Carbon nanotube enables high-performance thiophene-containing organic anodes for lithium ion batteries

Abstract

Poly(thiophene)-based organic compounds with reversible n-type redox behavior can be employed as anode materials for lithium ion batteries (LIBs). However, their inherent problems such as low redox activity, poor rate performance and processing difficultly limit the practical application in LIBs. Herein, a one-dimensional structure-design is reported for a poly(thiophene) derivative (i.e. poly(3-butylthiophene), briefly denoted as P3BT) with a superior lithium storage capability in LIBs. The experimental study and DFT calculation reveal that carbon nanotubes (CNTs) play a critical role in this structure design to promote the electrochemical performances of P3BT. CNTs act as a highly conductive nano-skeleton, which can facilitate the electron transfer, enlarge the electroactive surface area and shorten the ions diffusion path. Besides, the strong π-π interation between P3BT and CNT not only stabilizes the charged and discharged states of P3BT for enhancing the cycling stability, but also compensates the negative effect of introducing of butyl side chains on the energy gap and electron affinity. To the best of our knowledge, the designed one-dimensional P3BT@CNT nanocomposite exhibits a better electrochemical performance compared with the reported thiophene-containing anode materials. This work provides a new insight for the application of thiophene-containing anode materials for LIBs.