Carbon nanotubes and manganese oxide hybrid nanostructures as high performance fiber supercapacitors

Abstract

Manganese oxide (MnO 2 ) has long been investigated as a pseudo-capacitive material for fabricating fiber-shaped supercapacitors but its poor electrical conductivity and its brittleness are clear drawbacks. Here we electrochemically insert nanostructured MnO 2 domains into continuously interconnected carbon nanotube (CNT) networks, thus imparting both electrical conductivity and mechanical durability to MnO 2 . In particular, we synthesize a fiber-shaped coaxial electrode with a nickel fiber as the current collector (Ni/CNT/MnO 2 ); the thickness of the CNT/MnO 2 hybrid nanostructured shell is approximately 150 μm and the electrode displays specific capacitances of 231 mF cm −1 . When assembling symmetric devices featuring Ni/CNT/MnO 2 coaxial electrodes as cathode and anode together with a 1.0 M Na 2 SO 4 aqueous solution as electrolyte, we find energy densities of 10.97 μWh cm −1 . These values indicate that our hybrid systems have clear potential as wearable energy storage and harvesting devices.

Manganese oxide synthesized from spent Zn-C battery for supercapacitor electrode application

“…with high surface area are used. Besides, in pseudo-capacitance mechanism, energy density is governed by reversible redox interactions of the active materials as electrode and generally transition metal oxides and conducting polymers are used as active materials 1,4,5 . Nanostructured metal oxides as electrode material, have attracted attention due to design flexibility, low resistance and high specific capacitance 6 .…”

Synthesis and Characterization of Nickel-doped Manganese Dioxide Electrode Materials for Supercapacitors

“…In order to increase the specific capacitance of the MnO 2 electrode materials, MnO 2 is usually compounded with other materials such as carbon materials or conductive polymers. [11][12][13] In addition, doping the transition metal element in the MnO 2 lattice is also an effective method to improve the electrochemical performance of the electrode materials. [8,14] In this paper, Ni-MnO2 electrode materials were synthesized by sol-gel method with nickel nitrate, manganese acetate and citric acid as raw materials.…”

The nature of small molecules adsorbed on defective carbon nanotubes

“…Carbon nanotubes (CNTs), which were discovered in 1991 [1,2], have attracted enduring attention due to their unique structural, thermal, electronic and dynamic properties, which facilitate the use of CNTs in promising medical and biochemical applications. In fact, CNTs have already found applications in many fields, including hydrogen storage [3], free-radicals scavenging activity [4], chemical sensors [5], nanobiology electronics [6], functional groups adsorption substrates [7], capacitors [8] and the like.…”