Polytriphenylamine derivative with enhanced electrochemical performance as the organic cathode material for rechargeable batteries

Abstract

A novel polytriphenylamine derivative, poly(4-carbamoyl-N,N-diphenylaniline-2,2,5,5-tetramethyl-pyrrolin-1-oxyl) (PTPA-PO) has been synthesized and utilized for the fabrication of the cathode material for organic rechargeable batteries for the first time. The molecular structure, morphology, and electrochemical performance of the obtained polymers were characterized by Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–vis), scanning electron microscopy (SEM), cyclic voltammetry (CV), respectively. Additionally, the charge-discharge performance of the obtained polymers as cathode material were explored by galvanostatic charge-discharge tests. As a result, compared with PTPA, the as-prepared polymer presented an enhanced discharge capacity of 134.5 mAh·g−1 with two well-defined plateaus. Besides, the PTPA-PO, as the cathode material, exhibited an improved rate performance and remained above 90% of the initial capacity over 100 cycles. These outstanding electrochemical performances were attributed to the combination of the conducting polymer PTPA and the radical pendant PO together with the novel linear molecular structure, which not only provided a two-electron redox process, but also enhanced the charge carrier transportation along the polymer chain.