Synergistic Effects from Graphene and Carbon Nanotubes Enable Flexible and Robust Electrodes for High-Performance Supercapacitors

• Published in: Nano letters Vol. 12; no. 8; pp. 4206 - 4211
• Main Authors: Cheng, Yingwen, Lu, Songtao, Zhang, Hongbo, Varanasi, Chakrapani V, Liu, Jie
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 08.08.2012
• Subjects: Applied sciences; Capacitors; Cross-disciplinary physics: materials science; rheology; Density; Devices; Electrodes; Electronics; Energy storage; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; Graphene; Materials; Materials science; Molecular electronics, nanoelectronics; Nanoscale materials and structures: fabrication and characterization; Nanotubes; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Specific materials; Supercapacitors; Synergistic effect; MnO2; carbon nanotubes; graphene; flexible energy storage; supercapacitor; Potential energy; Display devices; Mechanical strength; Carbon nanotubes; Mechanical properties; Tensile strength; Nanoelectronics; Thin films; Manganese oxides; Electrochemical properties; Nanocomposites; Graphene; Capacitance; Active material; Nanostructured materials; Tensile properties
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl301804c

Flexible and lightweight energy storage systems have received tremendous interest recently due to their potential applications in wearable electronics, roll-up displays, and other devices. To manufacture such systems, flexible electrodes with desired mechanical and electrochemical properties are critical. Herein we present a novel method to fabricate conductive, highly flexible, and robust film supercapacitor electrodes based on graphene/MnO2/CNTs nanocomposites. The synergistic effects from graphene, CNTs, and MnO2 deliver outstanding mechanical properties (tensile strength of 48 MPa) and superior electrochemical activity that were not achieved by any of these components alone. These flexible electrodes allow highly active material loading (71 wt % MnO2), areal density (8.80 mg/cm2), and high specific capacitance (372 F/g) with excellent rate capability for supercapacitors without the need of current collectors and binders. The film can also be wound around 0.5 mm diameter rods for fabricating full cells with high performance, showing significant potential in flexible energy storage devices.