Abstract
Electrochemical processes associated with changes in structure, connectivity or composition typically
proceed via new phase nucleation with subsequent growth of nuclei. Understanding and controlling
reactions requires the elucidation and control of nucleation mechanisms. However, factors controlling
nucleation kinetics, including the interplay between local mechanical conditions, microstructure and local
ionic profile remain inaccessible. Furthermore, the tendency of current probing techniques to interfere with
the original microstructure prevents a systematic evaluation of the correlation between the microstructure
and local electrochemical reactivity. In this work, the spatial variability of irreversible nucleation processes
of Li on a Li-ion conductive glass-ceramics surface is studied with ,30 nm resolution. An increased
nucleation rate at the boundaries between the crystalline AlPO4 phase and amorphous matrix is observed
and attributed to Li segregation. This study opens a pathway for probing mechanisms at the level of single
structural defects and elucidation of electrochemical activities in nanoscale volumes.
