, redox electrolytes, polymer or solid electrolytes) as well as the design of a novel device for ZHSCs. [ABSTRACT FROM AUTHOR]

Metallic lithium is regarded as one of the most promising electrode materials to break through the energy density bottleneck of current commercial lithium-ion batteries. However, the practical implementation of lithium metal anode is limited by the unstable electrode interface significantly, which directly induces a low Coulombic efficiency, short cycling lifespan, and dendritic lithium growth behavior. In this study, via in situ electropolymerization, lithiophilic and conformal polyaniline layer is developed to improve the initial lithium nucleation and plating process, reducing the interface charge transfer resistance and promoting uniform lithium plating/stripping behavior. Meanwhile, the polyaniline layer exhibits good adhesion to the substrate. As a result, the Li/Cu half cell delivers a high Coulombic efficiency of 99.1% for 400 cycles at 1.0 mA·cm−2 with polyaniline layer. In addition, long-term stable cycling at a current density of 1.0 mA·cm−2 for 1300 h has been achieved for lithium metal anode. This strategy provides a new perspective for the practical lithium metal batteries. [ABSTRACT FROM AUTHOR]

Lithium (Li) metal anode has received extensive attentions due to its ultrahigh theoretical capacity and the most negative electrode potential. However, dendrite growth severely impedes the practical applications of the Li metal anode in rechargeable batteries. In this contribution, a mesoporous graphene with a high specific surface area was synthesized to host the Li metal anode. The mesoporous graphene host (MGH) has a high specific surface area (2090 m2/g), which affords free space and an interconnected conductive pathway for Li plating and stripping, thus alleviating the volume variation and reducing the generation of dead Li during repeated cycles. More importantly, the high specific surface area of MGH efficiently reduces the local current density of the electrode, which favors a uniform Li nucleation and plating behavior, rendering a dendrite-free deposition morphology at a low overpotential. These factors synergistically boost the Li utilization (90.1% vs. 70.1% for Cu foil) and life span (150 cycles vs. 100 cycles for Cu foil) with a low polarization of MGH electrode at an ultrahigh current of 15.0 mA/cm2. The as-prepared MGH can provide fresh insights into the electrode design of the Li metal anode operating at high rates. [ABSTRACT FROM AUTHOR]