Recent progress of artificial interfacial layers in aqueous Zn metal batteries

Aqueous Zn metal batteries (AZBs) are considered as a promising candidate of existing lithium-ion batteries for grid-scale energy storage systems owing to their inherent safety, low cost, and natural abundance. However, the practical application of AZBs is still limited by severe dendrites, corrosion, and hydrogen evolution on zinc (Zn) anode as well as the dissolution of most cathode materials. Although Zn metals are relatively stable in mildly acidic aqueous electrolytes even without solid-electrolyte interphase (SEI), the interfacial structure becomes more significant in resolving the afore-mentioned problems. Herein, we comprehensively review the latest progress on the artificial interfacial layers (AILs) for high performance and safe AZBs. Addressing the fundamentals and challenges of AZBs, the functionality and design of AILs will be introduced discussing the current development of surface modified interphase, electrolyte derived SEI, and cathode/electrolyte interphase. Advanced characterization and simulation methods are also summarized for comprehensive analysis on failure and mechanism of AILs. Finally, our perspectives into future research direction of AILs will be presented.