Dong, K.; Sun, F.; Hilger, A.; Kamm, P.H.; Osenberg, M.; García-Moreno, F.; Manke, I.: Tracking the phase transformation and microstructural evolution of Sn anode using operando synchrotron X-ray energy-dispersive diffraction and X-ray tomography. Journal of Energy Chemistry 76 (2023), p. 429-437
10.1016/j.jechem.2022.10.014
Open Access Version
Abstract:
The intermediate Li-Sn alloy phases during de/lithiation are identified, and their dynamic phase transformation is unraveled which is further correlated with the volume variation of the Sn at particle- and electrode-level. Moreover, we find that the Sn particle expansion/shrinkage induced particle displacement is anisotropic: the displacement perpendicular to the electrode surface (z-axis) is more pronounced compared to the directions (x- and y-axis) along the electrode surface. This anisotropic particle displacement leads to an anisotropic volume variation at the electrode level and eventually generates a net electrode expansion towards the separator after cycling, which could be one of the root causes of mechanical detachment and delamination of electrodes during long-term operation. The unraveled chemical evolution of Li-Sn and deep insights into the microstructural evolution of Sn anode provided here could guide future design and engineering of Sn and other alloy anodes for high energy density Li- and Na-ion batteries.