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

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 NO₃ ^--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 LiFePO₄ cathode, the full cell utilizing the triple-anion ether electrolyte demonstrates superior stability compared to cells using commercial LiPF₆-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 NCM₅₂₃ full cells.