Triple‐Anion Coordination Design for Tuning Li ⁺ Transport Energy Barrier and Promoting the Performance of Li‐Ion Battery

Abstract

Abstract The complex phase transitions of lithiated phosphorus (P) species‐derived interfacial side reactions can be substantially mitigated through a triple‐anion coordination design within the solvation sheath. Our results indicate that the triple‐anion electrolyte exhibits an expanded energy level distribution of solvation sheaths, a low barrier for migrating Li + solvation sheath, a high Li + ‐anion coordination number, a low Li + ‐ether solvent coordination number and an effective NO 3 − ‐FSI − ‐TFSI − adsorption‐decomposition‐sustained release cooperative mechanism that generates a robust rigid‐soft coupled SEI layer during the cycling process. When coupled with a LiFePO 4 cathode, the full cell utilizing the triple‐anion ether electrolyte demonstrates superior stability compared to cells using commercial LiPF 6 ‐EC/DEC electrolytes. More importantly, we establish a universal principle governing P/ether electrolyte compatibility, driven by anion‐rich configurations: a higher Li + ‐FSI − coordination number and a lower Li + ‐solvent coordination number in the triple‐anion electrolyte not only broaden the electrochemical window but also enable a remarkable 94% capacity retention at 50 mA g −1 after 200 cycles for P‐based NCM 523 full cells.