Design of Lithium Metal Anode and Other High-Capacity Alloy Anodes Solid-State Batteries in Context of Contact Loss between Anode and Solid Electrolyte Separator

Cyclic volume changes and non-uniform electrodeposition/stripping, among other cycling-induced chemo-mechanical degradation of lithium metal and lithium-alloy solid state batteries, lead to contact loss between the anode and the solid electrolyte separator[1, 2]. In-operando experiments have shown ac- celerated short-circuiting behavior due to contact loss in “anode-free” solid-state batteries[2]. Simulations reveal the relationship between active area fraction and the ratio of effective conductivities in made-up active area configurations[3]. Through modeling experiments using imputed active con-tact area of lithium-metal anode batteries, we quantify the effects of this contact loss in terms of accelerated chemo-mechanical degradation and de-creased rate capability. Specifically, we (1) quantify the interfacial resistance due to this contact loss, (2) show non-uniform local current density distribution such that local current densities could exceed lithium filament growth critical current densities, (3) show uniaxial stress inhomogeneity due to non-uniform reaction at the anode/separator interface, and (4) show non-uniform reaction distribution at the positive electrode. Besides allowing for the optimization of designs to minimize contact loss, our work sheds light on tradeoffs in the design of solid electrolyte separators. References [1] John A. Lewis, Francisco Javier Quintero Cortes, Yuhgene Liu, John C. Miers, Ankit Verma, Bairav S. Vishnugopi, Jared Tippens, Dhruv Prakash, Thomas S. Marchese, Sang Yun Han, Chanhee Lee, Pralav P. Shetty, Hyun Wook Lee, Pavel Shevchenko, Francesco De Carlo, Christo-pher Saldana, Partha P. Mukherjee, and Matthew T. McDowell. Linking void and interphase evolution to electrochemistry in solid-state batteries using operando X-ray tomography. Nature Materials, 20(4):503–510, 4 2021. [2] John A. Lewis, Stephanie E. Sandoval, Yuhgene Liu, Douglas Lars Nelson, Sun Geun Yoon, Runzi Wang, Ying Zhao, Mengkun Tian, Pavel Shevchenko, Emilio Martı́nez-Pañeda, and Matthew T. McDowell. Ac-celerated Short Circuiting in Anode-Free Solid-State Batteries Driven by Local Lithium Depletion. Advanced Energy Materials, 2023. [3] Evans Leshinka Molel and Thomas F. Fuller. Application of Open-Source, Python-Based Tools for the Simulation of Electrochemical Systems. Journal of The Electrochemical Society, 170(10):103501, 10 2023.