A Sodium Manganese Oxide Cathode by Facile Reduction for Sodium Batteries. Issue 6 (1st April 2014)

• Record Type: Journal Article
• Authors: Song, Jinju; Gim, Jihyeon; Kim, Sungjin; Kang, Jungwon; Mathew, Vinod; Ahn, Docheon; Kim, Jaekook
• Is Part Of: Chemistry, an Asian journal. Volume 9:Issue 6(2014:Jun.)
• Page Start: 1550
• Page End: 1556
• Publication Date: 2014-04-01
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1002/asia.201301510
• Languages: English
• ISSNs: 1861-4728

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>A nonstoichiometric sodium manganese oxide (Na_{<italic>x</italic>}MnO_{2+<italic>δ</italic>}) cathode useful for sodium batteries was synthesized by an ambient‐temperature strategy that involved facile reduction of aqueous sodium permanganate in sodium iodide and subsequent heat treatment at 600 °C. Combined powder X‐ray diffraction and synchrotron X‐ray diffraction analyses confirmed the annealed sample to belong to a Na_{<italic>x</italic>}MnO₂ phase with a <italic>P</italic>2‐hexagonal structure. The ICP‐AES results confirmed the stoichiometry of the sample to be Na_0.53MnO_{2+<italic>δ</italic>}. Electron microscopy studies revealed the particle size of the electrode to be in the range of a few hundred nanometers. The Na_0.53MnO_{2+<italic>δ</italic>} cathode delivered an average discharge capacity of 170 mA h g⁻¹ with a stable plateau at 2.1 V for the initial 25 cycles versus sodium. Ex situ XANES studies confirmed the reversible intercalation of sodium into Na_0.53MnO_{2+<italic>δ</italic>} and suggested the accommodation of over‐stoichiometric Mn⁴⁺ ions to contribute towards the performance of the electrode.</p> </abstract>