Multifunctional sulfur doping in cobalt-based materials for high-energy density supercapacitors

• Published in: Nanotechnology Vol. 35; no. 22; pp. 225604 - 225615
• Main Authors: Huang, Li, Wang, Pengkun, Yang, Hechuan, Wang, Yan, Cai, Wangfeng
• Format: Journal Article
• Language: English
• Published: England IOP Publishing 27.05.2024
• Subjects: core–shell structure; defect engineering; multifunctional; S doping; multifunctional; core–shell structure; S doping; defect engineering
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/1361-6528/ad26d8

In this study, S-CCO@Co(OH) ('CCO' representing CuCo O /Cu O; 'S-'representing sulfur doping) was synthesized by hydrothermal method followed by electrodeposition. The multiple effects of S doping were studied by S doping and constructing 3D core-shell structure. S doping induced the reduction of Cu and Co to Cu and Co , respectively. Also, S partially replaces O and creates oxygen vacancies, which increases a number of active sites for the redox reaction enhancing the redox reaction activity. After the electrodeposition, S-Co bond is formed between the Co(OH) shell and the S-CCO core, which suggests a synergistic effect between S doping and core-shell structure. The formation of S-Co bond is conducive to electron and ion transport, thus improving electrochemical performance. After modification, the specific capacitance of S-CCO@Co(OH) is 4.28 times higher than CCO, up to 1730 Fg . Furthermore, the assembled S-CCO@Co(OH) //activated carbon supercapacitor exhibits an energy density of 83.89 Whkg at 848.81 Wkg and a retention rate of 98.48% after 5000 charge and discharge cycles. Therefore, S doping and its mutual effect with the utilization of the core-shell structure considerably enhanced the electrochemical performance of the CCO-based electrodes, endowing its potential in further application.