Highly Reversible Zinc Anode Enhanced by Ultrathin MnO2 Cathode Material Film for High-Performance Zinc-Ion Batteries

Zinc-ion batteries (ZIBs) have attracted considerable attention and global interest due to their high gravimetric and high volumetric capacities (820 mAh g(-1) and 5855 mAh cm(-3)). However, the Zn protrusions/dendrites during the plating/stripping process of Zn (Zn2+) severely affect the performance of Zn anode, causing a low Coulombic efficiency, rapid degradation of capacity, and even failure of Zn-anode-based batteries. In order to reduce the dendritic deposition of Zn, the key is to adjust the initial uniform nucleation, which determines the subsequent uniform deposition of Zn. Herein, a cathode material (MnO2) ultrathin film is first modified on the surface of the carbon cloth as active sites for the in situ nucleation and directed epitaxial growth of metal Zn. As a result, the CC@MnO2-UTF@Zn anode can be cycled in aqueous electrolyte and maintain stable cycling performance during repeated Zn deposition/stripping processes. Subsequently, the CC@MnO2-UTF@Zn anode and CC@MnO2 cathode are assembled into full cells, which deliver a superior electrochemical performance. Moreover, the flexible solid-state ZIBs with the CC@MnO2-UTF@Zn anode show excellent capacities and high energy/power densities, which is superior to the most reported results so far. This work provides a new strategy to design an advanced flexibility Zn anode toward future high-performance wearable electronic ZIBs.