Polyaniline/reduced graphene oxide nanosheets on TiO2 nanotube arrays as a high-performance supercapacitor electrode: Understanding the origin of high rate capability

• Published in: Electrochimica acta 2021-02, Vol.368, p.137615, Article 137615
• Main Authors: Ding, Yangbin, Sheng, Haonan, Gong, Baozhi, Tang, Peisong, Pan, Guoxiang, Zeng, Yunxiong, Yang, Liming, Tang, Yanhong, Liu, Chengbin
• Format: Article
• Language: English
• Subjects: Arrays; Charge materials; Electrochemical energy storage; Electron transfer; Energy storage; Foils; Graphene; Nanosheets; Nanotubes; Polyaniline; Polyanilines; Rate capability; TiO2 nanotube arrays; Titanium dioxide
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2020.137615

As charge storage occurs both on the surface and in the bulk of material, the dynamics of charge storage is a key issue in the practice of energy storage. Although the energy storage can be increased in the bulk of the material, it often suffers from a quite slow kinetics, which seriously hinders the rate capability. Keeping high surface-induced capacitive contribution is proposed to address this issue. Herein, a porous scaffold, TiO2 nanotube arrays grown in a Ti foil (TiO2 NTs/Ti) is selected as the current collector for electrodeposition of porous polyaniline/reduced graphene oxide (PANI/rGO) hybrid film. The capacitive contribution of PANI/rGO@TiO2/Ti is quantitatively evaluated, showing a high surface-induced capacitive contribution up to 58% at high rates (>25 mV s−1) and large electron transfer coefficient of 2. As a result, the electrode not only shows an ultrahigh specific capacity of 908 C g−1 at 1 mV s−1, but also delivers an outstanding rate capacity of 310 C g−1 at 500 mV s−1. PANI/rGO@TiO2/Ti also shows excellent cycling stability with 80% capacity retention after 10,000 cycles at a high current density of 25 A g−1.