CeO 2 decorated on Co-ZIF-L-derived nickel–cobalt sulfide hollow nanosheet arrays for high-performance supercapacitors

• Published in: Dalton transactions : an international journal of inorganic chemistry 2022-11, Vol.51 (42), p.16093-16101
• Main Authors: Hu, Xuanying, Tao, Kai, Han, Lei
• Format: Article
• Language: English
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/D2DT02300H

Transition metal sulfides have been widely explored as electrode materials for supercapacitors. Unfortunately, the slow redox reaction kinetics and severe volume changes during charge/discharge result in compromised electrochemical performance. In this work, a nickel–cobalt sulfide hollow nanosheet array decorated with cerium oxide nanoparticles (NiCoS/CeO 2 ) has been constructed using a cobalt zeolitic imidazolate framework-L as the template coupled with subsequent solvothermal synthesis. Benefiting from the advantages of the hollow and hierarchical NiCoS nanosheets with a large number of accessible active sites and fast charge transport pathways, as well as CeO 2 layers with rich oxygen vacancies and strong interaction between NiCoS and CeO 2 , NiCoS/CeO 2 exhibits a high specific capacity of 1278.1 C g −1 (1 A g −1 ), which is approximately 1.9 times that of NiCoS. The asymmetric supercapacitor assembled using NiCoS/CeO 2 and activated carbon shows an excellent storage capability (34.9 W h kg −1 at 850.0 W kg −1 ) and an impressive cycle life (91.9% capacitance retention after 10 000 charge and discharge cycles at 10 A g −1 ).