781236.fig.004
Figure 4: Insertion and extraction of Li+ ions into/out of the WO2/TiO2/FTO electrode. The inserted charge (a bottom half cycle) of the saturated coloration state and the completely bleaching state (a top half cycle), respectively, are 𝑄 i n = 21 mC × cm−2 and 𝑄 e x = 19 mC × cm−2.