Figure 1: In situ electrochemical and bending test of a Si nanowire.
From: High damage tolerance of electrochemically lithiated silicon
(a) Schematic of the in situ TEM setup for a nano-sized electrochemical cell. (b) Schematic of the buckling and bending test of a partially lithiated Si nanowire subjected to the compressive force F. (c) Sequential TEM images showing the process of axial compression; bucking and bending of the partially lithiated Si nanowire gave rise to a sharply kinked region indicated by the red box (scale bar, 1 μm). (d) Zoom-in TEM image (that is, the red box region in c) showing the brittle fracture of the unlithiated c-Si core, as well as the large tensile deformation (red arrows) and lateral thinning (blue arrows) of the lithiated a-Li3.75Si shell (scale bar, 50 nm). (e) Finite element result showing the simulated elastic-plastic deformation in the nanowire that agrees with the TEM image in d. Colour contour reveals the distribution of axial strain in the lithiated a-Li3.75Si shell, with an extraordinarily large tensile strain of about 47% occurring in the free-standing part of a-Li3.75Si.
