Method for producing electrochromic material and electro-optical device using same
AssigneeEIC Laboratories, Inc.
InventorsStuart F. Cogan, R. David Rauh
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Abstract
A method for preparing an oxidatively coloring electrochromic layer of composition M.sub.y CrO.sub.2+x (0.33.ltoreq.y.ltoreq.2.0 and x.ltoreq.2) where M=Li, Na or K and an electrochromic devise employing this layer with improved transmittance modulation, improved thermal and environmental stability, and improved resistance to degradation in organic liquid and polymeric electrolytes. The M.sub.y CrO.sub.2+x provides complementary optical modulation to cathodically coloring materials in thin-film electrochromic glazings and electrochromic devices employing polymeric Li.sup.+ ion conductors.
Claims14
The method of forming an oxidatively coloring electrochromic film comprising the steps of:
- depositing CrO.sub.3-k, where k<1.5;
- depositing an alkali metal M onto said CrO.sub.3-k ;
- heating to a temperature of 196 C. or higher said CrO.sub.3-k and said alkali metal M to form (zM)M.sub.y CrO.sub.2+x (0.33<y<2.0, x<2) by reaction with M;
- whereby said metal M reacts to form a compound or compound mixture comprising separate phases of stoichiometric M--Cr--O compounds, in which M cannot be extracted electrochemically, and
- whereby the excess zM is able to be extracted and re-inserted into M.sub.y CrO.sub.2+x electrochemically.
Dependencies are inferred from the claim text.