Electrochromic cell

Publication number: 20190346730
Type: Application
Filed: May 14, 2018
Publication Date: Nov 14, 2019
Patent Grant number: 10732476
Inventors: Senad BULJA (Dublin), Rose KOPF (Greenbrook, NJ), Florian PIVIT (Lucan), Wolfgang TEMPL (Sersheim)
Application Number: 15/978,370

In this invention a new structure of EC cell is disclosed. A basic structure of an EC cell is shown in Fig. 1 (a). The ability to tune the high frequency dielectric and optical properties using the standard EC cell was first demonstrated in [1], while in [2] it was shown that the absolute values and the degree of dielectric and optical tunability can be varied in a simple manner – by modifying the heights of substrate layers. The extent of tunability reported was of the order of 20%. The new cell of Fig. 2 features the Ion Storage Film and Electrochromic film moved away from the contact electrodes into the interior of the EC cell. The main reason for this is to avoid shortening the channel height due to the dielectric to metal transition of transition metal oxide layers (Ion Storage and Electrochromic) upon Li ions injection as done with a standard EC cell. The electrolyte layer, on the other hand, was split into two layers and positioned at the point of contact with the bottom and top electrodes. The main reason for this lies with the fact the electrolyte does not exhibit a dielectric to metal transition by losing ions and, therefore, can be positioned in direct contact with top and bottom electrodes. Such an arrangement allows for a greater degree of dielectric tunability and lower dielectric losses, since the channel height is not shortened.  The dielectric tunability achieved with the new structure of the EC cell is no less than 60%, which is over 3 times greater than is the case with the standard EC cell.    

5gFigure 1 Basic structure of standard inorganic EC cell: perspective view (left) and capacitance model (right).

[1] Bulja, S. et al. High Frequency Dielectric Characteristics of Electrochromic, WO3 and NiO Films with LiNbO3 Electrolyte. Sci. Rep. 6, 28839; doi: 10.1038/srep28839 (2016).