Portraying the ionic transport and stability window of solid electrolytes by incorporating bond valence-Ewald with dynamically determined decomposition methods

Designing inorganic solid electrolytes (ISEs) with both excellent electrochemical stability and high ionic conductivity is an important research direction for all-solid-state batteries. However, due to the electronic conduction of hierarchical decomposition products, there is an imbalance between the ionic transport and electrochemical stability window of the ISEs. Here, we propose a computational approach that incorporates bond valence-Ewald energy analysis and dynamically determined decomposition pathway to portray the competing relationship between ionic transport and stable electrochemical window in solid electrolytes. Following this, we explain the high ionic conductivity and wide electrochemical stability window of Li-Si-B-S solid electrolytes, which features shared corner and edge from tetrahedral SiS4/BS4. Our approach is not only applicable to efficiently characterize the previously reported inorganic solid electrolytes but also expected to accelerate the discovery of more systems. Published under an exclusive license by AIP Publishing.

Automated summary

Designing inorganic solid electrolytes with excellent electrochemical stability and high ionic conductivity is crucial for all-solid-state batteries. However, the electronic conduction of decomposition products causes an imbalance between ionic transport and electrochemical stability window in these electrolytes. In this study, a computational approach that combines energy analysis and dynamically determined decomposition pathway is proposed to depict the competing relationship between ionic transport and stable electrochemical window in solid electrolytes. Furthermore, the high ionic conductivity and wide electrochemical stability window of Li-Si-B-S solid electrolytes are explained using this approach, which features shared corner and edge from tetrahedral SiS4/BS4.