Liquid ammoniates: nonaqueous electrolytes for electrochromism

New conductive materials involving Cu+ ions are proposed for electrochromic devices. They are liquid ammoniates which can be used from room temperatur e up to 80 degreesC, and whose conductivity and p(NH3) can be modulated acc ording to requirements. The synthesis does not require strong acids or comp lexing agents such as halide ions. The principle of operation of the electr ochromic material is the reduction of Cu+ to Cu at the transparent cathode while Cut is oxidized to Cu2+ (thus developing a blue color) at the transpa rent anode. The bleaching is realized by the reverse reactions. (C) 2001 El sevier Science Ltd. All rights reserved.