Li-rich antiperovskite superionic conductors based on cluster ions

Significance Lithium superionic conductors with Li + conductivity that is comparable with that of the organic liquid electrolytes are critical for the development of practically useful all-solid-state batteries. Here, we show that cluster-based lithium superionic conductors can have very high conductivities of 10 −2 to over 10 −1 S/cm at room temperature, low activation energy under 0.210 eV, a giant band gap of 8.5 eV, and desired mechanical properties that entail great flexibility and can inhibit the dendric growth of Li metal. The high Li + conductivity of the materials results from the thermal excitation of quasirigid unit modes of the cluster ions and the exceptionally large channel size created by mixing large cluster ions together with the elementary ions.