Figure 5. (A) Schematic illustration of solvent separated ion pairs, contact ion pairs, aggregates and localized high concentration electrolyte. (B) Cycle performance of Cu||LFP anode-free cells with HCEs and conventional carbonate electrolytes. Reproduced with permission.[44] Copyright 2019, Wiley-VCH. (C,D) Strategy for formation of robust SEI layer by HCEs with resting protocols and comparison of cycle performance of different SEI formation conditions. . Reproduced with permission.[66]Copyright 2019, American Chemical Society.