Several PS materials have demonstrated high technological value and/or unique properties not found in other groups of materials. For example, Li 10 GeP 2 S 12 demonstrated record ionic conductivity in 2011 and Li-based thiophosphates are among the most promising solid electrolytes for solid-state batteries; in 2020, CuInP 2 S 6 was found to be a ferroelectric material with exotic features; and in 2020, unique excitonic effects were found in atomically-thin, antiferromagnetic NiPS 3 . In general, thiophosphates with 3D structural dimensionality have predominantly been investigated as solid electrolytes for Li and Na batteries and as non-linear optical materials. Thiophosphates with 2D structural dimensionality (often referred to as "van der Waals" materials) have mainly been studied in the fields of Li and Na battery electrodes , ferroelectrics , magnetic materials , and catalysts for the oxidation of S 2- , the reduction of CO 2 , the HER and the OER .