National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, Japan.
Phys Chem Chem Phys. 2011 Oct 21;13(39):17615-24. doi: 10.1039/c1cp21910c. Epub 2011 Sep 1.
We describe a graphene and single-walled carbon nanotube (SWCNT) composite film prepared by a blending process for use as electrodes in high energy density supercapacitors. Specific capacitances of 290.6 F g(-1) and 201.0 F g(-1) have been obtained for a single electrode in aqueous and organic electrolytes, respectively, using a more practical two-electrode testing system. In the organic electrolyte the energy density reached 62.8 Wh kg(-1) and the power density reached 58.5 kW kg(-1). The addition of single-walled carbon nanotubes raised the energy density by 23% and power density by 31% more than the graphene electrodes. The graphene/CNT electrodes exhibited an ultra-high energy density of 155.6 Wh kg(-1) in ionic liquid at room temperature. In addition, the specific capacitance increased by 29% after 1000 cycles in ionic liquid, indicating their excellent cyclicity. The SWCNTs acted as a conductive additive, spacer, and binder in the graphene/CNT supercapacitors. This work suggests that our graphene/CNT supercapacitors can be comparable to NiMH batteries in performance and are promising for applications in hybrid vehicles and electric vehicles.
我们描述了一种通过混合工艺制备的石墨烯和单壁碳纳米管 (SWCNT) 复合薄膜，可作为高能密度超级电容器的电极。在水相和有机电解液中，使用更实际的两电极测试系统，单个电极分别获得了 290.6 F g(-1) 和 201.0 F g(-1) 的比电容。在有机电解液中，能量密度达到 62.8 Wh kg(-1)，功率密度达到 58.5 kW kg(-1)。与石墨烯电极相比，单壁碳纳米管的添加使能量密度提高了 23%，功率密度提高了 31%。石墨烯/CNT 电极在室温下的离子液体中表现出超高的能量密度 155.6 Wh kg(-1)。此外，在离子液体中经过 1000 次循环后，比电容增加了 29%，表明其具有优异的循环稳定性。SWCNTs 在石墨烯/CNT 超级电容器中充当导电添加剂、间隔物和粘结剂。这项工作表明，我们的石墨烯/CNT 超级电容器在性能上可以与 NiMH 电池相媲美，有望应用于混合动力汽车和电动汽车。
