Modeling assisted synthesis of Zr-doped Li3-xIn1-xZrxCl6 with ultrahigh ionic conductivity for lithium-ion batteries

Abstract

All-solid-state lithium-ion batteries (ASSLBs) are an important milestone for the future of energy storage because of their capability of impressive energy density and outstanding safety. However, oxide and sulfide solid-state electrolytes (SSEs) suffer from either low ionic conductivity or poor chemical stability. In contrast, halide-based SSEs, are promising as candidate materials owing to high conductivity, good stability, and broad cathode compatibility. Though element doping of the SSEs is an effective and common approach to further improve their electrochemical properties, dopant exploration and optimization through solely experimental trials are both costly and time-consuming. For this aspect, computational simulations for dopant element and concentration screening are adopted in this research and zirconium is selected as a suitable dopant for Li3InCl6. The synthesized Li2.75In0.75Zr0.25Cl6 exhibited Li ionic conductivity of 5.82 × 10−3 S cm−1 at room temperature, which is the highest among reported halide SSEs. The ASSLB formed with Li2CoO2–Li2.75In0.75Zr0.25Cl6–Li/In delivers a high initial capacity of 129.3 mAh·g−1. Conclusively, this work provides an effective approach which combines computational modeling and experimental verification for the development of halide SSEs with improved stability and conductivity. The successful design approach and compelling results provide further possibilities and capabilities in future SSE research.