Effect of variable temperature loads on characteristics of electrochrome composite Ni (OH)2-PVA films

Abstract

Electrochromic coating is the basis of smart windows with variable optical characteristics. Nevertheless, despite the obvious advantages of using smart windows in construction, their cost is high.We have considered the coatings obtained by the cathodic template method, which are more economical in production. The presented studies are devoted to tests at cyclic temperature loads – repeated cooling and heating. The paper shows the influence of the medium and the method of heat supply (removal) to an electrochromic electrode based on a composite Ni(OH)2-PVA coating as well as the effect of surface preparation before its application.As a medium for cyclic temperature loads, we used air or a working electrolyte – 0.1 M KOH. As a preliminary preparation of the transparent electrically conductive base, we used electrochemical etching of a part of the layer of the electrically conductive transparent coating of tin oxide doped with fluorine in a solution of 1 M HCl.The result of a series of experiments was the discovery of a strong influence of temperature cyclic loads on the final characteristics of electrochromic films. The electrochromic film on the sample, which was subjected to cyclic temperature changes in air and on the substrate without etching, almost completely lost its electrochromic characteristics and adhesion. The sample, which was subjected to thermal stress in an alkali solution, lost its uniformity during coloring.On the other hand, both films, which were deposited on etched substrates, had generally better characteristics than samples deposited without etching and subjected to thermal stress in the air and in alkali. In this case, the sample, which was obtained on the substrate with pretreatment by etching and subjected to temperature cycling in alkali, had even slightly better characteristics than the reference sample