Glass‐Ceramics Surface Engineering of Lithium‐Rich Layered Oxide Cathodes Toward High Capacity and High Stability

Abstract Lithium‐rich manganese‐based layered oxides (LMO) cathodes have attracted significant attention due to their outstanding specific capacity, making them promising for high‐energy‐density lithium‐ion batteries in electric vehicles and large‐scale energy storage systems. However, LMO suffers from structural degradation induced by lattice oxygen release and irreversible metal ion migration, ultimately leading to cathode failure. In this work, the glass‐ceramics surface engineering is proposed for the first time to harvest an extraordinary Li‐rich cathode from a dual‐phase protection. The dual‐phase encapsulation contains a unique disordered glassy and crystalline phase of Li ₂ Mn ₂ (SO ₄ ) ₃ (labeled to LMS‐GC), making an ionic conductivity 200 times higher than the crystalline phase. The glass‐ceramics surface with plastic toughness enhances stress transfer efficiency, while this Li‐rich cathode exhibits resistance to particle expansion, cracking, alongside electrolyte erosion during cycling. Ultimately, the optimal surface‐engineered cathode delivers an impressive capacity of 316 mAh g ⁻¹ at 0.1C and maintains 96.3% capacity after 300 cycles at 1C, which is in the forefront LMO list. Glass‐ceramic surface engineering exerts a pronounced mitigating effect on irreversible oxygen release and concomitantly suppresses non‐reversible phase transitions during the cycling of LMO, thereby yielding enhanced capacity retention and cycling stability.