3D MXene/PVA Aerogel Enabling a Dendrite-Free Zn Metal Anode.

Aqueous zinc-ion batteries have attracted widespread attention due to their low cost and high safety. Unfortunately, their commercial applications are greatly inhibited by the negative effects of zinc dendrites and side reactions. A solution that utilizes a 3D host can help mitigate these issues. In this paper, we present a 3D host that is composed of an aerogel scaffold with a poly(vinyl alcohol) and MXene structure. The embedded Zn can be densely packed inside the host due to its zincophilic properties. During cycling, the fluorine-based functional groups on the surface of MXene were able to react with the electrolyte to form the ZnF solid electrolyte interphase, which can effectively protect the composite anode. As a result, the symmetrical battery was capable of stable cycling for >300 h at a high current density of 10 mA cm. More impressively, the assembled full cell retained 93.86% after 800 cycles at a current density of 5 A g. This work provides an effective idea for improving the cycling performance of aqueous zinc-ion batteries.