  A universal challenge facing the development of electrochemical materials is
our lack of understanding of physical and chemical processes at local length
scales in 10-100 nm regime, and acquiring this understanding requires a new
generation of imaging techniques. In this article, we introduce the scanning
thermo-ionic microscopy (STIM) for probing local electrochemistry at the
nanoscale, using for imaging the Vegard strain induced via thermal stress
excitations. Since ionic oscillation is driven by the stress instead of
voltage, the responses are insensitive to the electromechanical, electrostatic,
and capacitive effects, and they are immune to global current perturbation,
making in-operando testing possible.
