Micro-Supercapacitors Based on Interdigital Electrodes of Reduced Graphene Oxide and Carbon Nanotube Composites with Ultrahigh Power Handling Performance
Micro-Supercapacitors Based on Interdigital Electrodes of Reduced Graphene Oxide and Carbon Nanotube Composites with Ultrahigh Power Handling Performance
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DOI：
10.1002/adfm.201201292
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发表时间：
2012-11-07
影响因子：
19
通讯作者：
Wang, Chunlei
中科院分区：
文献类型：
--
作者：
Beidaghi, Majid;Wang, Chunlei
报道了一种基于还原氧化石墨烯（rGO）和碳纳米管（CNT）复合材料的用于超高功率处理的微型超级电容器应用的微图案化叉指电极的新方法。结合静电喷雾沉积（ESD）和光刻剥离方法，开发了无粘合剂微电极。在没有通常使用的热还原或化学还原的情况下，GO片在ESD沉积期间容易还原成rGO。电化学测量表明，微电极的平面内叉指设计在通过电活化过程增加堆叠的rGO片之间的电解质离子的可及性方面是有效的。CNT的添加导致rGO片的减少的重新堆叠和改进的能量和功率密度。循环伏安法（CV）测量表明，基于rGOCNT复合材料的微型超级电容器在0.01 V s（-1）下的比电容为6.1 mF cm（-2）。在50 V s（-1）的非常高的扫描速率下，记录到2.8 mF cm（-2）的比电容（3.1 F cm（-3）的堆叠电容），这是超级电容器前所未有的性能。此外，碳纳米管，电解质可访问和无粘合剂的微电极，以及叉指在平面内的设计结果在高频响应的微型超级电容器的电容时间常数低至4.8毫秒。这些特性表明，叉指rGOCNT复合电极是有前途的芯片上的能量存储应用与高功率需求。
A novel method for fabricating micro-patterned interdigitated electrodes based on reduced graphene oxide (rGO) and carbon nanotube (CNT) composites for ultra-high power handling micro-supercapacitor application is reported. The binder-free microelectrodes were developed by combining electrostatic spray deposition (ESD) and photolithography lift-off methods. Without typically used thermal or chemical reduction, GO sheets are readily reduced to rGO during the ESD deposition. Electrochemical measurements show that the in-plane interdigital design of the microelectrodes is effective in increasing accessibility of electrolyte ions in-between stacked rGO sheets through an electro-activation process. Addition of CNTs results in reduced restacking of rGO sheets and improved energy and power density. Cyclic voltammetry (CV) measurements show that the specific capacitance of the micro-supercapacitor based on rGOCNT composites is 6.1 mF cm(-2) at 0.01 V s(-1). At a very high scan rate of 50 V s(-1), a specific capacitance of 2.8 mF cm(-2) (stack capacitance of 3.1 F cm(-3)) is recorded, which is an unprecedented performance for supercapacitors. The addition of CNT, electrolyte-accessible and binder-free microelectrodes, as well as an interdigitated in-plane design result in a high-frequency response of the micro-supercapacitors with resistive-capacitive time constants as low as 4.8 ms. These characteristics suggest that interdigitated rGOCNT composite electrodes are promising for on-chip energy storage application with high power demands.