The electrochemical behaviour and the optical properties of commercial indium oxide (ITO) electrodes were investigated in view of their use as counter-electrode in a variable light transmission electrochromic device. The ITO electrodes showed good stability to repeated cyclic voltammetries (CV) in LiClO4—propylenecarbonate (PC) and are colourless in both the reduced and the neutral forms.

The data of a comparative study on electrochromic phenomena of poly-3methylthiophene, poly-2,2′bithiophene and poly-dithieno(3,2-b;2′,3′-d) thiophene in propylene carbonate with 1M LiClO4 are reported. The best results were found with polymethylthiophene. This electrosynthesized conducting polymer is a very promising electrochromic material with high electrochromic efficiency, fast switching response, long life-time and good optical memory.

A study of the electrochromic switching phenomena in polydithienothiophene (pDTT) is presented. This new electrosynthesized conducting polymer shows a very reversible electrochromic behaviour with a high contrast in contast in colour and a swithching time less than one second. The stability to repeated switching and the optical memory are satisfactory up to 11000 tested cycles. Therefore, pDTT appears as a very promising electrochromic material.

Polythienothiophene (pTT) electrode performance is dependent on electrosynthesis conditions of the polymer film. A comparative performance study of pTT, polythiophene (pT) and polydithienothiophene (pDTT) in relation to their use as cathode-active materials in lithium-LiClO 4 -propylene carbonate batteries, showed that pTT polymer electrode was not competitive; as the kinetic of its doping—undoping process was the slowest and the value of its specific charge capacity, was the lowest.

Recently, there has been a growing interest in semiconducting polymers as electrodes in rechargeable lithium batteries. A number of polymers have been

The data from a comparative study of cyclability and stability in LiClO4-propylene carbonate of electrosynthesized polymers: polypyrrole, polythiophene, polydithienothiophene and polythienothiophene are reported and discussed in view of their use as cathode-active materials in lithium-organic electrolytic batteries. Whereas cyclability data suggest that all these polymers, despite performance differences, could be used as cathode-active materials in rechargeable lithium batteries, the stability data seem to indicate, however, that polypyrrole is much more stable than the other polymers in an electrolytic medium of interest in the development of rechargeable lithium batteries.

The characteristics of electrochemically synthesized polypyrrole electrodes have been examined in the lithium perchlorate-propylene carbonate electrolyte, by cyclic voltammetry, charge-discharge cycling, frequency response analysis and by vis-near ir absorbtion spectra. The results show that these polymer electrodes behave satisfactorily in terms of kinetics of the electrochemical doping process, cyclability and charge-discharge efficiency. However, their performance under high rates may be limited by the diffusion of the perchlorate counterion. The preliminary evaluation seems to indicate that polypyrrole may be more stable than other conducting polymers in organic electrolytes of interest for the development of rechargeable lithium batteries.