二氧化钌/石墨烯复合材料超级电容器的性能

Performances of RuO_2/Graphene Composites as the Supercapacitor

通过溶胶-凝胶法和低温煅烧法,成功制备了二氧化钌/石墨烯纳米复合材料,并用XPS、TEM和XRD检测了产物形貌、粒径及晶型。实验表明,在复合材料中,水合二氧化钌颗粒呈球形,粒径约为5 nm,并均匀分散在石墨烯表面。该材料用于超级电容器中,表现出了良好的电容性质。当二氧化钌的质量分数为38%时,二氧化钌在复合材料中的比电容为546.6 F.g-1。较之二氧化钌,二氧化钌/石墨烯复合材料还表现出了更快的倍率性能、更出色的电化学稳定性(循环1 000圈后大约保持93%)以及更高的能量密度(26.5 W.h.kg-1)和功率密度(5 000 W.kg-1)。该复合材料不仅具备了石墨烯双电层电容的优点,而且还具备了二氧化钌赝电容的性质,是一种良好的储能材料。

RuO2/grapheme （RuO2/GR） nanocomposites with different loadings of RuO2 were pre- pared by sol-gel and low-temperature annealing processes. XPS, TEM and XRD were used to examine the morphology, grain size and crystalline type of the synthesized material. The experi- ment results show that the RuO2 nanoparticles in the nanocomposite with the diameter of about 5 nm are homogeneously deposited on the surface of GR. The supercapacitor based on the RuO2/ GR nanocomposite shows good supercapacitive behaviors. When the loading level of RuO2 reaches 38%, the RuO2 nanoparticles in the nanocomposite achieve a specific capacitance of 546.6 F·g-1. Compared with the bare RuO2, the RuO2/GR nanocomposite also exhibits the enhanced rate capability,more excellent electrochemical stability （about 93% retention after 1 000 cycles）, higher energy density （26.5 W. h. kg-1） at low operation rate and higher power density （5000W·kg^-1） at a reasonable energy density. The RuO2/GR nanocomposite could fully utilize the advantages of GR as double-layer capacitors and RuO2 as pseudoeapacitors, which proves that it is a good mate- rial for the energy storage.