Uniform distribution of zinc ions achieved by functional supramolecules for stable zinc metal anode with long cycling lifespan

Abstract

Zinc (Zn) metal anode, as a promising candidate for high-energy Zn-based batteries, is attracting more attention for its high specific capacity and safety. However, severe issues of uncontrollable side reactions and fatal Zn dendrites exhibit great limitations for practical application. Herein, a unique separator decorated with functional supramolecules (GF@SM) is constructed for guiding the uniform distribution of Zn ions and enhancing the electrochemical performance of the Zn metal anode. Plenty of zincophilic groups in supramolecules display a superior affinity with Zn ions, avoiding the accumulation of Zn ions on the electrode surface and suppressing the formation of dendritic Zn metal. When applied in the Zn metal batteries, GF@SM separators can effectively improve electrochemical performances. For the galvanostatic charging/discharging test, an ultralong lifespan of 2000 h with stable voltage polarization can be delivered by the symmetric cell with GF@SM. Zn|MnO2 full cell based on GF@SM composite separator exhibit a stable and high specific capacity of 159.8 mAh g−1 after 1000 cycles at 1 A g−1 and superior rate capability. The unusual design of this composite separator and its promising application provides helpful guidance for safe and high-performance Zn metal batteries.