Sacrificial reduction effects derived inorganic-rich hybrid solid electrolyte interfaces for long-term and high reversibility aqueous zinc-ion batteries

Constructing a stable solid electrolyte interphase (SEI) on zinc anodes is a key strategy to stabilize the zinc electrode/electrolyte interface. However, conventional SEIs formed through zinc salt decomposition typically exhibit poor corrosion resistance and low conductivity, hindering Zn²⁺ diffusion and causing uneven deposition and dendrite growth. Here, we introduce 1,2-Dimethoxyethane (DME) co-solvent and lithium bis(fluorosulfonyl)imide (LiFSI) additive into the aqueous electrolyte. The sacrificial reduction of LiFSI enabled the formation of a hybrid inorganic-rich SEI on the Zn anode. This unique SEI effectively expels corrosive H₂O molecules from the surfaces of Zn anodes. In addition, this LiF- and Li₃N-rich SEI can provide fast ion transport pathways, thereby achieving uniform Zn deposition. As a result, the SEI facilitates reversible zinc stripping and plating on Cu foils for over 2000 cycles (4000 h) with an average Coulombic efficiency (CE) of 99.64 %. In Zn || Zn symmetric cells, it achieves high reversibility over 3000 h of plating/stripping cycles, with a cumulative capacity of up to 6000 mAh cm⁻². The SEI also ensures stable performance across a broad temperature range (−30 to 30 °C). This work provides a promising strategy for enabling long-term, highly reversible zinc-ion batteries (ZIBs) and other metal batteries.