hah: it’s right in the abstract:
We investigate phase stability and ionic transport mechanisms in two recently discovered superionic conductors, Li3OX (X = Cl, Br), from first principles. These compounds, which have an antiperovskite crystal structure, have potential applications as solid electrolytes in Li-ion batteries. We…
To quote myself:
This isn’t to say I don’t believe the experimental result: I just don’t think the mechanism justifies the first law violation motivated above. The sulfur may not be reducing, but something else must be in a stoichiometric balance to the oxidizing lithium to provide the results described in the paper.