Solvent‐Anchored Electrolyte Enables Stable Operation of 600 Wh Kg ⁻¹ Lithium Metal Pouch Cells Under High‐Voltage

Abstract

ABSTRACT Lithium metal batteries (LMBs) are regarded as promising candidates for next‐generation high‐energy‐density storage systems. However, their practical application is severely hindered by rapid performance degradation under high‐voltage and lean‐electrolyte conditions. Constructing an anion‐enriched solvation structure to generate an inorganic‐rich solid electrolyte interphase (SEI) is critical for ensuring the stable operation of lithium metal batteries. Herein, a novel anion‐enrichment strategy is proposed by introducing a rigid cationic species (F‐TEDA + ) as a molecular anchoring additive to design a solvent‐anchored electrolyte (SAE). F‐TEDA + anchors solvent molecules via strong ion–dipole interactions, enabling the formation of an anion‐enriched solvation structure comparable to that of high‐concentration electrolytes, even at an ultralow additive dosage and conventional salt concentration. Notably, the rigid molecular framework of F‐TEDA + endows it with excellent electrochemical stability, allowing persistent regulation of the solvation structure during long‐term cycling. As a result, a 14.2 Ah Li‖Ni95 pouch cell reaches 615.3 Wh kg −1 and retains 91.4% capacity after 70 cycles at 4.5 V. This work proposes a nonconsumable solvation regulation strategy, providing a new avenue for the development of high‐voltage, high‐energy‐density lithium metal batteries.