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Title: Growth mechanism and magnetic and electrochemical properties of Na{sub 0.44}MnO{sub 2} nanorods as cathode material for Na-ion batteries

Nanorods of Na{sub 0.44}MnO{sub 2} are a promising cathode material for Na-ion batteries due to their large surface area and single crystalline structure. We report the growth mechanism of Na{sub 0.44}MnO{sub 2} nanorods via solid state synthesis and their physical properties. The structure and the morphology of the Na{sub 0.44}MnO{sub 2} nanorods are investigated by X-ray diffraction (XRD), scanning and tunneling electron microscopy (SEM and TEM), and energy-dispersive X-ray (EDX) techniques. The growth mechanism of the rods is investigated and the effects of vapor pressure and partial melting of Na-rich regions are discussed. The magnetic measurements show an antiferromagnetic phase transition at 25 K and the μ{sub eff} is determined as 3.41 and 3.24 μ{sub B} from the χ–T curve and theoretical calculation, respectively. The electronic configuration and spin state of Mn{sup 3+} and Mn{sup 4+} are discussed in detail. The electrochemical properties of the cell fabricated using the nanorods are investigated and the peaks in the voltammogram are attributed to the diffusion of Na ions from different sites. Na intercalation process is explained by one and two Margules and van Laar models. - Highlights: • We synthesized Na{sub 0.44}MnO{sub 2} nanorods via a simple solid state reaction technique. •more » Our studies show that excess Na plays a crucial role in the nanorod formation. • Magnetization measurements show that Mn{sup 3+} ions are in LS and HS states. • The electrochemical properties of the cell fabricated using the nanorods are investigated. • Na intercalation process is explained by one and two Margules and van Laar models.« less
Authors:
;  [1] ;  [2] ; ;  [1] ; ;  [3] ;  [4]
  1. Physic Department, Inonu University, Malatya 44120 (Turkey)
  2. Scientific and Technological Research Center, Inonu University, 44120 (Turkey)
  3. Department of Materials Science and Engineering, Anadolu University, Eskisehir (Turkey)
  4. Department of Materials Science and Engineering, Afyon Kocatepe University, Afyon 3200 (Turkey)
Publication Date:
OSTI Identifier:
22476115
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Characterization; Journal Volume: 105; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; ANTIFERROMAGNETISM; CATHODES; DIFFUSION; ELECTRIC BATTERIES; ELECTROCHEMISTRY; ELECTRONIC STRUCTURE; MAGNETIZATION; MANGANATES; MONOCRYSTALS; NANOSTRUCTURES; SCANNING ELECTRON MICROSCOPY; SODIUM COMPOUNDS; SOLIDS; SURFACE AREA; SYNTHESIS; TRANSMISSION ELECTRON MICROSCOPY; TUNNEL EFFECT; X-RAY DIFFRACTION