Heterointerfaces Chemistry of Transition Metal-Shielded Zinc Anode for High-Performance Aqueous Zinc Batteries

Abstract

Aqueous zinc metal batteries confront impediments such as severe side reactions and dendrite formation on the zinc metal anode, impeding its commercialization. Although various metals and zinc-metal alloys aim to optimize the zinc anode, the preferential order and reaction mechanisms at the metal/electrolyte interface remain unclear. Here, we utilized magnetron sputtering to create nanolayered metal coatings (Cu, Ti, Ag, Au, Al) on the zinc surface. Notably, the Cu@Zn anode exhibited moderate binding energy with Zn atoms and lower nucleation overpotential than bare Zn, resulting in excellent cycling life (1600 h) and rate performance. Even at a high depth of discharge (80%), the cycling life can still over 200h. In full cells, Cu@Zn//VO2 demonstrated outstanding stability, retaining 95.5% capacity after 600 cycles. Comparison with other metal-coated zinc anodes revealed that Cu@Zn excels due to its moderate binding energy and superior kinetic properties. This study provides valuable insights for optimizing the heterointerface chemistry in zinc anodes, offering general guidelines to regulate various metal anodes suffering the similar challenges.Keywords: Aqueous Zinc ion battery, Metal-nanolayer, Magnetron sputtering, High Zn utilization