Electrochromism

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

Electrochromic materials and displays

Abstract: Dispersions of electrically conductive particles useful for preparing electrically conductive, essentially ionically isolative composite layers having electrically conductive particles dispersed in a polymer matrix. Composite layers can be used in laminates for electrochromic displays where an ionically conductive layer is in contact with electrochromic material. Such displays comprise means for applying an electrical potential across the interface of the ionically conductive layer and the electrochromic material to generate an electrochromic effect at the interface. Electrochromic materials can be provided in the laminates as layers between the ionically conductive layer and the composite layer of electrically conductive particles dispersed in a polymer matrix. Alternatively, the electrochromic material can be incorporated in the conductive particles in the polymer matrix, e.g. as titanium dioxide coated with antimony tin oxide coated with polyaniline dispersed in an light transmitting polymer matrix. The materials of this invention allow for the high speed fabrication of flexible displays, e.g. by printing methods.

Polyaniline/Vanadium Pentoxide Layer-by-Layer Electrodes for Energy Storage

Abstract: Both polyaniline and vanadium pentoxide (V2O5) are promising electrode materials for electrochemical energy storage, but each has limitations. As a composite, the two components can interact synergistically to form an electrode better than either material alone. Using layer-by-layer (LbL) assembly as a processing technique, we successfully assembled hybrid electrodes containing polyaniline and V2O5. Assembly conditions were chosen to yield films that grew reliably and had a large cycle thickness. Assembly pH and concentration are critical parameters for this particular LbL system. For lower molar mass polyaniline, exponential film growth was observed; for higher molar mass polyaniline, linear growth was obtained. The electrochromic behavior of the film was characterized using UV–vis spectroscopy, and it was found that polyaniline dominated the electrochromic response. However, the electrochemical response possessed contributions from both polyaniline and V2O5. Films made from lower molar mass polyaniline ...

Electrochromic window with high reflectivity modulation

Abstract: A multi-layered, active, thin film, solid-state electrochromic device having a high reflectivity in the near infrared in a colored state, a high reflectivity and transmissivity modulation when switching between colored and bleached states, a low absorptivity in the near infrared, and fast switching times, and methods for its manufacture and switching are provided. In one embodiment, a multi-layered device comprising a first indium tin oxide transparent electronic conductor, a transparent ion blocking layer, a tungsten oxide electrochromic anode, a lithium ion conducting-electrically resistive electrolyte, a complimentary lithium mixed metal oxide electrochromic cathode, a transparent ohmic contact layer, a second indium oxide transparent electronic conductor, and a silicon nitride encapsulant is provided. Through elimination of optional intermediate layers, simplified device designs are provided as alternative embodiments. Typical colored-state reflectivity of the multi-layered device is greater than 50% in the near infrared, bleached-state reflectivity is less than 40% in the visible, bleached-state transmissivity is greater than 60% in the near infrared and greater than 40% in the visible, and spectral absorbance is less than 50% in the range from 0.65-2.5 μm.

Electrochromic Behavior of Nickel Oxide Electrodes I . Identification of the Colored State Using Quartz Crystal Microbalance

Abstract: In the present paper the quartz crystal microbalance is used as a sensitive detector of mass changes taking place during an electrochromic process. Electrochemical and electrochromic characteristics of nickel oxide electrodes strongly depend on the preparation method of the samples. Three different types of materials are studied and their electrogravimetric responses compared: hydroxide film prepared by cathodic deposition from a Ni2+‐containing solution; porous and stoichiometric nickel oxide films formed by anodic oxdation of a nickel electrode in a concentrated solution; and nonstoichiometric films prepared by electron‐beam evaporation. A formula describing the colored film is proposed, taking into account the effect of hydrated alkaline cation (Li+; K+) incorporation.