High-performance asymmetrical supercapacitor composed of rGO-enveloped nickel phosphite hollow spheres and N/S co-doped rGO aerogel
nickel phosphate, hollow sphere, graphene, nitrogen/sulfur co-doping, asymmetrical, supercapacitor
ABSTRACT An asymmetrical supercapacitor (ASC), comprising reduced graphene oxide (rGO)-encapsulated nickel phosphite hollow microspheres (NPOH-0.5@rGO) as positive electrode, and porous nitrogen/sulfur co-doped rGO aerogel (NS-3D rGO) as negative electrode has been prepared. The NPOH-0.5@rGO electrode combines the advantages of the NPOH hollow microspheres and the conductive rGO layers giving rise to a large specific capacitance, high cycling reversibility, and excellent rate performance. The NS-3D rGO electrode with abundant porosity and active sites promotes electrolyte infiltration and broadens the working voltage range. The ASC (NPOH-0.5@rGO//NS-3D rGO) shows a maximum voltage of up to 1.4 V, outstanding cycling ability (capacitance retention of 95.5% after 10,000 cycles), and excellent rate capability (capacitance retention of 77% as the current density is increased ten times). The ASC can light up an light-emitting diodes (LED) for more than 20 min after charging for 20 s. The fabrication technique and device architecture can be extended to other active oxide and carbon-based materials for next-generation high-performance electrochemical storage devices.
Tsinghua University Press
Deyang Zhang,Yihe Zhang,Yongsong Luo,Yu Zhang,Xiaowei Li,Xuelian Yu,Hao Ding,Paul K. Chu,Li Sun, High-performance asymmetrical supercapacitor composed of rGO-enveloped nickel phosphite hollow spheres and N/S co-doped rGO aerogel. NanoRes.2018, 11(3): 1651–1663