Operando tomographic characterisation of lithium-alloy anodes for solid-state batteries

Solid-state batteries incorporating inorganic solid electrolytes are a highly attractive option for powering electric vehicles, primarily because of their potential to enable the safe use of lithium metal negative electrodes¹. However, under realistic operating conditions of stack pressure and temperature, pure lithium metal is not a viable electrode for ambient-temperature, low-pressure operation, as it suffers from persistent contact loss with solid electrolytes, even at relatively low current densities². We have recently shown that two-phase alloy microstructures, consisting of a single-phase lithium alloy and a high-diffusivity lithium-containing intermetallic phase, can mitigate this problem³. Operando X-ray computed tomography (XCT) is a powerful technique to observe the evolution of microstructures and interfaces during the cycling of solid-state batteries⁴. In this project, the student will apply operando high resolution XCT to investigate the lithiation mechanism of lithium alloys. The insights gained will inform the design of novel lithium alloy anode microstructures and compositions.

References

1. Burton, M. et al. Techno-economic assessment of thin lithium metal anodes for solid-state batteries. Nat. Energy 10, 135–147 (2024).
2. Aspinall, J. et al. The impact of magnesium content on lithium-magnesium alloy electrode performance with argyrodite solid electrolyte. Nat. Commun. 15, 4511 (2024).
3. Aspinall, J. et al. High diffusivity lithium intermetallic in two-phase alloy negative electrode for solid-state batteries. Research Square (2025) doi:10.21203/rs.3.rs-6759455/v1.
4. Ning, Z., Li, G., Melvin, D.L.R. et al. Dendrite initiation and propagation in lithium metal solid-state batteries. Nature 618, 287–293 (2023). https://doi.org/10.1038/s41586-023-05970-4