Stress evolution during cycling of alloy-anode solid-state batteries

Alloy anodes hold promise for enabling high-energy solid-state batteries, but their substantial volume changes during charge/discharge can cause structural and mechanical degradation within the all-solid-state environment. It is therefore critical to understand how material evolution and mechanical stress within alloy-anode-based solid-state batteries are related. Here, we investigate stress (stack pressure) evolution within batteries with composite anodes that contain activematerials such as silicon, tin, and antimony, along with an argyrodite-type electrolyte and LiNi0.33Mn0.33Co0.33O2 cathodes. We measure megapascal-level stress changes that are dependent on the amount of lithium transferred, and we find that stress signatures and hysteresis during charge/discharge are affected by the electrode structure and the active material. We furthermore show that these composite-alloy anodes enable stable long-term cycling with associated cyclic-stress changes. These findings provide new understanding of the relationship between electrochemistry and mechanics within solid-state batteries, which is important because megapascal-level stack pressures are generally necessary for optimal performance.

Automated summary

The study investigates stress evolution within batteries with composite alloy anodes, highlighting the relationship between stress changes and lithium transfer, as well as the impact of electrode structure and active materials. Furthermore, it demonstrates that composite alloy anodes enable stable long-term cycling in solid-state batteries, providing new understanding of the electrochemistry-mechanics relationship.