Organic polytriphenylamine derivative-based cathode with tailored potential and its electrochemical performances

In this work, the triphenylamine derivatives with the different electron donating/with-drawing groups, such as 4-(diphenylamino)benzonitrile (TPA-CN), 4-methyltriphenylamine (TPA-CH3) and 4-methoxytriphenylamine (TPA-OCH3) were successfully synthesized, and the corresponding polymers were then prepared by chemical oxidative polymerization. The chemical structure, morphology and charge-discharge performance of the prepared polymers as the cathodes were characterized by fourier transform infrared spectroscopy (FTIR), ultraviolet visible spectroscopy (UV-vis), scanning electron microscopy (SEM), cycling voltammograms (CV) and galvanostatic charge-diacharge testing, respectively. The results showed that the different electronic effect groups affected obviously the redox potential of polytriphenylamine, in which the electron with-drawing group improved the potential plateaus of the polytriphenylamine, while the electron donating groups generally led to the opposite results. And specially, the introduction of CN group as the electron with-drawing group into polytriphenyamine obviously improved the potential plateaus of the lithium ion battery from 3.6 V of PTPAn to 3.8 V of PTPA-CN. The explored work would provide a valuable reference for preparing the organic cathode materials with the high redox potential by the molecular design method.