Showing papers by "Kuo-Chuan Ho published in 1990"

Electrochemical Impregnation of Nickel Hydroxide Flow‐Through vs. Stagnant Electrodes

Abstract: The electrochemical impregnation of nickel hydroxide in porous electrodes has been investigated both experimentally and theoretically. The loading level and plaque expansion were the most important parameters to be considered. The effects of flow, counterelectrode placement, and pH have been identified. A novel flow‐through electrochemical impregnation is proposed in which the electrolyte is forced through the porous nickel plaque. The thickening of the plaque can be reduced while maintaining high loading capacity. A mathematical model for flow‐through electrochemical impregnation is presented which describes the transport of the nitrate, nickel, and hydroxyl ions and the consecutive heterogeneous electrochemical reduction of nitrate and the homogeneous precipitation reaction of nickel hydroxide. The distributions of rate of precipitation and active material within the porous electrodes are obtained. Deviation of loading curve from Faraday's law, in the case of stagnant electrodes, is believed to be the dissolution of surface‐deposited ; while the main loss in loading, in the case of flow‐through electrodes, is attributed to the hydrodynamic washout.

The Influence of Terminal Effect on the Performance of Electrochromic Windows

Abstract: A simple theory of potential and current distributions developed elsewhere, based on the parallel-plate electrochemical cell under linear kinetics, is applied to electrochromic windows. In our case, only the working electrode has appreciable resistance. The model permits a predictive analysis of the effects of operating current density, cell length, cell length, and sheet resistance of this transparent electrode on the device's performance in the darkening process

Electrochromic window with polymer layer

Abstract: An electrochromic window (10) includes a first transparent substrate (14), an electroconductive film electrode (16), a transparent electrochromic film (18) in contact with said electroconductive film (16), an ion-conductive layer (26) in contact with said electrochromic film (18), a counter electrode (22) in contact with said ion-conductive layer (26), and a second transparent substrate (24) overlaying the counter electrode (22). A preferred copolymer electrolyte is a reaction product of a sulfonic acid monomer such as acrylamidomethylpropane sulfonic acid or ethylene sulfonic acid, and a hydrophilic acrylate comonomer such that the copolymer is curable with ultraviolet radiation. The optimum moisture content of the ion-conducting polymer sheet (26) is maintained by means of a moisture vapor barrier (38) surrounding the perimeter of the cell. A plurality of bus bars (34) extend across the electroconductive film electrode (16) to distribute electrical current throughout the film electrode and provide a more uniform current density between the film electrode (16) and the counter electrode (22).