First, the positive (V2O5 NWs) and negative electrodes (VN NWs) were synthesized for building the high–energy density FASC device because of their high theoretical capacities and broad operating potential windows (14). To uncover the microstructure and morphology of the samples, we used field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Figure S1A [scanning…