Stabilized Cathode/Sulfide Electrolyte Interface through Conformally Interfacial Nanocoating for All-Solid-State Batteries

All-solid-state lithium batteries (ASSLBs) composed of sulfide-based solid-state electrolyte and LiNixMnyCo1–x–yO2 (NMC) cathode are expected to become the promising next generation of energy storage systems due to their great potential in highly improved safety and energy density. However, the poor interfacial stability between the NMC cathode and sulfide-based electrolyte remains an important challenge for the commercialization of ASSLBs. In this study, a thin layer of fast lithium-ion conductor Li1.3Al0.3Ti1.7(PO4)3 (LATP) with a thickness of 8 nm was coated at the interface between LiNi0.8Co0.1Mn0.1O2 (NCM811) and Li5.5PS4.5Cl1.5 via a facile wet chemical method to improve interfacial stability. It has been found that the nanoscale LATP coating layer can not only accelerate lithium ions across the NCM811/Li5.5PS4.5Cl1.5 interface but also effectively alleviate the interfacial problems. The initial discharge capacity of the as-prepared LATP@NCM811/Li5.5PS4.5Cl1.5/Li batteries at 0.1 C is 151.5 mAh/g, and the capacity retention rate is 81.6% after 100 cycles at room temperature. The results indicate that interfacial modification with the nanosized LATP coating is an effective strategy for providing more possibilities for commercial application of ASSLBs.