Co3O4 Nanorods with Self-assembled Nanoparticles in Queue for Supercapacitor

• Published in: Electrochimica acta 2015-10, Vol.180, p.104-111
• Main Authors: Meng, Tao, Xu, Qian-Qian, Wang, Zhi-Hong, Li, Yin-Tao, Gao, Ze-Min, Xing, Xiang-Ying, Ren, Tie-Zhen
• Format: Article
• Language: English
• Subjects: Co3O4 nanorods; organic molecules; self-assemble; supercapacitor
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2015.08.085

The Co3O4 nanorods are obtained by facile calcinations of Co-composites. SEM and TEM studies reveal that the nanoparticles in 20–40nm scales are arranged in queue to form the nanorods. The Co3O4 nanorods show the highest specific capacity of 262Fg−1 at 5mVs−1 in the range of 0.2–0.7V (vs. Ag/AgCl) and a good cycle life with nearly no decrease after 500 cycles at 50mVs−1. The asymmetrical Co3O4//AC button cell has a power density of 1.69kWkg−1 with a high energy density of 42.81Whkg−1 when the discharge current is 1.5Ag−1 and the potential window is 1.5V. [Display omitted] •The Co3O4 nanorods are easily derived from the Co-composites.•The Co3O4 nanorods are composed of nanoparticles in queue.•The energy density achieves to 48WhKg−1 at the discharge current of 1.5Ag−1. Co3O4 nanorods are prepared by a facile calcinations of the Co-composites, which is synthesized with the precursors of CoCl2, 1,3,5-Benzenetri carboxylic acid (H3BTC) and phenanthroline (PHEN). The Co-composites nonorods are about 1 um long and 50nm wide. After calcinations, the Co3O4 nanorods are composed of nanoparticles of 20–40nm in queue and possesses a surface area of 23m2g−1 owning to the release of the organic molecules. The electrochemical properties are examined by cyclic voltammetry, electrochemical impedance spectroscopy and cyclic charge-discharge tests. The results show that the Co3O4 have the highest specific capacity of 262Fg−1 at 5mVs−1 in the range of 0.2–0.7V (vs. Ag/AgCl) and have a good cycle life with nearly no decrease after 500 cycles at 50mVs−1. The asymmetrical Co3O4//AC button cell is also tested by two-electrode system with a large potential testing window of 1.5V and the results show the high energy density with a value of 42.81Whkg−1 at the discharge current of 1.5Ag−1.