Starfruit-like vanadium oxide with Co2+ pre-intercalation and amorphous carbon confinement as a superior cathode for supercapacitors

Yangyang Wang; Lin Xu; Zongyu Wang; Zepeng Pu; Yapeng Yuan; Xiaodong Li; Xuehua Liu; Aiping Fu; Yanhui Li; Hongliang Li

doi:10.1016/j.jcis.2022.04.143

Starfruit-like vanadium oxide with Co²⁺ pre-intercalation and amorphous carbon confinement as a superior cathode for supercapacitors

J Colloid Interface Sci. 2022 Sep 15:622:748-758. doi: 10.1016/j.jcis.2022.04.143. Epub 2022 Apr 29.

Authors

Yangyang Wang¹, Lin Xu¹, Zongyu Wang¹, Zepeng Pu¹, Yapeng Yuan¹, Xiaodong Li¹, Xuehua Liu¹, Aiping Fu², Yanhui Li³, Hongliang Li⁴

Affiliations

¹ Institute of Materials for Energy and Environment, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China.
² College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, China; State Key Laboratory of Bio-Fibers and Eco-Textile, Qingdao University, Qingdao 266071, China.
³ State Key Laboratory of Bio-Fibers and Eco-Textile, Qingdao University, Qingdao 266071, China; College of Electromechanic Engineering, Qingdao University, Qingdao 266071, China.
⁴ Institute of Materials for Energy and Environment, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China; State Key Laboratory of Bio-Fibers and Eco-Textile, Qingdao University, Qingdao 266071, China. Electronic address: lhl@qdu.edu.cn.

PMID: 35537225
DOI: 10.1016/j.jcis.2022.04.143

Abstract

The vanadium dioxide (VO₂(D)), with ultra-high theoretical capacitance, has been considered as a boon for electrode materials of advanced supercapacitors (SCs). However, the VO₂ has a series of shortcomings such as poor electrical conductivity, severe structural damage, and rapid capacity fading during cycles, resulting in unsatisfactory electrochemical performance. Herein, the Co²⁺ pre-intercalation and amorphous carbon confined vanadium dioxide (CoxVO₂@C) with starfruit-like nanostructure is synthesized on a conductive Ni foam substrate via a versatile and cost-effective method. As a cathode for SCs, the obtained CoxVO₂@C not only enables a small amount of Co²⁺ pre-intercalation layer to offer faster ion diffusion kinetics for VO₂, but also utilizes a high-conductivity amorphous carbon to protect VO₂ from dissolution in an alkaline electrolyte, thereby exhibiting the ultrahigh specific capacitance up to 4440.0 mF cm^-2 at 5 mA cm^-2 (525.2 F g^-1 at 2 A g^-1) and the prominent long-term stability performance of the electrode. Benefited from these excellent characteristics, a high-performance CoxVO₂@C//V₂O₃ hybrid supercapacitor (HSC) device with an operating voltage of 1.7 V is further assembled. The HSC device delivers a superior energy density of 102.3 W h kg^-1 at a power density of 6.1 kW kg^-1, manifesting its practical feasibility.

Keywords: Amorphous carbon confinement; Co(2+) pre-intercalation; Starfruit-like nanostructure; Supercapacitor; Vanadium oxide.