Fig. 8. (a) STEM image of platelet after 10 CV cycles, showing the area of interest for EELS mapping analysis (red) and integrated-area spectral analysis (white sites labelled ‘1’ and ‘2’). (b) EELS signal map for the area of interest. (c) Fe and (d) Ni maps. (e) Comparison of the integrated spectra acquired from sites near platelet edge versus near the centre, acquired using a common pre-Fe background, with an increase in the Ni : Fe peak intensity ratio from site 1 to 2.