Traps And Pitfalls In Characterizing All-Solid-State Battery Chemistries

All-solid-state batteries are considered as promising alternative to conventional lithium-ion batteries due to the expected increase in energy density and safety. Both claims, though, still need to be verified at industrial scale and critical voices are becoming louder as commercialization of all-solid-state batteries working at room temperature are delayed further and further.
Even at academic level, fundamental properties of solid electrolytes are still disputed and often a wide variety of different values, often ranging a few orders of magnitude, are reported for specific properties like ionic conductivities or critical current densities [1]. One of the challenges in evaluating solid-state battery chemistries is the lack of common ground for testing materials and cell assemblies. Although methodologies for measuring relevant parameters like the ionic and electronic conductivities of solid electrolytes are well established, the experimental details of the used setups and preparation procedures can differ significantly among different research facilities and are often not sufficiently reported [2, 3]. This renders a direct comparison of data unfeasible, and no common conclusions can be derived.
For promoting more sustainable research and a better use of existing data, the traps and pitfalls of experimental methods used for characterization of these materials need to be identified and properly understood. In this work the experimental challenges and hidden parameters for characterizing solid-state electrolytes and cell assemblies are investigated using sulfide-based electrolytes (Li6PS5Cl) as model compound.
This work was supported by the European Commission through the H2020 program under grant agreement No. 875028 (SUBLIME project) and the Horizon Europe program for research and innovation under grant agreement No. 101069686 (PULSELION project)

References
[1] S.-Y. Ham, H. Yang, O. Nunez-Cuacuas, D. Tan, Y.-T. Chen, G. Deysher, A. Cronk, P. Ridley, J.-M. Doux, E. Wu, J. Jang, Y. Meng, Assessing the critical current density of all-solid-state Li metal symmetric and full cells, Energy Storage Materials, 55 (2023) 455-462.
[2] A. Tron, A. Orue, P. López-Aranguren, A. Beutl, Critical current density measurements of argyrodite Li6PS5Cl solid electrolyte at ambient pressure, J. Electrochem. Soc., 170 (2023) 100525.
[3] A. Beutl, A. Orue, P. López-Aranguren, A.I.P. Martinez, M. Braga, V. Kekkonen, A. Tron, Round-robin test of all-solid-state battery with sulfide electrolyte assembly in coin-type cell configuration, Electrochem. Sci. Adv., (2024) e2400004.