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A Sodium Manganese Oxide Cathode by Facile Reduction for Sodium Batteries |
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| Authors: | Jinju Song Jihyeon Gim Sungjin Kim Jungwon Kang Dr Vinod Mathew Dr Docheon Ahn Prof Jaekook Kim |
| Affiliation: | 1. Department of Materials Science and Engineering, Chonnam National University, 300 Yongbong dong, Buk‐gu, Gwangju 500‐757 (South Korea), Fax: (+82)?62‐530‐1699;2. Beamline Research Division, Pohang Accelerator Laboratory, Pohang 790‐784 (South Korea) |
| Abstract: | A nonstoichiometric sodium manganese oxide (NaxMnO2+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 NaxMnO2 phase with a P2‐hexagonal structure. The ICP‐AES results confirmed the stoichiometry of the sample to be Na0.53MnO2+δ. Electron microscopy studies revealed the particle size of the electrode to be in the range of a few hundred nanometers. The Na0.53MnO2+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 Na0.53MnO2+δ and suggested the accommodation of over‐stoichiometric Mn4+ ions to contribute towards the performance of the electrode. |
| Keywords: | electrochemistry electrodes energy conversion intercalation sodium batteries |
