As positive polarization proceeds, initially dominant I3 -band intensity gives way to the dominance of I5 -band intensity (Fig. , curves from red to blue). Note that the I3 -and I5 -band intensities do not directly correlate with their concentration, since the scattering cross-sections of the polyiodides may vary significantly (resonant vs. non-resonant scattering) . To quantify the Raman band intensity changes, we deconvolute the Raman spectra as shown in Supplementary Fig. 26 . The band intensities as a function of the cell voltage (Fig. )