Interface engineering of a hollow core-shell sulfur-doped Co2P@Ni2P heterojunction for efficient charge storage of hybrid supercapacitors

Yue, X., Dong, Y., Gong, J., Gao, Y., Lam, K.-H. , Zheng, Q. and Lin, D. (2023) Interface engineering of a hollow core-shell sulfur-doped Co2P@Ni2P heterojunction for efficient charge storage of hybrid supercapacitors. Journal of Alloys and Compounds, 947, 169591. (doi: 10.1016/j.jallcom.2023.169591)

Abstract

Transition metal phosphides (TMPs) are widely used as supercapacitor energy storage materials due to their abundant valence and high theoretical capacity, but their poor electrical conductivity and low active material utilization lead to low actual capacity and slow kinetics. Herein, we demonstrate the excellent electrochemical properties of sulfur-doped Co2P@Ni2P heterojunction materials prepared using a combination of hydrothermal, ion-exchange and low-temperature annealing approaches. For sulfur-doped Co2P@Ni2P, hollow core-shell microstructures increase the number of electroactive sites and provides a shortcut for electron transport, while sulfur doping promotes the transfer and rearrangement of interfacial charge from Co2P to Ni2P, optimizing the redox ability of the active component. In addition, the S doping and the highly electrochemically active nickel-cobalt phosphide synergistically accelerate the charge transfer, which leads to fast reaction kinetics. Therefore, the obtained S-Co2P@Ni2P exhibits an optimal specific capacity of 1200Cg-1 at 1Ag-1 and excellent rate performance. Furthermore, when combined with activated carbon (AC) for hybrid supercapacitor (HSC), the S-Co2P@Ni2P//AC device shows an excellent energy density of 41.5Whkg-1 and a high-capacity retention of 93% after 15,000 cycles. This work provides a novel approach for the exploration of high-performance and stable phosphorus-based battery-like supercapacitor materials.

• Item Type: Articles
• Additional Information: This work was supported by Natural Science Foundation of Sichuan Province (2022NSFSC0222).
• Keywords: Sulfur-doping, hollow core-shell heterojunction, bimetallic phosphides, hybrid supercapacitors.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Lam, Dr Koko

Creator Roles

Lam, K.-H.: Resources, Writing – review and editing, Supervision

• Authors: Yue, X., Dong, Y., Gong, J., Gao, Y., Lam, K.-H., Zheng, Q., and Lin, D.
• College/School: College of Science and Engineering > School of Engineering > Systems Power and Energy
• Journal Name: Journal of Alloys and Compounds
• Publisher: Elsevier
• ISSN: 0925-8388
• ISSN (Online): 1873-4669
• Published Online: 12 March 2023
• Copyright Holders: Copyright © 2023 Elsevier B.V.
• First Published: First published in Journal of Alloys and Compounds 947: 169591
• Publisher Policy: Reproduced in accordance with the publisher copyright policy