In Situ Scanning Probe Microscopy of Interfacial Phenomena in Batteries

Scanning probe microscopy (SPM) is a type of microscopy that generates images of surfaces using a probe that scans the specimen. The most important point is to use an SPM unit in an inert atmosphere where water and oxygen are strictly removed, because most of the active materials and their battery reactions are significantly affected. The authors recommend that the SPM unit be placed in an argon glove box with water and oxygen content less than 1 ppm. The cell for in situ SPM measurements is simple, and can be constructed with a commercially available highly purified electrolyte solution and lithium foil as counter and reference electrodes. Metals such as Sn and Si make alloys with lithium metal, and hence are expected as high capacity negative electrodes because their theoretical capacities are much higher than graphite. SPM will be used for the analysis of a variety of battery materials and interfacial reactions by many researchers in the near future.