Lithium Oxide Superionic Conductors Inspired by Garnet and NASICON Structures

The key component in lithium solid-state batteries (SSBs) is the solid electrolyte composed of lithium superionic conductors (SICs). Lithium oxide SICs offer improved electrochemical and chemical stability compared with sulfides, and their recent advancements have largely been achieved using materials in the garnet- and NASICON (sodium superionic conductor)- structured families. In this work, using the ion-conduction mechanisms in garnet and NASICON as inspiration, a common pattern of an activated diffusion network and three structural features that are beneficial for superionic conduction: a 3D percolation Li diffusion network, short distances between occupied Li sites, and the homogeneity of the transport path are identified. A high-throughput computational screening is performed to search for new lithium oxide SICs that share these features. From this search, seven candidates are proposed exhibiting high room-temperature ionic conductivity evaluated using ab initio molecular dynamics simulations. Their structural frameworks including spinel, oxy-argyrodite, sodalite, and LiM(SeO3)(2) present new opportunities for enriching the structural families of lithium oxide SICs.

Automated summary

The study explores new lithium oxide SICs for lithium solid-state batteries by drawing inspiration from the ion-conduction mechanisms in garnet and NASICON, resulting in the proposal of seven candidates with high room-temperature ionic conductivity. These new materials, including spinel, oxy-argyrodite, sodalite, and LiM(SeO3)(2), offer new opportunities for enriching the structural families of lithium oxide SICs.