Modulating Lattice Oxygen and Transport Kinetics of Li-Rich Cathodes in All-Solid-State Batteries Through...

Li-rich Mn-based oxide (LRMO) cathodes represent promising candidates for high-energy-density all-solid-state lithium batteries (ASSLBs). Nonetheless, irreversible oxygen release and sluggish transport kinetics result in faded voltage and degraded cycling stability, severely impeding their practical applications in ASSLBs. Herein, a high-quality artificial interface layer was constructed on the LRMO surface via a facile sol-gel method followed by thermal treatment, yielding a Li₃ScF₆ protective layer comprising a Li₃ScF₆ surface coating region and a subsurface Sc doping region. Specifically, Li₃ScF₆ surface coating effectively suppresses continuous interfacial side reactions between the cathode and solid electrolyte, thereby improving interfacial transport kinetics; the strong Sc-O bond stabilizes the lattice oxygen framework and inhibits oxygen release, thereby enhancing the reversibility of the oxygen redox reaction. Consequently, the ASSLBs with the modified LRMO cathode exhibit remarkable fast-charging capability (136.8 mAh g^-1 at 1.0 C) and excellent capacity retention (83.9% after 500 cycles at 0.3 C). In addition, the ASSLBs achieve outstanding long-term cycling stability at a high areal capacity of 4.17 mAh cm^-2, retaining 81.8% of its capacity after 300 cycles at 60 °C. This study offers new insights into the rational design of high-capacity and high-voltage LRMO cathode materials for high-energy-density ASSLBs.