Synthesis of Pentiptycene-incorporated Polyanilines for Application as the Electrode Materials of Supercapacitors

Supercapacitors have superior power density and stability as compared with batteries and higher energy density than conventional capacitors, making them attractive for energy storage applications. Polyaniline has been considered as promising supercapacitor electrode materials due to its high environmental stability, controllable electrical conductivity, easy processability and low cost. However, serious mechanical decay during the cycling test occurs for polyaniline devices. We have introduced the rigid and nonplanar pentiptycene scaffold to polyaniline, linear APPANI and star-shaped TAPPANI, to overcome this problem. The results indicate that pentiptycene-containing starting materials act as a reaction template and replace the nucleation step in the chemical polymerization. Both APPANI and TAPPANI display sphere morphology of different size depending on the ratio of pentiptycene anilines versus anilines, which might account for the increased stability on the basis of the electrochemical analysis of cyclic voltammetry. After 1000 cycles, the pristine polyaniline film retains about 63 % of capacity whereas APPANI and TAPPANI retain 87 and 93% , respectively. This work allows one to understand the reaction associated with charging/discharging, and we believe that the stability of polyaniline is intimately related to the morphology. Our results may be helpful for future modification and application of model polyanilines as the electrode materials of supercapacitors.