کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6471602 | 1424122 | 2017 | 8 صفحه PDF | دانلود رایگان |
Hierarchical porous carbon spheres/graphene (CSG) composite was prepared by a simple self-assembled method for supercapacitor electrode materials. Carbon spheres (CS) was chosen as the spacer for graphene due to its submicron size. The morphology and structure of as-prepared samples were characterized by SEM, XRD and N2 adsorption/desorption techniques. As a result, the aggregation of graphene was reduced by CS effectively, which leads to an enhanced specific surface area and more ion-accessible pores. This unique structure is conducive to the penetration/mobility of ions, especially for ionic liquid with large ionic sizes. The electrochemical performance of synthesized CSG was investigated and the composite offered an outstanding capacitive behavior. In the two-electrode system, CSG electrode displayed a specific capacitance of 303.8 F gâ1 in KOH and 280.0 F gâ1 in [BMIM]BF4. Remarkably, the CSG//CSG supercapacitor exhibited a high energy density of 87.5 Wh kgâ1 in [BMIM]BF4 electrolyte. After 5000 cycles, the specific capacitance of CSG could still remain 95.3% in KOH and 90.1% in [BMIM]BF4 of the initial value, implying good long-term cycle stability of the composite. The outstanding electrochemical performance can be attributed to the novel hierarchical porous structure.
Journal: Electrochimica Acta - Volume 235, 1 May 2017, Pages 340-347