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Signal Origin of Electrochemical Strain Microscopy and Link to Local Chemical Distribution in Solid State Electrolytes
Author(s) -
Schön Nino,
Schierholz Roland,
Jesse Stephen,
Yu Shicheng,
Eichel RüdigerA.,
Balke Nina,
Hausen Florian
Publication year - 2021
Publication title -
small methods
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.66
H-Index - 46
ISSN - 2366-9608
DOI - 10.1002/smtd.202001279
Subject(s) - materials science , dielectric , electrolyte , fast ion conductor , ion , cantilever , ionic bonding , capacitance , deflection (physics) , electrochemistry , analytical chemistry (journal) , chemical physics , nanotechnology , chemistry , optoelectronics , composite material , electrode , optics , physics , organic chemistry , chromatography
Electrochemical strain microscopy (ESM) is a distinguished method to characterize Li‐ion mobility in energy materials with extremely high spatial resolution. The exact origin of the cantilever deflection when the technique is applied on solid state electrolytes (SSEs) is currently discussed in the literature. Understanding local properties and influences on ion mobility in SSEs is of utmost importance to improve such materials for next generation batteries. Here, the exact signal formation process of ESM when applied on sodium super ionic conductor (NASICON)‐type SSE containing Na‐ and Li‐ions is investigated. Changes in the dielectric properties, which are linked to the local chemical composition, are found to be responsible for the observed contrast in the deflection of the cantilever instead of a physical volume change as a result of Vegard´s Law. The cantilever response is strongly reduced in areas of high sodium content which is attributed to a reduction of the tip‐sample capacitance in comparison to areas with high lithium content. This is the first time a direct link between electrostatic forces in contact mode and local chemical information is demonstrated on SSEs. The results open up new possibilities in information gain since dielectric properties are sensitive to subtle changes in local chemical composition.