Electrochromism

About: Electrochromism is a research topic. Over the lifetime, 13097 publications have been published within this topic receiving 294637 citations.

Self-Stacked Reduced Graphene Oxide Nanosheets Coated with Cobalt-Nickel Hydroxide by One-Step Electrochemical Deposition toward Flexible Electrochromic Supercapacitors.

Abstract: The implementation of an optical function into supercapacitors is an innovative approach to make energy storage devices smarter and to meet the requirements of smart electronics. Here, it is reported for the first time that nickel-cobalt hydroxide on reduced graphene oxide can be utilized for flexible electrochromic supercapacitors. A new and straightforward one-step electrochemical deposition process is introduced that is capable of simultaneously reducing GO and depositing amorphous Co(1-x)Ni(x)(OH)2 on the rGO. It is shown that the rGO nanosheets are homogeneously coated with metal hydroxide and are vertically stacked. No high temperature processes are used so that flexible polymer-based substrates can be coated. The synthesized self-stacked rGO-Co(1-x)Ni(x)(OH)2 nanosheet material exhibits pseudocapacitive charge storage behavior with excellent rate capability, high Columbic efficiency, and nondiffusion limited behavior. It is shown that the electrochemical behavior of the Ni(OH)2 can be modulated, by simultaneously depositing nickel and cobalt hydroxide, into broad oxidization and reduction bands. Further, the material exhibits electrochromic property and can switch between a bleached and transparent state. Literature comparison reveals that the performance characteristics of the rGO-Co(1-x)Ni(x)(OH)2 nanosheet material, in terms of gravimetric capacitance, areal capacitance, and long-term cycling stability, are among the highest reported values of supercapacitors with electrochromic property.

Electro-optical device and electro-optical light controlling device

Abstract: An electro-optical device comprising an electrolyte layer held between a pair of electrodes and an electrochromic material placed on at least one of said electrodes, wherein said electrolyte layer comprises an organic material and a chelating agent and an electro-optical light controlling device comprising an electrolyte layer held between a pair of transmissive electrodes and an electrochromic material placed on at least one of said electrodes; wherein said electrolyte layer comprises a non-liquid material of an adhesive or tacky high polymer and a material having coordinating function to a metal.

Characterization and Stability of Electrochromic MoO3 Thin Films Prepared by Electrodeposition

Abstract: Electrochemical, spectroscopic, and structural measurements were used to characterize the electrochromic behavior and stability of electrodeposited MoO 3 thin films. These films are prepared from metal/hydrogen peroxide solution on transparent conductive glass (i.e., ITO). The as-deposited films are partially crystalline and show an improvement in crystallinity after heat-treatment in air at 260°C. These films display reversible electrochromic properties from blue to clear, when cycled in a 1 M solution of lithium perchlorate in propylene carbonate between -0.5 and +2.5 V. The observed effects of heat-treatment on the electrochromic properties are discussed and related to x-ray photoelectron spectroscopy analysis. The elemental depth profiles of colored MoO 3 films were analyzed by secondary ion mass spectrometry.

Reflectance control of an electrochromic element using a variable duty cycle drive

Abstract: An electronic circuit for an electrochromic element. In order to improve the response time of the electrochromic element and reduce the cost and complexity, a modulated signal, such as a pulse width modulated (PWM) signal is coupled to the electrochromic element without signal averaging. In order to compensate for the compressed operating range of the reflectance characteristic under such conditions, the electronic circuit in accordance with the present invention utilizes active loading or alternatively voltage feedback of the electrochromic element to provide a reflectance response characteristic with an uncompressed linear operating range similar to a reflectance characteristic for an electrochromic element with a DC drive circuit.