DURABLE ELECTROCHROMIC FILMS OF NICKEL-HYDROXIDE VIA CHEMICAL MODIFICATIONS

Nickel hydroxide films prepared by electrodeposition methods exhibit intense electrochromic behavior which deteriorates during repeated coloration/bleaching cycles. The durability of electrochromic nickel hydroxide films has been markedly improved by either the simultaneous incorporation of coprecipitated cobalt and lanthanum ions into the nickel hydroxide lattice or by the introduction of trace quantities of ferricyanide into the alkaline electrolyte. With either of these methods, nickel hydroxide films could be switched for at least several thousand cycles versus less than 500 cycles in systems without these chemical modifications.