Preparation of complementary electrochromic devices with WO3/PANI and NiO/PB double-hybrid electrodes

Complementary devices with double-hybrid electrodes are prepared, assembled, and studied to improve the performance of complementary devices and take advantage of the excellent performance of composite electrochromic films. WO 3 films are prepared through the seed-assisted hydrothermal method, and polyaniline (PANI) is coated on WO 3 via electrochemical deposition. The electrochemical and electrochromic properties of the WO 3 /PANI composite films are better than those of WO 3 films. The improvement in the electrochromic properties of the WO 3 /PANI composite films is mainly due to PANI’s modification of the surface morphology of the WO 3 films and its excellent conductivity. Then, a complementary device with a double-hybrid electrode is assembled. The WO 3 /PANI and NiO/PB electrode films are used as the cathode and anode of the device, respectively, and KCl solution is employed as the electrolyte. The light modulation range of the complementary device is 55.71%, the coloring time is t c  = 3.2 s, the bleached time is t b  = 8.1 s, and the coloring efficiency is 24.63 cm 2 ·C −1 . All of these values are better than those of the single WO 3 and NiO devices. The electrode reaction process of the complementary device is synchronous and synergetic. Thus, the device exhibits good electrochromic performance.