Regensburg 2016 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 26: Poster session II
MM 26.23: Poster
Dienstag, 8. März 2016, 18:30–20:30, Poster B3
Towards Conductivity Measurements in Battery Materials Using Scanning Electron Microscopy — •Sebastian Sturn, Ute Golla-Schindler, Jörg Bernhard, and Ute Kaiser — Electron Microscopy Group, Ulm University, Albert-Einstein-Allee 11, 89069 Ulm
There are several ways of determining the conductivity of bulk materials, especially known in the field of solid state physics. However, the experiments will usually yield only the mean conductivity. We try to spatially resolute the electrical conductivity of state-of-the-art secondary battery electrodes by means of injecting electrons using an SEM.
In a first step, it is necessary to determine the amount of incident electrons absorbed in the bulk material. It is therefore crucial to quantitatively characterize any electron current exiting the specimen, namely the secondary electron and backscattered electron current, since the absorbed current is given by Iabs = Iincident − ISE − IBSE.
The approach is to directly measure ISE and IBSE for every spot of the scan pattern. By using Focused Ion Beam (FIB), we are able to get rid of the specimen’s topography and prepare polished surfaces. As the secondary electron yield is mainly dependent on the topography, we are able to, at least as a first approximation, assume that the secondary electron current is constant.
The use of a Gas Injection System (GIS) allows for sputtering platinum contacts on top of the specimens. We use these platinum pads as contact areas for micromanipulators to read out absorbed currents.