Stress‐Release Functional Liquid Metal‐MXene Layers toward Dendrite‐Free Zinc Metal Anodes

Zinc anodes are promising for zinc-based batteries owing to the high theoretical capacity (820 mAh g−1), environmental-friendliness, and good safety, but the uncontrollable dendrites greatly hamper their practical applications. Here, a special nonmodulus liquid GaIn electrode is designed to help understand the failure mechanism of Zn anodes, demonstrating that there is a huge crystalline stress in the plating Zn anode that causes the fast growth of substantial Zn dendrites. To solve this issue, a zinc-enriched liquid metal (ZnGaIn) anode on flexible MXene layers (ZnGaIn//MXene) is fabricated, enabling efficient release of the stress in the plating Zn anode. Moreover, owing to the presence of zinc-based liquid metal, the nucleation energy barrier is largely reduced and meanwhile the nucleation overpotential of Zn is reduced to 0 V versus Zn2+/Zn. Thus, the as-prepared flexible zinc-based anode delivers a long cycle life and high rate capabilities up to 8.0 mA cm−2. As coupled with a MnO2 cathode, a full cell with ZnGaIn//MXene anode exhibits a stable and long lifespan, greatly benefiting the development of next-generation zinc-based batteries.