3D reconstruction of SOFC anodes using a focused ion beam lift-out technique

Improvements to electrode performance are essential to accelerate the commercialisation of SOFC technology. A key metric of performance for SOFC electrodes is the length and distribution of three or triple phase boundaries (TPBs) which provide an indication of electrochemical performance. Techniques that can be used to characterise TPB length are highly valuable; with an increasing knowledge of electrode microstructures, electrochemical performance can be optimised. One such technique for electrode characterisation uses focused ion beams (FIB) to sequentially mill and image an electrode surface, obtaining a sequence of 2D images that may be reconstructed in a 3D space. In this paper we present a technique to maximise the quality of the raw data obtained via ex-situ characterisation of electrode micro-sections based on FIB lift-out. With improved raw data, we have been able to conduct semi-automated image analysis to extract key microstructural information, including the length and distribution of TPBs.Reconstructions have been carried out using both single and dual beam instruments; two reconstructions of Ni–YSZ anode structures are presented here.