Pyridine Complexes as Tailored Precursors for Rapid Synthesis of Thiophosphate Superionic Conductors

Abstract

Room temperature solution synthesis of electrolytes for all-solid-state batteries has garnered much interest in the past years as a more scalable and efficient alternative to traditional solid-state syntheses. Li3PS4, a model solid electrolyte often studied, is typically produced from Li2S and P4S10; the latter exists as a molecular solid in an adamantane-like cage structure, and it has been posited that from its robustness arises a rate-limiting reaction step. In this work, we have applied chemistry inspired from the organic thionation literature to easily transform the cage-like P4S10 into more reactive stabilized linear P2S5 molecules. This new reagent was used to drastically reduce the synthesis time of Li3PS4 in acetonitrile from days to hours. Because the long reaction time of many solvent routes to produce solid electrolytes is considered a bottleneck for commercialization, this work shows great promise for looking toward more fundamental chemistry in order to optimize solution syntheses.