Fabrication of CoSe2/CoP with rich selenium- and phosphorus-vacancies and heterogeneous interfaces for asymmetric supercapacitors

Xingyue Wu; Yiping Qiu; Baozhu Yang; Junyao Li; Wenrong Cai; Yong Qin; Yong Kong; Zheng-Zhi Yin

doi:10.1016/j.jcis.2023.07.191

Fabrication of CoSe₂/CoP with rich selenium- and phosphorus-vacancies and heterogeneous interfaces for asymmetric supercapacitors

J Colloid Interface Sci. 2023 Dec:651:128-137. doi: 10.1016/j.jcis.2023.07.191. Epub 2023 Jul 31.

Authors

Xingyue Wu¹, Yiping Qiu¹, Baozhu Yang¹, Junyao Li¹, Wenrong Cai¹, Yong Qin¹, Yong Kong², Zheng-Zhi Yin³

Affiliations

¹ Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China.
² Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China. Electronic address: yzkongyong@cczu.edu.cn.
³ College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing 314001, China. Electronic address: yinzhengzhi@zjxu.edu.cn.

PMID: 37542888
DOI: 10.1016/j.jcis.2023.07.191

Abstract

CoSe₂/CoP with rich Se- and P-vacancies and heterogeneous interfaces (v-CoSe₂/CoP) is grown on the surface of nickel foam via a two-step strategy: electrodeposition and NaBH₄ reduction, which can be used as the cathode material in asymmetric supercapacitors. The SEM characterization reveals the honeycomb-like structure of the v-CoSe₂/CoP, and the results of EPR, XPS and HRTEM reveal the existence of anionic vacancies and heterogeneous interfaces in the v-CoSe₂/CoP. The as-fabricated v-CoSe₂/CoP exhibits high specific capacitance (3206 mF cm^-2 at 1.0 mA cm^-2) and cyclic stability (91 % capacitance retention after 2000 cycles). An asymmetric supercapacitor is assembled by using the v-CoSe₂/CoP and activated carbon (AC) as cathode and anode materials, respectively, which displays a high energy density of 40.6 Wh kg^-1 at the power density of 211.5 W kg^-1. The outstanding electrochemical performances of the v-CoSe₂/CoP might be ascribed to the synergistic effects of Se- and P-vacancies and the heterogeneous interfaces in the v-CoSe₂/CoP.

Keywords: Anionic vacancies; Asymmetric supercapacitors; CoSe(2)/CoP; Density of states; Heterogeneous interfaces.