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Figure 8
STXM chemical maps of partially charged LiFePO4–graphene for visualizing the Fe valance distribution: (a) Fe2+ and (b) Fe3+. The grey scale bars show the thickness in the maps. (c) The colour composite map of Fe2+ (blue) and Fe3+ (red). Selected Fe2+ and Fe3+ regions are highlighted by the rectangular and circular boxes, respectively. (d) C K-edge XANES spectra from the selected areas as displayed in (c). It is clear that the fast reaction region (Fe3+) has a much stronger 288 eV peak which could indicate a stronger LiFePO4–graphene interaction (Zhou et al., 2013BB25).

IUCrJ
Volume 1| Part 6| October 2014| Pages 604-613
ISSN: 2052-2525
doi:10.1107/S2052252514021368