An electrochemically formed polyazulene(PAz), one of the electroconductive polycyclic hydrocarbons, was studied for its electrochemical properties in order to examine the possibility of utilizing it as a cathode active material of rechargeable lithium battery. The electrode kinetics of PAz film electrode, especially the anion doping-undoping process, were investigated mainly with cyclic voltammetry and FFT impedance method. The cyclic voltammetric results of PAz film showed a highly reversible redox process. Cole-Cole plots for PAz electrode obtained by impedance measurement as a function of doping potential were also found to offer an indication that PAz can be an excellent battery material. The charging-discharging property, and the cyclability of a Li/LiClO4-PC(propylene carbonate)/PAz battery were then studied as a function of the film thickness of PAz cathode. The charging-discharging behavior of Li/LiClO4-PC/PAz was also compared with those of Li/LiClO4-PC/polypyrrole and Li/LiClO4-PC/polyaniline batteries, which had been examined earlier. When compared with Li/LiClO4-PC/polypyrrole or Li/LiClO4-PC/polyaniline batteries, a Li/LiClO4/PAz battery showed fairly high and constant discharge voltage (ca. 3.2V), while keeping 100% of coulombic yield. Inspection by SEM showed that the surface condition of PAz film greatly resembled that of polypyrrole, however, a 10 C cm-2PAz film was prepared with thicker than polypyrrole formed with the same amount of charge of 10 C cm-2.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry