Large-Scale Multifunctional Electrochromic-Energy Storage Device Based on Tungsten Trioxide Monohydrate Nanosheets and Prussian White

Abstract

A high-performance electrochromic-energy storage device (EESD) is developed, which successfully realizes the multifunctional combination of electrochromism and energy storage by constructing tungsten trioxide monohydrate (WO·HO) nanosheets and Prussian white (PW) film as asymmetric electrodes. The EESD presents excellent electrochromic properties of broad optical modulation (61.7%), ultrafast response speed (1.84/1.95 s), and great coloration efficiency (139.4 cm C). In particular, remarkable cyclic stability (sustaining 82.5% of its initial optical modulation after 2500 cycles as an electrochromic device, almost fully maintaining its capacitance after 1000 cycles as an energy storage device) is achieved. The EESD is also able to visually detect the energy storage level via reversible and fast color changes. Moreover, the EESD can be combined with commercial solar cells to constitute an intelligent operating system in the architectures, which would realize the adjustment of indoor sunlight and the improvement of physical comfort totally by the rational utilization of solar energy without additional electricity. Besides, a scaled-up EESD (10 × 11 cm) is further fabricated as a prototype. Such promising EESD shows huge potential in practically serving as electrochromic smart windows and energy storage devices.

A Wearable Second Skin‐Like Multifunctional Supercapacitor with Vertical Gold Nanowires and Electrochromic Polyaniline

“…The recently reported epidermal supercapacitor based on ultrathin CNT film sheds light on the potential. [36,37] PANI (polyaniline) as a popular polymer material has been widely used in supercapacitor area due to its relatively high conductivity, high pseudocapacitance, flexibility, and color-changing characteristics An ideal wearable/implantable bio-diagnostics can be powered by second skin-like energy devices in that they offer advantages such as conformal attachment/integration, lightweightness, and moduli-matching properties. Overall, the development of ultrathin skin-conformable supercapacitors with reasonably high capacitance that can operate under both static and dynamic skin deformations is still on the initial stage, which requires further efforts.…”

“…[31] The application of electrochromic materials offers the superiority of combining energy storage and smart color transitions in one system. [36,37] PANI (polyaniline) as a popular polymer material has been widely used in supercapacitor area due to its relatively high conductivity, high pseudocapacitance, flexibility, and color-changing characteristics An ideal wearable/implantable bio-diagnostics can be powered by second skin-like energy devices in that they offer advantages such as conformal attachment/integration, lightweightness, and moduli-matching properties. [36,37] PANI (polyaniline) as a popular polymer material has been widely used in supercapacitor area due to its relatively high conductivity, high pseudocapacitance, flexibility, and color-changing characteristics An ideal wearable/implantable bio-diagnostics can be powered by second skin-like energy devices in that they offer advantages such as conformal attachment/integration, lightweightness, and moduli-matching properties.…”

A Long‐Life Battery‐Type Electrochromic Window with Remarkable Energy Storage Ability

“…As typical electrochemical devices, EC windows are highly alike to secondary batteries or supercapacitors in both structure and reaction mechanisms, if one regards the EC films and the IS films of EC devices as the batteries’ or supercapacitors’ electrodes . Based on the design concepts of batteries/capacitors, an appealing trend is emerging, to not only simplify EC windows’ structures, but also arm the windows with energy storage ability . The redesigned battery‐/capacitor‐type EC windows are essentially transparent EC batteries/capacitors, which may be able to be integrated into smart grids or can serve as backup power.…”

“…The redesigned battery‐/capacitor‐type EC windows are essentially transparent EC batteries/capacitors, which may be able to be integrated into smart grids or can serve as backup power. In addition, the stored energy in the EC windows can be visually monitored through color changes, making the installed objects much smarter . For instance, Yang and coworkers prepared a thermally evaporated WO 3 /WO 3 symmetrical EC window with remarkable pseudocapacitive energy storage ability.…”

“…This research group also demonstrated a flexible Ag‐nanowire/WO 3 and a hydrothermally deposited NiO electrode with a large capacitance and strong transparence–modulating ability. Bi et al developed a high‐performance EC energy storage device by assembling a WO 3 ·H 2 O and a Prussian white (PW) coating on the transparent conducting glass. During charging, the PW coating was oxidized into Prussian blue (PB), whereas the WO 3 ·H 2 O layer was reduced into Li α WO 3 ·H 2 O, leading to a dramatic color modification from transparent to deep blue.…”