Plastic deformation associated with phase transformations during lithiation/delithiation of Sn

We report here direct measurements (in situ monitoring) of stress evolution and plastic deformation due solely to first-order phase transformations during lithiation/delithiation of Sn thin films. The ‘stress plateaus’ observed during galvanostatic cycling against Li coincided with the ‘potential (cell voltage) plateaus’ corresponding to two-phase regimes. Preliminary analysis attributes this behaviour to stresses corresponding to eigenstrains associated with the formation of new intermetallic Sn–Li phases with significantly different molar volumes than the parent phases.