Optimal Rule-of-Thumb Design of Nickel–Vanadium Oxides as an Electrochromic Electrode with Ultrahigh Capacity and Ultrafast Color Tunability

Abstract

The use of electrodes capable of functioning as both electrochromic windows and energy storage devices has been extended from green building development to various electronics and displays to promote more efficient energy consumption. Herein, we report the electrochromic energy storage of bimetallic NiV oxide (NiVO) thin films fabricated using chemical bath deposition. The best optimized NiVO electrode with a Ni/V ratio of 3 exhibits superior electronic conductivity and a large electrochemical surface area, which are beneficial for enhancing electrochemical performance. The color switches between semitransparent (a discharged state) and dark brown (a charged state) with excellent reproducibility because of the intercalation and deintercalation of OH– ions in an alkaline KOH electrolyte. A specific capacity of 2403 F g–1, a coloration efficiency of 63.18 cm2 C–1, and an outstanding optical modulation of 68% are achieved. The NiVO electrode also demonstrates ultrafast coloration and bleaching behavior (1.52 and 4.79 s, respectively), which are considerably faster than those demonstrated by the NiO electrode (9.03 and 38.87 s). It retains 91.95% capacity after 2000 charge–discharge cycles, much higher than that of the NiO electrode (83.47%), indicating that it has significant potential for use in smart energy storage applications. The superior electrochemical performance of the best NiVO compound electrode with an optimum Ni/V compositional ratio is due to the synergetic effect between the high electrochemically active surface area induced by V-doping-improved redox kinetics (low charge-transfer resistance) and fast ion diffusion, which provides a facile charge transport pathway at the electrolyte/electrode interface.

rGO functionalized (Ni,Fe)-OH for an efficient trifunctional catalyst in low-cost hydrogen generation via urea decomposition as a proxy anodic reaction

“…This can be achieved by developing electrocatalysts derived particularly from the earth-abundant materials that work for both cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER) with high catalytic activity and durability under operational conditions in harsh alkaline (pH ∼ 14) or acidic ( pH ∼ 0) electrolytes. A diverse variety of HER and OER catalysts derived from earth-abundant metalbased materials, such as oxide/hydroxide, [19][20][21][22][23][24] sulfide, [25][26][27][28][29][30] telluride, [31][32][33] selenide, 34,35 phosphide, 36 carbide, 37 nitride, 38 and metal-organic frameworks [39][40][41] have been explored. However, the majority of the works have demonstrated catalysis selectively only for HER or OER, while bifunctional catalytic activity for overall water-splitting is desired.…”

One-step hydrothermal growth of porous nickel manganese layered double hydroxide nanosheet film towards efficient visible-light modulation

“…4f ), which are faster than those of the reported pure NiO film electrode (9.0 s for coloration and 38.9 s for bleaching). 54 The response time is related to many factors, such as the test conditions, the size and thickness of the film, microstructure and intrinsic property of the EC materials. 42 Due to the thinner thickness and lower optical modulation, shorter response times (10.8 s for coloration and 12.6 s for bleaching, respectively) are achieved for the Ni 6 MnO 8 film electrode ( Fig.…”

Research in Electrochromic Supercapacitor – A Focused Review

“…Composites of multiple active materials were also heavily researched to incur synergistic effects between various active materials present for supercapacitor and electrochromic properties. Other conventional transition metal oxides including the ones mentioned above [46][47][48][49][50] were also researched (either for electrochromic, supercapacitor, or both of them), where materials having the characteristics of electrochromic transition and supercapacitor performance have been used widely. Since its initial report on utilizing metal oxide for electrochromic supercapacitor, other kinds of materials have been delved into for an electrochromic supercapacitor.…”