Facile synthesis of Li2S-P2S5 glass-ceramics electrolyte with micron range particles for all-solid-state batteries via a low-temperature solution technique (LTST)

A lithium ion conductive 75Li2S⋅25P2S5 glass-ceramics electrolyte is, for the first time, successfully synthesized via a new low-temperature solution technique (LTST) and compared to the conventional mechanical-milling technique. Both samples are composed of the highly lithium ion conductive thio-LISICON III analog phase. Due to the uniform dispersion of reactants in an organic liquid, the use of LTST produced significantly smaller and more uniform particle sizes (2.2 ± 1.68 μm) resulting in a 6.5 times higher specific surface area compared to the mechanically-milled sample. A pronounced enhancement of both the rate capability and cyclability is demonstrated for the LTST solid electrolyte sample due to the more intimate contact with the LiCoO2 active material. Furthermore, the LTST sample shows excellent electrochemical stability throughout the potential range of −1 to 5 V. These results suggest that the proposed technique using the optimized LTST process is promising for the preparation of 75Li2S⋅25P2S5 solid electrolytes for use in advanced Li-ion batteries.