Flexible Zn2SnO4/MnO2 Core/Shell Nanocable−Carbon Microfiber Hybrid Composites for High-Performance Supercapacitor Electrodes

• Published in: Nano letters Vol. 11; no. 3; pp. 1215 - 1220
• Main Authors: Bao, Lihong, Zang, Jianfeng, Li, Xiaodong
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 09.03.2011
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials science; Methods of nanofabrication; Physics; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); MnO2; Supercapacitor; Zn2SnO4 nanowire; carbon microfiber; flexible; composite; High density; Core shell structure; Thick films; Energy density; Nanocable; Nanostructures; Coatings; Carbon; Cyclic voltammetry; Nanometer scale; Manganese oxides; Composite materials; Aqueous solutions; High energy; Zinc Stannates; Capacitance; Surface area; Current density; Nanomaterial synthesis
• ISSN: 1530-6984; 1530-6992; 1530-6992
• DOI: 10.1021/nl104205s

We demonstrate the design and fabrication of a novel flexible nanoarchitecture by facile coating ultrathin (several nanometers thick) films of MnO2 to highly electrical conductive Zn2SnO4 (ZTO) nanowires grown radially on carbon microfibers (CMFs) to achieve high specific capacitance, high-energy density, high-power density, and long-term life for supercapacitor electrode applications. The crystalline ZTO nanowires grown on CMFs were uniquely served as highly conductive cores to support a highly electrolytic accessible surface area of redox active MnO2 shells and also provide reliable electrical connections to the MnO2 shells. The maximum specific capacitances of 621.6 F/g (based on pristine MnO2) by cyclic voltammetry (CV) at a scan rate of 2 mV/s and 642.4 F/g by chronopotentiometry at a current density of 1 A/g were achieved in 1 M Na2SO4 aqueous solution. The hybrid MnO2/ZTO/CMF hybrid composite also exhibited excellent rate capability with specific energy of 36.8 Wh/kg and specific power of 32 kW/kg at current density of 40 A/g, respectively, and good long-term cycling stability (only 1.2% loss of its initial specific capacitance after 1000 cycles). These results suggest that such MnO2/ZTO/CF hybrid composite architecture is very promising for next generation high-performance supercapacitors.