A Sodium Manganese Oxide Cathode by Facile Reduction for Sodium Batteries

作者：Song Jinju^*; Gim Jihyeon; Kim Sungjin; Kang Jungwon; Mathew Vinod; Ahn Docheon; Kim Jaekook

来源：Chemistry-An Asian Journal, 2014, 9(6): 1550-1556.

DOI：10.1002/asia.201301510

• electrochemistry
• electrodes
• energy conversion
• intercalation
• sodium batteries

A nonstoichiometric sodium manganese oxide (NaxMnO2+) 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 degrees C. Combined powder X-ray diffraction and synchrotron X-ray diffraction analyses confirmed the annealed sample to belong to a NaxMnO2 phase with a P2-hexagonal structure. The ICP-AES results confirmed the stoichiometry of the sample to be Na0.53MnO2+. Electron microscopy studies revealed the particle size of the electrode to be in the range of a few hundred nanometers. The Na0.53MnO2+ cathode delivered an average discharge capacity of 170mAhg(-1) with a stable plateau at 2.1V for the initial 25cycles versus sodium. Exsitu XANES studies confirmed the reversible intercalation of sodium into Na0.53MnO2+ and suggested the accommodation of over-stoichiometric Mn4+ ions to contribute towards the performance of the electrode.

• 出版日期2014-6