Patent · US Expired

Electrochromic device with an electrolyte comprising a lithium salt and a sodium salt

US5099356A · kind A · utility

5Cited by
4References
8Claims
0Family size

Assignees

Inventors

Key dates

Filing dateMar 28, 1990
Grant dateMar 24, 1992
Priority date
Expiry dateMar 28, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02F2001/1517
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

The invention relates to an electrochromic (EC) device having oppositely arranged two EC electrode layers. The first EC electrode layer uses Prussian blue, osmium purple or ruthenium purple and accordingly takes on a characteristic color by electrochemical oxidation, and the second EC electrode layer uses a transition metal oxide which takes on a characteristic color by electrochemical reduction, such as WO.sub.3. The space between the two EC electrode layers is filled with an electrolyte solution. When an EC device of this type is left in the bleached state for some period of time and then driven for coloration, the density of coloration is insufficient because of a decrease in the quantity of electricity in the oxidizing and coloring reaction of the first EC electrode layer. The invention solves this problem by using, as the electrolyte solution, a solution of a lithium salt and a sodium salt in an organic solvent prepared such that Na.sup.+ ion amounts to 3-30 mol % of the total of Li.sup.+ ion and Na.sup.+ ion.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.