Computational Screening of Cathode Coatings for Solid-State Batteries

Solid-state batteries are on the roadmap for commercialization as the next generation of batteries because of their potential for improved safety, power density, and energy density compared with conventional Li-ion batteries. However, the interfacial reactivity and resulting resistance between the cathode and solid-state electrolyte (SSE) lead to deterioration of cell performance. Although reduction of the cathode/SSE interfacial impedance can be achieved using cathode coatings, optimizing their compositions remains a challenge. In this work, we employ a computational framework to evaluate and screen Li-containing materials as cathode coatings, focusing on their phase stability, electrochemical and chemical stability, and ionic conductivity. From this tiered screening, polyanionic oxide coatings were identified as exhibiting optimal properties, with LiH2PO4, LiTi2(PO4)3, and LiPO3 being particularly appealing candidates. Some lithium borates exhibiting excellent (electro)chemical stability at various interfaces are also highlighted. These results highlight the promise of using optimized polyanionic materials as cathode coatings for solid-state batteries.