Signal Origin of Electrochemical Strain Microscopy and Link to Local Chemical Distribution in Solid State Electrolytes
Solid State Electrolytes are considered as important components of next-generation batteries, due to their safety related advantages compared to state-of-the-art liquid electrolytes. Based on the rather low ionic conductivites a thorough understanding of local mechansims is of highest importance. In this manuscript we show by electrochemical strain microscopy and energy dispersive X-ray spectroscopy in a correlative approach that it is suitable to probe such materials with high spatial resolution. We observe that the origin of the measured signal rely on electrostatic interactions and thus, is reflecting the local ion concentration. Furthermore, we demonstrate that the signal is reacting sensitively on local variations of the chemical distribution of the sample. Thereby, we contribute an important finding for the understanding of the measurement technique as well as sheding light on the mechanism of ion transport in solid state electrolytes.
Small Methods, 2021, 2001279