Enhancing the Supercapacitor Performance of Graphene/MnO2 Nanostructured Electrodes by Conductive Wrapping
Enhancing the Supercapacitor Performance of Graphene/MnO2 Nanostructured Electrodes by Conductive Wrapping
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DOI：
10.1021/nl2026635
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发表时间：
2011-10-01
期刊：
影响因子：
10.8
通讯作者：
Bao, Zhenan
中科院分区：
文献类型：
--
作者：
Yu, Guihua;Hu, Liangbing;Bao, Zhenan
MnO 2具有理论比容量高、成本低、环境友好和天然丰富等优点，被认为是最有前途的高性能超级电容器赝电容材料之一。然而，MnO 2电极通常具有较差的电子和离子电导率，导致其在功率密度和循环方面的有限性能。在这里，我们开发了一种“导电包裹”方法，以大大提高石墨烯/MnO 2基纳米结构电极的超级电容器性能。通过用碳纳米管或导电聚合物对石墨烯/MnO 2纳米结构进行三维（3D）导电包裹，电极的比电容（考虑活性材料的总质量）分别大幅增加了约20%和约45%，达到了约380 F/g的值。此外，这些三元复合电极还表现出优异的循环性能，在3000次循环中具有>95%的电容保持率。这种3D导电包裹方法代表了增强基于金属氧化物的电化学超级电容器的器件性能的令人兴奋的方向，并且可以推广用于设计下一代高性能储能器件。
MnO2 is considered one of the most promising pseudocapactive materials for high-performance supercapacitors given its high theoretical specific capacitance, low-cost, environmental benignity, and natural abundance. However, MnO2 electrodes often suffer from poor electronic and ionic conductivities, resulting in their limited performance in power density and cycling. Here we developed a "conductive wrapping" method to greatly improve the supercapacitor performance of graphene/MnO2-based nanostructured electrodes. By three-dimensional (3D) conductive wrapping of graphene/MnO2 nanostructures with carbon nanotubes or conducting polymer, specific capacitance of the electrodes (considering total mass of active materials) has substantially increased by similar to 20% and similar to 45%, respectively, with values as high as similar to 380 F/g achieved. Moreover, these ternary composite electrodes have also exhibited excellent cycling performance with >95% capacitance retention over 3000 cycles. This 3D conductive wrapping approach represents an exciting direction for enhancing the device performance of metal oxide-based electrochemical supercapacitors and can be generalized for designing next-generation high-performance energy storage devices.