Triple Layer Tungsten Trioxide, Graphene, and Polyaniline Composite Films for Combined Energy Storage and Electrochromic Applications

Abstract

Different polyaniline (PANI)-based hybrid films were successfully prepared by electro-polymerizing aniline monomers onto pre-spin-coated indium tin oxide (ITO) glass slides with WO 3 , graphene, or WO 3 /graphene films. Comparing with pristine PANI, the shifts of the characteristic peaks of PANI-based nanocomposites in UV-visible absorption spectra (UV-vis) and Fourier transform infrared spectroscopy (FT-IR) indicate the chemical interaction between the PANI matrix and the nanofillers, which is also confirmed by the scanning electron microscope (SEM) images. Corresponding coloration efficiencies were obtained for the WO 3 /PANI (40.42 cm 2 C −1 ), graphene/PANI (78.64 cm 2 C −1 ), and WO 3 /graphene/PANI (67.47 cm 2 C −1 ) films, higher than that of the pristine PANI film (29.4 cm 2 C −1 ), suggesting positive effects of the introduced nanofillers on the electrochromic performance. The areal capacitances of the films were observed to increase following the order as bare WO 3 < WO 3 /graphene < pristine PANI < WO 3 /PANI < graphene/PANI < WO 3 /graphene/PANI films from both the cyclic voltammogram (CV) and galvanostatic charge-discharge (GCD) results. The enhanced energy storage and electrochromic performances of the PANI-based nanocomposite films can be attributed to the capacitance contributions of the introduced nanofillers, increased PANI amount, and the rougher morphology due to the embedment of the nanofillers into the PANI matrix. This extraordinary energy storage and electrochromic performances of the WO 3 /graphene/PANI film make it a promising candidate for combined electrochromic and energy storage applications.Polymers 2020, 12, 49 2 of 16 the combination of EDLCs materials with pseudo-capacitive materials is an excellent choice since this approach can take advantage of both the long cycling life of EDLCs and high capacitance merits of metal oxides [7].Meanwhile, electrochromism (EC) has also attracted intense research attention over the last few decades, where the material color changes with electrochemical reactions [8,9]. The persistent but reversible color change of electrochromic materials can be easily controlled by a temporarily employed electrical potential [10], showing wide potential applications such as smart windows, display devices, vehicle sunroofs, and antiglare mirrors for cars [11][12][13]. For example, the light transmittance or reflectance properties of electrochromic windows can be adjusted by voltage through reversible lithium intercalation, allowing the controllable heat transfer and lighting conditions [14]. Various types of materials have been reported to show electrochromic properties, such as transition metal oxides, mixed-valence materials, organic molecules, and conjugated polymers [15][16][17].Among all the materials for supercapacitor and electrochromic applications, conducting polymers belonging to both categories have received a lot of research interests because of their tunable electrical properties, flexibility, and high processability within solution [18]. Among all t...

Carbon Nanomaterials Embedded in Conductive Polymers: A State of the Art

“…Additionally, the color change from various redox reactions makes this CP a promising candidate for electrochromic applications. For instance, Lyu fabricated PANI-based hybrid films by electropolymerizing the monomers onto ITO glass slides with WO 3 , graphene and a heterostructure of both [ 178 ]. Cyclic voltagrams and galvanostatic charge–discharge graphs showed better areal capacitances in the case of WO 3 /G/PANI.…”

Organic Cathode Materials for Lithium‐Ion Batteries: Past, Present, and Future

“…[ 31 ] In 1981, Heeger and coworkers first utilized conductive polymers as the electrode materials for LIBs, which initiated a boom in the research of conductive polymers in the battery field. [ 32 ] The widely researched conductive polymer cathode materials include polyacetylene, [ 33 ] polyaniline, [ 34 ] polypyrrole, [ 35 ] polythiophene, [ 36 ] and polyphenylene, [ 37 ] as shown in Figure 1a.…”

Evaluation of the Covalent Functionalization of Carbon Nano-Onions with Pyrene Moieties for Supercapacitor Applications

“…The use of carbon nanomaterials (CNs) has been quite popular for the construction of supercapacitors (SCs) [1][2][3][4][5], specifically in electrochemical double-layer capacitors (EDCLs) [6,7]. Carbon nanotubes (CNTs) and graphene shells are frequently used for energy storage, commonly as a hybrid metal type material [8][9][10]. The energy storage mechanism is based on the adsorption of electrolyte ions over a large specific surface area of electrically conductive porous electrodes [11,12].…”