Pseudocapacitive NiO Fine Nanoparticles for Supercapacitor Reactions

• Published in: Journal of the Electrochemical Society Vol. 159; no. 10; pp. A1598 - A1603
• Main Authors: Yeager, Matthew P., Su, Dong, Marinković, Nebojsa S., Teng, Xiaowei
• Format: Journal Article
• Language: English
• Published: United States The Electrochemical Society 01.01.2012
• Subjects: 29; electrochemical; functional nanomaterials; in situ XANES; NiO; Supercapacitor
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/2.025210jes

We report nickel oxide (NiO) fine nanoparticles with an average diameter of 5.3 ± 1.3 nm as an electrode material for supercapacitor reactions. The superior pseudocapacitive behavior of NiO nanoparticles was demonstrated in three-electrode half-cells and two-electrode button cells, with a maximum specific capacitance of 243 F/g. In situ X-ray absorption near edge structure spectroscopy was used for the first reported time to study the evolution of the electronic structures of NiO during the charge-transfer reactions. We observed that a predominant change of valence state occurred between 0.35 V and 0.50 V (vs. Hg/HgO). The development of NiO nanomaterials in the present study provides a new approach in fabricating advanced pseudocapacitors by utilizing highly cost-effective transition metal oxide electrode materials.