Operando phase-contrast and diffraction tomography of a high-performance lithium alloy anode.

Two-phase lithium alloy anodes are an emerging strategy to achieve industry performance targets in lithium solid-state batteries (SSBs) at minimal energy density penalty. However, the origins of how exactly they achieve this feat remain unclear, preventing their rational-driven development and practical implementation. First investigations, point to the spatial arrangement of the phases within the anode as well as local compositional and microstructural changes during cycling as performance determining. Using a combination of operando full-field X-ray phase-contrast tomography and scanning X-ray diffraction tomography, we will study the first cycle discharge process of two SSBs. One utilizing one of the most promising two-phase lithium alloy anodes, and another with pure lithium. Examination at this level of detail will allow us to identify fundamental relationships between microstructure and performance, accelerating the realization of high-performance room-temperature SSBs.