Layer-by-layer zinc metal anodes to achieve long-life zinc-ion batteries

Aqueous rechargeable zinc-ion batteries have attracted much attention due to high safety, fast charge/discharge rate, low cost and direct utilization of zinc metal anodes. However, zinc anodes suffer from fundamental issues and elusiveness of critical information such as its nucleation and plating/stripping behaviors. Herein, we explore nucleation pattern of zinc on various metal substrates (Cu, Ag, Ti or Sn) and discover a substrate-dependent plating/stripping behavior. With use of binary diagrams (Ag|Cu, Ti|Cu and Cu|Sn), we found that zinc has a selective deposition on Cu substrates with no nucleation barriers. Theoretical calculation also indicates a relatively low bonding energy between Zn and Cu. Besides, it is also found that Sn inhibits growth of by-product of basic zinc sulfates. Thereafter, we report a layer-by-layer construction of zinc metal (Sn/Cu/Zn) anode for long-life zinc-ion batteries. Our work paves a way to understand plating/stripping behavior of metal anodes and to design layer-by-layer metal anodes for metal batteries.