Figure 3.

Electrochemical performance of Li‐FeF₂ full cell with various electrolytes and their effect on FeF₂. a) Capacity retention of Li‐FeF₂ full cell tested at 0.1C and 30 °C. Voltage profiles of Li‐FeF₂ full cell with b) G4/TTE, c) EC/EMC. d) Fe 2p XPS data of Li metal after 20 cycles. TEM images of FeF₂ particles after 20 cycles with e) G4/TTE, f) EC/EMC. g) Binding energies of solvent with Fe²⁺ from DFT calculation and corresponding solvation structure (Violet: Fe, Red: O, Gray: C, White: H). XPS data of FeF₂ after 20 cycles h) F 1s, i) N 1s.