Cobalt-Doped FeS₂ Nanospheres with Complete Solid Solubility as a High-Performance Anode Material for Sodium-Ion Batteries

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• 作者：Dr. Kai Zhang ; Mihui Park ; Limin Zhou ; Gi-Hyeok Lee ; Jeongyim Shin ; Dr. Zhe Hu ; Dr. Shu-Lei Chou ; Prof. Jun Chen and Prof. Yong-Mook Kang
• 刊名：Angewandte Chemie International Edition
• 出版年：2016
• 出版时间：October 4, 2016
• 年：2016
• 卷：55
• 期：41
• 页码：12822-12826
• 全文大小：4092K
• ISSN：1521-3773

文摘

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 Co_0.5Fe_0.5S₂ (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 Na_xCo_0.5Fe_0.5S₂ by initial activation, and the layered structure is maintained during following cycles. The redox reactions of Na_xCo_0.5Fe_0.5S₂ 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.