Manipulating interfacial stability of LiNi0.5Co0.3Mn0.2O2 cathode with sulfide electrolyte by nanosized LLTO coating to achieve high-performance all-solid-state lithium batterie

All-solid-state lithium batteries (ASSLBs) based on sulfide solid-state electrolytes and high voltage layered oxide cathode are regarded as one of the most promising candidates for energy storage systems with high energy density and high safety. However, they usually suffer poor cathode/electrolyte interfacial stability, severely limiting their practical applications. In this work, a core-shell cathode with uniformly nanosized Li0.5La0.5TiO3 (LLTO) electrolyte coating on LiNi0.5Co0.3Mn0.2O2 (NCM532) is designed to improve the cathode/electrolyte interface stability. Nanosized LLTO coating layer not only significantly boosts interfacial migration of lithium ions, but also efficiently alleviates space-charge layer and inhibits the electrochemical decomposition of electrolyte. As a result, the assembled ASSLBs with high mass loading (9 mg cm−2) LLTO coated NCM532 (LLTO@NCM532) cathode exhibit high initial capacity (135 mAh g−1) and excellent cycling performance with high capacity retention (80% after 200 cycles) at 0.1 C and 25 °C. This nanosized LLTO coating layer design provides a facile and effective strategy for constructing high performance ASSLBs with superior interfacial stability.