Sectioning and Imaging Battery Electrodes Without Mechanical Pre-Preparation
Figure 1:FIB sectioning of Ni-based rechargeable batteries.
FIB sectioning can sometimes be accomplished without the need for mechanical pre-preparation, as is shown here in a FIB secondary electron image taken at the centre of a nickel hydroxide based battery electrode. An overall view of the FIB section is shown in the image inset.
The positive electrodes in Ni-based rechargeable batteries are a complex composite consisting essentially of a mixture of fine powders of Ni and Ni(OH)2 that are pasted into a porous support structure of metallic Ni foam. The performance of these electrodes is strongly dependent on the microstructural characteristics of the constituent materials.
FIB sectioning in this manner minimizes artifacts due to mechanical grinding and polishing and can be invaluable in the analysis of particle delamination, internal cracking or the "pulverization" of the Ni(OH)2 particles, which may result in battery failure after many charge / discharge cycles.