Ultrafine manganese dioxidenanowire network for high-performance supercapacitors

Abstract

Ultrafine MnO(2) nanowires with sub-10 nm diameters have been synthesized by a simple process of hydrothermal treatment with subsequent calcinations to form networks that exhibit an enhanced specific capacitance (279 F g(-1) at 1 A g(-1)), high rate capability (54.5% retention at 20 A g(-1)) and good cycling stability (1.7% loss after 1000 cycles).

High-performance α-MnO2 nanowire electrode for supercapacitors

“…Therefore, the bulk materials with well-developed interconnectivity would be helpful in terms of the ion transfer of the electrolyte [43]. The open spaces between the individual nanowires could facilitate the electrolyte penetration into the inner region of electrodes, and the 1-D nanowire structure with high surface area could also shorten the diffusion paths for both electrons and ions with the oxide, and provide more active sites for electrochemical rections [31,28]. The large tunnels in the crystal structure of a-MnO2/CFP electrode might facilitate the intercalation and deintercalation of cations into the bulk of the oxide.…”

“…It is believed that one-dimensional (1-D) nanostructures with controlled size and crystallinity could provide additional electroactive sites, shorten ion/electron diffusion lengths, and then enhance the mechanical property of the electrodes. Regarding this, a variety of 1-D nanostructured MnO 2 such as nanoparticles, nanotubes and nanowires have been successfully fabricated with enhanced electrochemical performances [24][25][26][27][28]. In the electrode application of nanomaterials, most of these materials are powders, which may not well utilize the advantage and also restrict the applicability of 1-D nanostructured materials such as MnO 2 .…”

Recent Progress on Electrochemical Capacitors Based on Carbon Nanotubes

“…The most promising among them is manganese dioxide MnO 2 because of its low cost, environmental compatibility, natural abundance, high energy density, and excellent capacitive performance in aqueous electrolytes [32,[135][136][137][138][139][140][141][142][143]. In aqueous electrolytes, the charging mechanism of MnO 2 may be described by the following reaction: .…”

Novel synthesis and formation process of uniform Mn2O3 cubes

“…[5][6][7] Among the transition metal oxides, manganese oxides are given wide attention because of their special physical and chemical properties and potential applications in catalysis, ion exchange, molecular adsorption, and energy storage in lithium ion secondary battery and supercapacitor. [8][9][10][11][12] Research results show that the morphology of manganese oxides connects with their surface area, density, and surface to volume ratio, which have an obvious effect on their physical and chemical properties. [9][10][11] Therefore, the controllable fabrication of the manganese-based materials with different morphologies is important from the viewpoint of the foundational research and technological application.…”

“…Many efforts have been devoted to the synthesis of manganese-based materials with different morphologies. [12][13][14][15] Mn 2 O 3 is a traditionally attractive material for various industrial applications, such as a cheap and environmentally-friendly catalyst for removing carbon monoxide and nitrogen oxide from waste gas, [16][17][18] the precursor for producing soft magnetic materials, 19 and the electrode material of rechargeable lithium batteries. 20 Up to now, a wide variety of Mn 2 O 3 with different morphologies, ranging from one to three-dimensional structures, such as rods, wires, cubes, octahedra, and hollow spheres, have been synthesized through various methods.…”