Cobalt‐Doped FeS2 Nanospheres with Complete Solid Solubility as a High‐Performance Anode Material for Sodium‐Ion Batteries |
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| Authors: | Dr Kai Zhang Mihui Park Limin Zhou Gi‐Hyeok Lee Jeongyim Shin Dr Zhe Hu Dr Shu‐Lei Chou Prof Jun Chen Prof Yong‐Mook Kang |
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| Institution: | 1. Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul, Republic of Korea;2. Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Collaborative Innovation Center of Chemical Science and Engineering, College of Chemistry, Nankai University, Tianjin, China;3. Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, New South Wales, Australia |
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| Abstract: | Considering that the high capacity, long‐term cycle life, and high‐rate capability of anode materials for sodium‐ion batteries (SIBs) is a bottleneck currently, a series of Co‐doped FeS2 solid solutions with different Co contents were prepared by a facile solvothermal method, and for the first time their Na‐storage properties were investigated. The optimized Co0.5Fe0.5S2 (Fe0.5) has discharge capacities of 0.220 Ah g?1 after 5000 cycles at 2 A g?1 and 0.172 Ah g?1 even at 20 A g?1 with compatible ether‐based electrolyte in a voltage window of 0.8–2.9 V. The Fe0.5 sample transforms to layered NaxCo0.5Fe0.5S2 by initial activation, and the layered structure is maintained during following cycles. The redox reactions of NaxCo0.5Fe0.5S2 are dominated by pseudocapacitive behavior, leading to fast Na+ insertion/extraction and durable cycle life. A Na3V2(PO4)3/Fe0.5 full cell was assembled, delivering an initial capacity of 0.340 Ah g?1. |
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| Keywords: | anode materials cobalt-doped iron disulfides sodium-ion batteries solid solutions |
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