All-solid-state batteries (ASSBs) have emerged as a promising technology to address the current limitations in conventional liquid electrolyte based Li (and potentially Na) ion batteries [1,2]. Significant progress has been made, particularly in developing various solid electrolytes (SEs) [3,4]. However, many challenges remain at the material, electrode, and cell level that need to be tackled [5]. For example, insufficient interface contacts as well as electrochemical instability between the cathode active material (CAM) and the SE in the composite cathode (CC), must be improved, inadequate ionic and electronic charge transport paths must also be overcome [5]. To tackle the abovementioned challenges and also to generate a deeper understanding of performance and processability, it is crucial to investigate the relationship between microstructural and electrochemical properties at the particle, interface, and electrode levels.  

In this talk, I will provide an overview of the state-of-the-art in ASSBs, discussing potential material systems, their advantages and limitations, and recent progress in manufacturing and commercialization. I will then highlight key challenges and optimization strategies, with a particular focus on sulfide-based cathode composites (CCs) and solid electrolytes (SEs) for both lithium and sodium ASSBs [6-9]. Additionally, I will introduce an inert gas characterization workflow that combines high-resolution X-ray microscopy (XRM), correlative femtosecond laser/FIB preparation, and FIB-SEM tomography which enables a detailed understanding of ASSB microstructures across multiple length scales and their correlation with the electrochemical performance of cells and components. 

References
[1] J. Janek J, W.G. Zeier Nature Energy, 2016, 1(9), 1–4.
[2] S. Ohno, W.G. Zeier, Nature Energy, 2022, 7(8), 686-687.
[3] V. Thangadurai, S. Narayanan, D. Pinzaru Chemical Society Reviews, 2014, 43(13), 4714-4727.
[4] M. Tatsumisago, A. Hayashi International Journal of Applied Glass Science, 2014, 5(3), 226-235.
[5] Z. Zhang, Y. Shao, B. Lotsch, Y.-S. Hu, H. Li, J. Janek, L. F. Nazar, C.-W. Nan, J. Maier, M. Arman, L. Chen Energy & Environmental Science, 2018, 11(8), 1945-1976.
[6] P. Minnmann, F. Strauss, A. Bielefeld, R. Ruess, P. Adelhelm, S. Burkhardt, SL. Dreyer, E. Trevisanello, H. Ehrenberg, T. Brezesinski, FH. Richter, J. Janek Advanced Energy Materials, 2022, 12(35), 2201425.
[7] E. Reisacher, P. Kaya, V. Knoblauch, Batteries, 2023, 9(12), 595.
[8] N. Papadopoulos, E. Reisacher, P. Kaya, V. Knoblauch Electrochemical Society Meeting Abstracts, 2023, 244, 357.
[9] R. Ucuncuoglu, L.T. Silvano, T. Schubert, V. Knoblauch, P. Kaya BIO Web of Conferences, 2024, 129, 25057.