Strategies of interfacial chemistry manipulated zinc deposition towards high-energy and long-cycle-life aqueous anode-free zinc metal batteries

The expansion of anode-free configuration in aqueous zinc (Zn) metal batteries (ZMBs) combines intrinsic safety and low cost while satisfying the desire for high energy density. Since all Zn sources in an anode-free ZMB (AFZMB) system come from the Zn-rich cathode and perform plating/stripping onto the anode-side current collector during cycling, excellent Coulombic efficiency (CE) is crucial for its long lifespan. However, the heterogeneous Zn deposition on the substrate and the accompanying water-related parasitic side reactions severely affect the Zn plating/stripping CE, posing a significant challenge to the practical application of AFZMBs. Considering that a stable electrode/electrolyte interface facilitates uniform Zn deposition and delays side reactions, achieving high Zn plating/stripping CE through interfacial chemistry manipulation has attracted extensive attention. In this review, we summarized the research progress of AFZMBs in recent years, emphasizing the importance of stable interfacial chemistry in improving the Zn plating/stripping CE and the electrochemical performance of AFZMBs. We systematically analyzed those strategies to manipulate uniform Zn deposition by constructing stable interfacial chemistry, including the current collector modification and the electrolyte optimization, aiming to attain high-energy and long-lifespan AFZMBs. The purpose of this review is to provide fundamental insights into the design of better AFZMBs by constructing stable interfacial chemistry for efficient Zn plating/stripping.