Configuring PSx tetrahedral clusters in Li-excess Li7P3S11 solid electrolyte

Abstract

We demonstrate that the Li-ion conductivity can be improved by adding a certain amount of Li (x = 0.25-0.5) as a charge carrier to the composition of glass-ceramic Li7+ xP3S11. Structural analysis clarified that the structural changes caused by the ratio of ortho-thiophosphate tetrahedra PS43- and pyro-thiophosphate ditetrahedra P(2)S(7)4(-) affect the Li-ion conductivity. The ratio of PS43- and P2S74- varies depending on x and the highest Li-ion conductivity (2.5 x 10(-3) S cm(-1)) at x = 0.25. All-solidstate LiNi0.8Co0.15Al0.05O2/Li7.25P3S11/In-metal cell exhibits the discharge capacity of 106.2 mAh g(-1). This ion conduction enhancement from excess Li is expected to contribute to the future design of sulfide-type electrolytes. (C) 2018 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license.