Engineering Ultra-Stable Composite Cathodes via Multifunctional Conductive Additive Architectures to Stabilize Li6PS5Cl-Based All-Solid-State Lithium Batteries

The electrochemical performance of all-solid-state lithium batteries (ASSLBs) can be markedly enhanced by resolving issues arising from cathode conductive additives (CCAs), including excessively high interfacial impedance, inadequate compatibility with solid electrolytes, and insufficient adaptability to the composite cathode. Here, the embedding of ultra-thin and ultra-stable MoS 0.25 Se 1.75 nanosheets onto a vapor-grown carbon fibers (VGCF) substrate are successfully fabricated (MoS 0.25 Se 1.75 @VGCF) as CCAs within a LiCoO 2 -based composite cathode for Li 6 PS 5 Cl (LPSC)-based ASSLBs. This advanced nanostructure design not only effectively suppresses the presence of hydroxyl groups (-OH) on the surface but also induces a synergistic effect that builds up a strong internal electric field and simultaneously lowers the Li + ions migration energy barrier, which can mitigate the occurrence of LPSC degradation at the CCAs|LPSC interface while establishing dual electron/Li + ion transport pathway, thus strengthening the compatibility of composites cathode interfaces for the improvement of electrochemical performance. Consequently, the assembled LCO|MoS 0.25 Se 1.75 @VGCF|LPSC-based ASSLBs exhibit exceptional performance, demonstrating a high discharge capacity of 131.24 mAh·g -1 at 0.1C, a high coulombic efficiency of 92.34%, and an excellent capacity retention of 90.41% after 1000 cycles at 0.5C. This finding introduces a novel synergistic strategy, which offers a fresh approach to mitigate interfacial instability in composite cathodes, thereby further facilitating the commercialization of ASSLBs.