Figure 4: Molecular dynamics (MD) simulations.
From: High damage tolerance of electrochemically lithiated silicon
(a) MD snapshots of brittle fracture in Li-lean Si (a-Li0.5Si) at various stages of applied strain load ɛ, showing the growth of an atomically sharp crack. (b) Zoom-in images near the crack tip in strained a-Li0.5Si, showing the characteristic atomic processes of Si-Si bond breaking (from solid to dashed lines). (c) MD snapshots of ductile response in Li-rich Si (a-Li2.5Si) at various stages of applied strain load ɛ, showing the crack-tip blunting. (d) Zoom-in images near the crack tip in strained a-Li2.5Si, showing the characteristic atomic processes of bond breaking (from solid to dashed lines), formation (from dashed to solid lines) and rotation (angle change between two green lines). Si atoms are coloured by red and Li by blue in a–d. (e) Overall stress-strain responses of a-Li0.5Si (red curve) and a-Li2.5Si (blue curve).
