A Thin and Uniform Fluoride-Based Artificial Interphase for the Zinc Metal Anode Enabling Reversible Zn/MnO₂ Batteries

Zn batteries have recently become of great interest as energy storage devices. However, their lifespan is limited by irreversible processes at the Zn anodes owing to side reactions and dendrite growth in a mild pH electrolyte. Herein, an artificial ZnF2 layer on the Zn metal anode surface is developed to address these issues. Modeling results suggest that ZnF2 can allow insertion of Zn2+ and offers diffusion channels for the transport to/from the Zn anode via an interstitial diffusion mechanism. The artificial layer suppresses dendrite growth by guiding the Zn plating/stripping underneath the layer, thus enhancing the electrochemical performance of the anode as demonstrated by the Zn-ZnF2/MnO2 full cell. The Zn anode with this artificial layer sustains long-term cycling (more than 700 h) at an areal capacity of 0.5 mAh cm–2, and the Zn-ZnF2/MnO2 full cells achieve a capacity retention of 89% after 3000 cycles.