Figure 13.

Structural characterization and electrochemical performance analysis of Prussian blue (PB) as a cathode in SIBs. (a,b) SEM images at low and high magnification of the sodium rich PB crystals depicting an uniform cubical morphology. (c) XRD pattern of the synthesized PB sample demonstrating high degree of crystallinity. (d–i) Elemental mapping of the PB sample demonstrating the different constituent elements with uniform distribution. (j) Schematic representation of the PB crystal showing the FCC (face centered cubic) lattice structure, with the Na atoms occupying the interstitial red sports. (k) Galvanostatic charging-discharging curves of the half-cell with PB cathode. (l) CV of the PB cathode system vs. Na/Na⁺ showing the characteristic redox peaks (m) Capacity retention of the PB cathode compared with a control, which is a more defect-filled PB structure. Copyright 2016, American Chemical Society.