Ex-situ analysis of electrodes after cycling showed a loss of structural order in both cathodes, but to a significantly greater extent in LC-PB (Figure ). Specifically, Fe K-edge EXAFS showed reductions in 2 nd shell Fe-C/N and Fe-Fe path intensities, indicating a loss of short-range order in both samples, although to a far greater extent for LC-PB. There is a clear correlation from EXAFS between the loss in intensity of 2 nd shell Fe-C/N and the loss of capacity of the PB samples on cycling. No change in phasing was observed in the EXAFS of HC-PB, indicating no bulk formation of a new structure. In contrast, an increased contribution of a Fe-O path, as indicated by a shift in the 1 st feature of the FT towards 1.5 Å, is seen in LC-PB after cycling, attributable to the presence of a new additional oxidic phase. Fe Mössbauer analysis (Figure and Tables &) shows no degradation to HC-PB after cycling, while significant changes were seen for LC-PB. For the spectrum of the LC-PB material, the conventional fitting with 2 Fe (III) doublets was not valid and a further 3rd Fe component with a larger quadrupole splitting was needed to satisfactorily fit the data. The resultant ratio of Area Fe(III) : Area Fe(II) for LC-PB after cycling changed from 1:1 to 3:1, which is far beyond the reasonable limit for PB and implies the presence of an additional Fe phase. A further fit of the LC-PB after cycling spectrum using the original PB components revealed hyperfine parameters of two doublets, which is consistent with the poorly crystalline phase, ferrihydrite (Figure ). The presence of ferrihydrite within the sample is further evidenced when comparing Fe-K edge XANES and EXAFS of the LC-PB used electrode and a ferrihydrite standard (Figures &). There was no change in microstructure, formation of cracks, or exfoliation from the current collector observed in the used samples by SEM (Figure ).