Electrolyte‐Induced Interfacial/Bulk Dual Regulation Enables Negligible Capacity Decay in Li‐Rich Cathodes

Abstract

ABSTRACT Lithium‐rich manganese‐based oxides (LRMO) suffer from rapid capacity decay, mainly driven by interfacial instability and bulk structural degradation associated with Jahn‐Teller (J‐T) distortion in Mn 3+ ‐rich regions. Such distortion accelerates surface oxygen activity, triggers nonuniform cathode electrolyte interphase (CEI) formation along with promoted parasitic reactions. Herein, we develop an electrolyte‑induced interfacial/bulk dual regulation strategy that enables negligible capacity decay in Li‑rich cathodes via coordinated interfacial/bulk regulation. In situ characterizations combined with interfacial compositional analyses confirm the dynamic formation of a thin, uniform, and robust LiF/LiBO 2 ‐rich CEI, which stabilizes surface oxygen species and suppresses interfacial side reactions. Meanwhile, local structural analyses combined with theoretical calculations reveal that fluorinated molecules regulate Mn into a low‐spin configuration, thereby alleviating J‐T distortion and preventing bulk structural degradation. Benefiting from this dual induced interfacial‐bulk stabilization effect, LRMO||Li cells deliver an initial capacity of 219.6 mAh g −1 and retain 97.6% of their capacity after 400 cycles. This work provides a new pathway toward electrolyte‐mediated dual stabilization and demonstrates the feasibility of mitigating capacity decay in Li‐rich cathodes via electrolyte‐induced interfacial/bulk regulation.