Electrolyte-Induced Interfacial/Bulk Dual Regulation Enables Negligible Capacity Decay in Li-Rich Cathodes.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41940697.
- Also identified by DOI 10.1002/adma.72969 and PMC identifier 13155261.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
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<sup>3+</sup>-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<sub>2</sub>-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<sup>-1</sup> 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.