(Invited) Stack Pressure Matters: Understanding and Mitigating Pressure Requirements in Solid-State Batteries

One of the major bottlenecks to commercial adaption of solid-state batteries (SSBs) is the requirement for high stack pressures (>1 MPa). The need for high stack pressures can counteract the energy-density benefits of Li metal anodes at the pack level by requiring bulky and heavy auxiliary fixturing and components [1]. Therefore, there is a need to understand the fundamental bottlenecks to low-pressure operation. From an electrochemical perspective, changes in stack pressure can affect thermodynamic, kinetic, and transport processes throughout the battery [2], requiring detailed analysis to decouple both the beneficial, and detrimental aspects of higher pressures. In this talk, I will describe our efforts to understand and mitigate stack-pressure effects for both Li metal anodes and composite cathodes in solid-state batteries. On the anode side, stack pressure impacts nucleation and growth processes during plating, as well as void formation and contact-loss mechanisms during stripping [3]. In composite cathodes, stack pressure has a direct impact on rate capability, especially for thick electrodes with high active-material content [4]. One of the key findings is that stack pressure should not be thought of as a singular (static) quantity, but rather a property of the system that exhibits unique spatio-temporal dynamics [5]. These dynamic changes will be described using a suite of operando tools to visualize and record the coupled evolution of morphology and pressure. Finally, I will describe strategies and opportunities to mitigate these stack-pressure requirements, pushing SSBs closer towards practical implementation. References [1] M. J. Wang, E. Kazyak, N. P. Dasgupta, J. Sakamoto, Joule 5 , 1371 (2021) [2] E. Kazyak, M. J. Wang, K. Lee, S. Yadavalli, A. J. Sanchez, M. D. Thouless, J. Sakamoto, N. P. Dasgupta, Matter 5 , 3912 (2022) [3] S. E. Sandoval, C. G. Haslam, B. S. Vishnugopi, D. W. Liao, J. S. Yoon, S. H. Park, Y. Wang, D. Mitlin, K. B. Hatzell, D. J. Siegel, P. P. Mukherjee, N. P. Dasgupta, J. Sakamoto, M. T. McDowell, Nature Mater. 24 , 673 (2025) [4] K. G. Naik, M. K. Jangid, B. S. Vishnugopi, N. P. Dasgupta, P. P. Mukherjee, Adv. Energy Mater. 15 , 2403360 (2025) [5] M. A. Thorpe, M. Zhang, D. W. Liao, S. E. Sandoval, Y. Kim, M. T. McDowell, M. D. Thouless, N. P. Dasgupta, Matter 8 , 101955 (2025)