In the transition from liquid electrolyte to solid-state batteries, the search for solid electrolytes that satisfy all necessary design criteria is ongoing. Argyrodite-type crystals such as Li6PS5Cl have emerged as some of the highest-performing systems and the electrode-electrolyte interphase that forms upon Li cycling is crucial for determining performance. At the atomistic scale, this is a challenging problem with a large phase space where phases can form and decay with various stoichiometries under different conditions.