Realizing long-cycling all-solid-state Li-In||TiS 2 batteries using Li 6+x M x As 1-x S 5 I (M=Si, Sn) sulfide solid electrolytes

Inorganic sulfide solid-state electrolytes, especially Li 6 PS 5 X (X = Cl, Br, I), are considered viable materials for developing all-solid-state batteries because of their high ionic conductivity and low cost. However, this class of solid-state electrolytes suffers from structural and chemical instability in humid air environments and a lack of compatibility with layered oxide positive electrode active materials. To circumvent these issues, here, we propose Li 6+x M x As 1-x S 5 I (M=Si, Sn) as sulfide solid electrolytes. When the Li 6+x Si x As 1-x S 5 I (x = 0.8) is tested in combination with a Li-In negative electrode and Ti 2 S-based positive electrode at 30 °C and 30 MPa, the Li-ion lab-scale Swagelok cells demonstrate long cycle life of almost 62500 cycles at 2.44 mA cm −2 , decent power performance (up to 24.45 mA cm −2 ) and areal capacity of 9.26 mAh cm −2 at 0.53 mA cm −2 .