Ultrathin Co3O4 nanosheet arrays with high supercapacitive performance

• Published in: Scientific reports 2013-12, Vol.3 (1), p.3537, Article 3537
• Main Authors: Yang, Qiu, Lu, Zhiyi, Sun, Xiaoming, Liu, Junfeng
• Format: Article
• Language: English
• Subjects: 639/301/299; 639/301/357/1018; 639/638/298; Capacitance; Electrodes; Humanities and Social Sciences; multidisciplinary; Science
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep03537

Constructing nanostructures with desirable morphology and size is a critical issue for pursuing high performance electrode materials. Ultrathin Co 3 O 4 nanosheet arrays, which are composed of well aligned uniform long-range (~5 μm in length) and thin (~10 nm in thickness) nanosheets, with reasonable mass loading on Ni foam are prepared by a two-step hydrothermal reaction. As a supercapacitor electrode, a superior specific capacitance (~1782 F g −1 ) is obtained at current density of 1.8 A g −1 (5 mA cm −2 ), much larger than that of the thicker nanostrucutures (~300 F g −1 ). The ultrathin nanosheet arrays electrode exhibits good rate capabilities, maintaining 51% of the initial capacity at current density of 30 mA cm −2 and excellent long-term stability, remaining >90% of capacitance after 2000 cycles. Such high performance is attributed to the desirable morphologies, uniform architecture and high surface area. The results manifest that ultrathin Co 3 O 4 nanosheet arrays are promising electrode material for supercapacitor in future application.