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 Li${}_6$PS${}_5$Cl on the charge carrier transport properties and their effect on the performance of solid-state batteries. In conclusion, smaller Li${}_6$PS${}_5$Cl particles optimize the charge transport properties and offer a higher interface area with the active material, resulting in improved solid-state battery performance. (© 2023 The Authors. Advanced Energy Materials published by Wiley‐VCH GmbH)