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A Sodium Manganese Oxide Cathode by Facile Reduction for Sodium Batteries
Author(s) -
Song Jinju,
Gim Jihyeon,
Kim Sungjin,
Kang Jungwon,
Mathew Vinod,
Ahn Docheon,
Kim Jaekook
Publication year - 2014
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.201301510
Subject(s) - sodium , inorganic chemistry , manganese , stoichiometry , materials science , intercalation (chemistry) , oxide , electrochemistry , cathode , chemistry , electrode , metallurgy , organic chemistry
A nonstoichiometric sodium manganese oxide (Na x MnO 2+ δ ) 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 x MnO 2 phase with a P 2‐hexagonal structure. The ICP‐AES results confirmed the stoichiometry of the sample to be Na 0.53 MnO 2+ δ . Electron microscopy studies revealed the particle size of the electrode to be in the range of a few hundred nanometers. The Na 0.53 MnO 2+ δ 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 0.53 MnO 2+ δ and suggested the accommodation of over‐stoichiometric Mn 4+ ions to contribute towards the performance of the electrode.