MnO2-coated graphitic petals for supercapacitor electrodes
MnO2-coated graphitic petals for supercapacitor electrodes
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DOI：
10.1016/j.jpowsour.2012.11.040
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发表时间：
2013-04-01
影响因子：
9.2
通讯作者：
Fisher, Timothy S.
中科院分区：
文献类型：
--
作者：
Xiong, Guoping;Hembram, K. P. S. S.;Fisher, Timothy S.
在碳纳米管衬底上生长的混合二氧化锰/石墨花瓣结构显示出对于柔性超级电容器应用实现高比电容、能量密度、功率密度和长循环寿命。采用微波等离子体化学气相沉积法在商用碳纳米管基底上制备了垂直的纳米级石墨花瓣，并在其表面涂覆了一层MnO 2薄膜。不含任何粘合剂的石墨花瓣/碳纳米管结构为最大限度地提高MnO 2的电化学性能提供了有效的支架。在1 M Na 2SO 4水溶液中，以2 mV s（-1）的扫描速率扫描时，获得了580 F g（-1）的比电容（基于MnO 2的质量）。在50 A g（-1）下的能量密度和功率密度分别为28 Wh kg（-1）和25 kW kg（-1）。此外，该复合电极显示出优异的长期循环稳定性（1000次循环后比电容降低小于10%），同时保持小的内阻。平行密度泛函研究进行了调查的MnO 2/石墨烯界面的稳定性和电子结构。综上所述，工作表明MnO 2/石墨花瓣/碳纳米管复合材料是一种有前途的高性能超级电容器电极材料。(C)2012爱思唯尔有限公司版权所有。
Hybrid manganese dioxide/graphitic petal structures grown on carbon nanotube substrates are shown to achieve high specific capacitance, energy density, power density, and long cycle life for flexible supercapacitor applications. Vertical nanoscale graphitic petals were prepared by microwave plasma chemical vapor deposition on commercial carbon nanotube substrates and subsequently coated with a thin layer of MnO2. The graphitic petal/carbon nanotube architecture without any binder provides an efficient scaffold for maximizing the electrochemical performance of MnO2. A specific capacitance (based on the mass of MnO2) of 580 F g(-1) is obtained at a scan rate of 2 mV s(-1) in 1 M Na2SO4 aqueous electrolyte. The energy density and power density at 50 A g(-1) are 28 Wh kg(-1) and 25 kW kg(-1), respectively. In addition, the composite electrode shows excellent long-term cyclic stability (less than 10% decrease in specific capacitance after 1000 cycles) while maintaining a small internal resistance. Parallel density functional studies were performed to investigate the stability and electronic structure of the MnO2/graphene interface. Taken together, the work indicates the MnO2/graphitic petal/carbon nanotube composite is a promising electrode material for high-performance supercapacitors. (C) 2012 Elsevier B.V. All rights reserved.