Atomic-Scale Observation of Lithiation Reaction Front in Nanoscale SnO 2

In the present work, taking advantage of aberration-corrected scanning transmission electron microscopy, we show that the dynamic lithiation processofanodematerialscanberevealedinanunprecedentedresolution.Atomically resolved imaging of the lithiation process in SnO2 nanowires illustrated that the movement, reaction, and generation of b =( 111) mixed dislocations leading the lithiatedstripeseffectivelyfacilitatedlithium-ioninsertionintothecrystallineinterior. The geometric phase analysis and density functional theory simulations indicated that lithium ions initial preference to diffuse along the (001) direction in the {200} planes of SnO2 nanowires introduced the lattice expansion and such dislocation behaviors. At the later stages of lithiation, the Li-induced amorphization of rutile SnO2 and the formation of crystalline Sn and LixSn particles in the Li2O matrix were observed.