Green fabrication of a complementary electrochromic device using water-based ink containing nanoparticles of WO₃ and Prussian blue

Abstract

We fabricated a complementary electrochromic device (ECD) by using water-dispersible nanoparticles (NP) of Prussian blue (PB) and WO3 by using a wet process, which involved just coating.

Flexible electrochromic devices based on tungsten oxide and Prussian blue nanoparticles for automobile applications

“…Water-dispersed PB and WO 3 NP inks were prepared by following methods reported in our previous papers. [14][15][16]32 O, and the suspension was stirred at room temperature for 1 week. Polyvinyl alcohol (PVA; 10 wt%) was added for increased viscosity and adhesion of the ink to ensure that a uniform PB lm was formed.…”

“…The ECDs were evaluated in accordance with protocols used in our previous studies. 14,32 The chromaticity was measured using a UV-visible (UV-vis) spectrophotometer (SD 3000, Nippon Denshoku Industries Co. Ltd), while the haze was determined using a haze meter (NDH 7000, Nippon Denshoku Industries Co. Ltd). The chromaticity coordinates (a* and b*) and luminance (L*) data were calculated from the transmittance spectra of PET-based and glass-based ECDs in their coloured and bleached states.…”

“…We have previously developed a complementary coated ECD using WO 3 and PB nanoparticles (NPs). 14,32 The WO 3 and PB thin lms were coated with an ink containing each of these NPs dispersed in water, thus ensuring processing safety. Slit coating was also evaluated for the fabrication of large-area thin lms on a G2 (370 mm  470 mm)-sized indium tin oxide (ITO)-coated glass substrate.…”

Lithium-Ion-Assisted Ultrafast Charging Double-Electrode Smart Windows with Energy Storage and Display Applications

“…At present, batteries containing both an anode and cathode with electrochromic materials are rather rare. And the processes of charging and discharging an electrochromic battery usually depends on the external power source, which causes a waste of energy and increases the complexity of the system to some extent. − As we know, electron transfer could spontaneously occur between electrodes with materials possessing a potential difference when they are connected. This is a thermodynamically spontaneous process (Δ G < 0).…”

Electrochromic properties of WO₃ thin films fabricated by magnetron sputtering, ion plating, and spin coating: A comparative investigation

“…12) 17) In our previous work, we investigated the combined use of WO 3 and Prussian blue (PB; Fe 4 [Fe(CN) 6 ] 3 ) as materials for EC devices in an effort to improve their properties, such as the contrast between the blue and transparent states. 18) The open-framework structures of PB analogues are well known with respect to EC materials. The EC behavior of PB involves three redox states, namely blue (Fe III , Fe II ), transparent/colorless (Fe II , Fe II ), and green (Fe III , Fe III ).…”