Huiying Qu

Versatile displays based on a 3-dimensionally ordered macroporous vanadium oxide film for advanced electrochromic devices

Three-dimensionally ordered macroporous (3DOM) vanadium oxide film was fabricated by anodic deposition of vanadium oxide into colloidal crystal template. The as-prepared films were investigated by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). The electrochemical and electrochromic behaviors of the films were studied in 1.0 M LiClO4–propylene carbonate solution. Because of the larger surface area and shorter diffusion distance, the 3DOM film exhibited better electrochromic performance than the dense film prepared without the template. The 3DOM film exhibited multicolor changes (yellow, green and black) in the voltage window from +1 to −1 V with a high transmittance modulation of ca. 34% at 460 nm and high switching speed (1.5 s for coloration and 2.1 s for bleaching). Cyclic voltammetry (CV) and chronoamperometry measurements showed that the 3DOM structure is beneficial for Li+ diffusion in vanadium oxide films. An ITO/vanadia/gel/PEDOT:PSS/ITO electrochromic device was assembled, and the device showed multicolor changes with fast switching speed (3.5 s for anodic coloration and 3.4 s for cathodic coloration) and good cycling stability.

Recent advances in multifunctional electrochromic energy storage devices and photoelectrochromic devices

Multifunctional devices integrated with electrochromism and energy storage or energy production functions are attractive because these devices can be used as an effective approach to address the energy crisis and environmental pollution in society today. In this review, we explain the operation principles of electrochromic energy storage devices including electrochromic supercapacitors, electrochromic batteries, and the photoelectrochromic devices. Furthermore, the material candidates and structure types of these multifunctional devices are discussed in detail. The major challenges of these devices along with a further outlook are highlighted at the end.

A rapid-response electrochromic device with significantly enhanced electrochromic performance

A novel electrochromic device (ECD) was constructed with two same-material electrochromic layers deposited on indium-tin oxide (ITO)-coated glass substrates, a double-sided ITO-coated glass substrate, and a gel electrolyte. The device exhibited fast coloration/bleaching response and significantly enhanced optical modulation and coloration efficiency compared to traditional ECDs.

Improved Electrochromic Performance of Poly(3,4-ethylenedioxythiophene) by Incorporating a Three-Dimensionally Ordered Macroporous Structure

In this paper, three-dimensionally ordered macroporous (3DOM) poly(3,4-ethylenedioxythiophene) (PEDOT) films were electropolymerized from an ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF6 ). The electrochromic performances of the 3DOM PEDOT films were studied. The 3DOM films exhibited high transmittance modulation (41.2 % at λ=580 nm), high ionic fast switching speeds (0.7 and 0.7 s for coloration and bleaching, respectively), and enhanced cycling stability relative to that exhibited by the dense PEDOT film. The relationship between the declining behavior of the transmittance modulation and the nanostructure of the film was investigated. A three-period decay process was proposed to understand the declining behavior. The 3D interconnected macroporous nanostructure is beneficial for fast ion and electron transportation, high ion accessibility, and maintenance of structure integrity, which result in enhanced cycling stability and fast switching speeds.

Improved Electrochemical Cycling Durability in a Nickel Oxide double layer film

For the first time, a crystalline-amorphous double-layered NiOx film has been prepared by reactive radio frequency magnetron sputtering. This film has exhibited improved electrochemical cycling durability, whereas other electrochromic parameters have been maintained at the required level, namely, a short coloration/bleaching time (0.8 s/1.1 s) and an enhanced transmittance modulation range (62.2 %) at λ=550 nm. Additionally, the double-layered film has shown better reversibility than that of amorphous and crystalline single-layered films.

Review: recent progress in ordered macroporous electrochromic materials

Electrochromic (EC) materials have the ability to change their optical properties when exposed to a low electrical voltage. They have found a wide range of applications in smart windows, low-power displays, and spacecraft thermal control. To improve the practical applicability of EC materials, rational design and exploration of their architectures play a crucial role. Among various architectures, forms of inverse opal structure including two dimensionally and three dimensionally ordered macroporous structure (2DOM and 3DOM) exhibit outstanding and specific performance. In this review, several examples of 2DOM and 3DOM EC materials with detailed preparation methods are presented, followed by a detailed discussion of various aspects in ordered macroporous structural EC films, including common features, structure transition and photonic band gap tuning. In addition, the typical five layered design for the EC material-based device is given, as the device is of the most importance in researches as well as applications. Finally, conclusions and outlook are provided at the end of this review.