Building 3D Structures of Vanadium Pentoxide Nanosheets and Application as Electrodes in Supercapacitors

作者：Zhu, Jixin; Cao, Liujun; Wu, Yingsi; Gong, Yongji; Liu, Zheng; Hoster, Harry E.; Zhang, Yunhuai; Zhang, Shengtao; Yang, Shubin^*; Yan, Qingyu; Ajayan, Pulickel M.; Vajtai, Robert

来源：Nano Letters, 2013, 13(11): 5408-5413.

DOI：10.1021/nl402969r

• 2D layers
• V2O5
• 3D architectures
• high energy density
• supercapacitor

Various two-dimensional (2D) materials have recently attracted great attention owing to their unique properties and wide application potential in electronics, catalysis, energy storage, and conversion. However, large-scale production of ultrathin sheets and functional nanosheets remains a scientific and engineering challenge. Here we demonstrate an efficient approach for large-scale production of V2O5 nanosheets having a thickness of 4 nm and utilization as building blocks for constructing 3D architectures via a freeze-drying process. The resulting highly flexible V2O5 structures possess a surface area of 133 m(2) g(-1), ultrathin walls, and multilevel pores. Such unique features are favorable for providing easy access of the electrolyte to the structure when they are used as a supercapacitor electrode, and they also provide a large electroactive surface that advantageous in energy storage applications. As a consequence, a high specific capacitance of 451 F g(-1) is achieved in a neutral aqueous Na2SO4 electrolyte as the 3D architectures are utilized for energy storage. Remarkably, the capacitance retention after 4000 cycles is more than 90%, and the energy density is up to 107 W.h.kg(-1) at a high power density of 9.4 kW kg(-1).

• 出版日期2013-11
• 单位重庆大学