Interplay of Ionic and Electronic Properties of LPSCl with Its Micro- and Macrostructural Dynamics

A systematic study is performed to correlate the electronic and ionic properties of Li6PS5Cl (LPSCl) with its mechanical properties and structural dynamics as a function of pressure and temperature. The crucial role of mechanical and structural dynamics, from the atomic to the macroscale, is investigated to optimize electrolyte properties and assembly. Ionic conduction dynamics are described via particle rearrangement, plastic deformation, contact formation, and activation volume with respect to structural dynamics during compression and decompression. The results demonstrate the potential for optimizing electrolyte performance through the interplay of opportune pelletizing and stacking pressures. High pelletizing pressures enhance ionic conductivity and electrical contact uniformity, whereas pressures below 80 MPa introduce interface contact instabilities. Additionally, it is shown that applying high pressure (above 10 GPa) results in irreversible structural modifications. At pelletizing pressures, ionic conductivity is dominated by grain boundaries; at stacking pressures, however, they contribute equally to the grain bulk. As a result of positive activation volume, ionic conductivity peaks at a stack pressure of 80 MPa, after pelletizing at a higher pressure. Defects can introduce donor levels into the energy gap of LPSCl, which can be adjusted to improve battery performance.