Redox Charge Transfer Kinetics and Reversibility of VO 2 in Aqueous and Non-Aqueous Electrolytes of Na-Ion Storage

Energy & Environmental Materials

article

Sul Ki Park¹  Kang Ho Shin¹  Puritut Nakhanivej¹  Harpalsinh H. Rana¹  Ho Seok Park¹ 

[1] School of Chemical Engineering, College of Engineering, Sungkyunkwan University;Department of Engineering, University of Cambridge;Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology ,(SAIHST), Sungkyunkwan University;SKKU Advanced Institute of Nano Technology ,(SAINT), Sungkyunkwan University

关键词: aqueous electrolyte;    energy storage mechanism;    hierarchical structure;    nanorod;    sodium ion storage;   

DOI  :  10.1002/eem2.12238

来源: Wiley

【 摘 要 】

The deep understanding about the electrochemical behavior of the nanostructured electrode in electrolytes provides crucial insights for the rational design of electrode for sodium (Na)-ion storage system (NIS). Here, we report redox charge transfer kinetics and reversibility of VO 2 (B) nanorod electrodes in both aqueous and organic electrolytes for NIS. The as-synthesized VO 2 (B) nanorods show the reversible redox reaction with the higher specific and rate capacitances at high current density in aqueous electrolytes than in organic electrolytes. Temperature-dependent impedance measurements demonstrate the more facile interfacial charge transfer of Na ions into VO 2 (B) nanorods in aqueous electrolytes. The reversible evolution in oxidation state and chemical composition of VO 2 (B) nanorods is observed in aqueous electrolytes, as confirmed by ex situ XRD and ex situ X-ray photoelectron spectroscopy analyses. Given by the facile and reversible pseudocapacitive feature, the electrochemical performances of VO 2 (B) nanorods are further improved by constructing the hierarchical structure of the reduced graphene oxide-VO 2 composite for aqueous Na + ion storage.

【 授权许可】

Unknown