In situ atomic-scale imaging of electrochemical lithiation in silicon

Xiao Hua Liu's picture

Link to the article at Nature Nanotechnology:

In-situ TEM movies showing the atomic mechanism of Si lithiation:

In this paper, we show that in situ transmission electron microscopy can be used to study the dynamic lithiation process of single-crystal silicon with atomic resolution. We observe a sharp interface (~1 nm thick) between the crystalline silicon and an amorphous LixSi alloy. The lithiation kinetics are controlled by the migration of the interface, which occurs through a ledge mechanism involving the lateral movement of ledges on the close-packed {111} atomic planes. Such ledge flow processes produce the amorphous LixSi alloy through layer-by-layer peeling of the {111} atomic facets, resulting in the orientation-dependent mobility of the interfaces.