Fig. 4

Thermodynamic rationale for the strong stress–composition coupling. a The stress distribution within the particle during lithiation according to the relative radial position from the particle center, with the inset showing the lithiated particle geometry. The shell undergoes tensile plastic deformation while imposing compressive hydrostatic stress of 1 GPa on the core. b, c The stress effect on the equilibrium potential of the Li-Sn alloy system (b) and schematic illustrating the spontaneous core dealloying based on the stress-driven potential differences (c). The numbered circles illustrate the discrete timeframes during lithiation. d The experimentally observed stress–composition coupling in Li_xSn. The maximum volume expansion observed before dealloying initiation according to the core-to-particle radii ratio (a/b). The error bars indicate standard deviations in volume from 10 image frames separated by 1 s