Deformation Mechanism Maps of Pure Lithium: Their Application in Determining Stack Pressure for All-Solid-State Lithium-Ion Batteries

This study provides a guide for enhancing the stability of the interface between the Li metal anode and solid-state electrolytes (SSEs) in all-solid-state Li-ion batteries by controlling stack pressure. It begins by formulating constitutive equations for various creep deformation mechanisms in pure Li, based on a careful analysis of the experimental data for Li gathered from the literature over the past 60 years. This analysis facilitates the construction of comprehensive deformation mechanism maps (DMMs) for pure Li. Next, it is demonstrated how DMMs can aid in determining the ideal stack pressure to mitigate void/dendrite formation at the interface between the Li metal and SSEs. This optimal stack pressure is found to vary depending on factors such as the Li metal thickness, the aspect ratio of the Li metal, current density, grain size of the Li metal, and temperature. Experimental data are compared with the predictions, and the results are discussed.