High-performance nitrogen and sulfur co-doped nanotube-like carbon anodes for sodium ion hybrid capacitors

Sodium ion hybrid capacitors are of great concern in large-scale and cost-effective electrical energy storage owing to their high energy and power densities, as well as natural abundance and wide distribution of sodium. However, it is difficult to find a well-pleasing anode material that matches the high-performance cathode materials to achieve good energy and power output for sodium ion hybrid capacitors. In this paper, nitrogen and sulfur co-doped nanotube-like carbon prepared by a simple carbonization process of high sulfur-loaded polyaniline nanotubes is introduced as the anode. The assembled sodium ion half cell based on the optimal nanotube-like carbon delivers a high reversible capacity of similar to 304.8 mAh/g at 0.2 A/g and an excellent rate performance of similar to 124.8 mAh/g at 10 A/g in a voltage window of 0.01-2.5 V (versus sodium/sodium ion). For the hybrid capacitors assembled using the optimal nanotube-like carbon as the anode and high-capacity activated carbon as the cathode, high energy densities of similar to 100.2 Wh/kg at 250 W/kg and similar to 50.69 Wh/kg at 12,500 W/kg are achieved. (C) 2019 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.