Chem. J. Chinese Universities ›› 2026, Vol. 47 ›› Issue (10): 20260201.doi: 10.7503/cjcu20260201

• Physical Chemistry • Previous Articles     Next Articles

Cobalt Single-atom Sites for Kinetically Enhanced Rate Performance of Carbon-based Supercapacitor Electrodes

YANG Shaoqing1,2, ZHANG Hao2(), ZHANG Hanming3, ZHANG Wangzhi3, ZHANG Haitao1,2(), LUO Jun1,2()   

  1. 1.University of Electronic Science and Technology of China,Chengdu 611731,China
    2.Shenzhen Institute for Advanced Study,University of Electronic Science and Technology of China,Shenzhen 518110,China
    3.Oil & Gas Technology Research Institute of Qinghai Oilfield Company,Jiuquan 736202,China
  • Received:2026-05-13 Online:2026-10-10 Published:2026-06-12
  • Contact: ZHANG Hao, ZHANG Haitao, LUO Jun E-mail:zhanghao@uestc.edu.cn;zhanght15@tsinghua.org.cn;jluo@uestc.edu.cn
  • Supported by:
    the Natural Science Foundation of Chongqing City, China(CSTB2022NSCQ-MSX1101)

Abstract:

To elucidate the influence of adjacent transition-metal single-atom sites on the energy-storage kinetics of carbon-based supercapacitor electrodes, Fe and Co single-atom-modified nitrogen-doped carbon materials, denoted as Fe@NC and Co@NC, were prepared using activated carbon as the carbon substrate via a metal-ligand coordination and carbonization strategy. Nitrogen-doped carbon without metal single-atom sites was used as the control sample. Structural characterizations reveal that NC, Fe@NC, and Co@NC possess similar carbon frameworks and porous structures, while Fe and Co species are highly dispersed and anchored in the nitrogen-doped carbon matrix, forming M-N4 coordination configurations. Electrochemical measurements show that Fe@NC and Co@NC deliver higher specific capacitances than NC, indicating that the introduction of metal single-atom sites can improve the charge-storage capability of carbon-based electrodes. Fe@NC and Co@NC exhibit comparable specific capacitances at current density of 1 A/g, with values of 106 and 109 F/g, respectively. When the current density increases to 20 A/g, Co@NC retains 55% of its capacitance, markedly higher than Fe@NC(38%), suggesting that Co single-atom sites are more favorable for improving high-rate capacitance retention. Further kinetic analyses demonstrate that Co@NC possesses a higher capacitive-controlled contribution, lower charge-transfer resistance, and more favorable ion-diffusion behavior, indicating that Co single-atom sites are more effective in facilitating rapid charge/ion transport. These results reveal that the rate-performance enhancement of carbon-based supercapacitor electrodes induced by metal single-atom sites mainly originates from optimized electrochemical kinetics, with Co single-atom sites showing greater advantages in promoting fast energy storage. This study provides mechanistic insight into the regulation of rate performance in carbon-based supercapacitor electrodes through single-atom site engineering.

Key words: Single atom, Carbon-based electrode material, Supercapacitor, Electrochemical kinetics, Rate performance

CLC Number: 

TrendMD: