A unified lattice-surface engineering strategy stabilizing oxygen redox in Li-rich cathodes for all-solid-state batteries.

A coat-sinter-wash strategy for Li-rich Mn-based layered oxides in all-solid-state batteries stabilizes lattice oxygen redox, delivering 80% capacity retention over 500 cycles at 0.5 C and 25°C.

• Why it matters: Irreversible O2 evolution during lattice O2−/O22− redox and high-voltage interfacial degradation limit Li-rich cathodes in ASSBs.
• What they did: Ammonium tungstate is coated on LRMO particles, sintering creates Li vacancies and enables W incorporation as a “chemical rivet,” then washing reconstructs a Li-deficient surface into an in-situ spinel layer.
• The result: The treated cathodes suppress surface oxygen release and structural decomposition, achieving 278.2 mAh g−1 at 0.1 C and 40°C, plus pouch-cell performance of 4.55 mAh cm−2 and 543 Wh kg−1 with a Si anode.