BI2O3/Bi2S3 rod/sheet nanocomposites as battery-type materials for supercapacitors

Abstract

The fabrication of highly effective negative electrode materials is still a great challenge for achieving high-performance supercapacitors/electrochemical energy storage devices. In this paper, we firstly report a 3D rod-sheet crossed architectures Bi₂O₃/Bi₂S₃ via an in situ converted method. Then we expound the synergistic effect origins between Bi₂O₃ and Bi₂S₃ with two aspects of morphology transformation and density functional theory calculations (DFT), which predict a superb performance. The resultant Bi₂O₃/Bi₂S₃ electrodes display an ultrahigh performance of 3103F g⁻¹ (2792C g⁻¹/775 mAh g⁻¹) at 1 A g⁻¹. An asymmetric device Bi₂O₃/Bi₂S₃//NiS delivers a high energy density of 91.56 Wh kg⁻¹ at a power density of 682.20 W kg⁻¹ and keeps an energy density of 47.30 Wh kg⁻¹ at a higher power density of 7498.00 W kg⁻¹. The theoretical performance limit of the material is discussed. This work will be helpful for pushing forward along the supercapacitor/energy-storage roadmap to achieve the ultra high energy density/power density goal, as well as provides a fabrication strategy of high-performance composites for other research areas.