Impact of the Solid Electrolyte Particle Size Distribution in Sulfide-Based Solid-State Battery Composites

All solid-state batteries are promising, as they are expected to offer increased energy density over conventional lithium-ion batteries. Here, the microstructure of solid composite electrodes plays a crucial role in determining the characteristics of ionic and electronic pathways. Microstructural aspects that impede charge carrier transport can, for instance, be voids resulting from a general mismatch of particle sizes. Solid electrolyte materials with smaller particle size distribution represent a promising approach to limit the formation of voids and to match the smaller active materials. Therefore, a systematic investigation on the influence of the solid electrolyte particle size on the microstructural properties, charge carrier transport, and rate performance is essential. This study provides an understanding of the influence of the particle sizes of Li6PS5Cl on the charge carrier transport properties and their effect on the performance of solid-state batteries. In conclusion, smaller Li6PS5Cl particles optimize the charge transport properties and offer a higher interface area with the active material, resulting in improved solid-state battery performance. This work highlights the importance of tailoring the microstructure in solid-state batteries. With smaller particle sizes in the solid electrolyte, a more homogeneous ion current distribution can be achieved. The electronic and ionic transport is more balanced and in turn, results overall in better performance of the composite electrode.image