Iron Telluride-Decorated Reduced Graphene Oxide Hybrid Microspheres as Anode Materials with Improved Na-Ion Storage Properties

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• 作者：Jung Sang Cho ; Seung Yeon Lee ; Jung-Kul Lee ; Yun Chan Kang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：August 24, 2016
• 年：2016
• 卷：8
• 期：33
• 页码：21343-21349
• 全文大小：579K
• 年卷期：0
• ISSN：1944-8252

文摘

Transition-metal telluride materials are studied as the anode materials for Na-ion batteries (NIBs). The FeTe₂–reduced graphene oxide (rGO) hybrid powders (first target material) are prepared via spray pyrolysis and subsequent tellurization. The H₂Te gas treatment transforms the Fe₃O₄–rGO powders to FeTe₂–rGO hybrid powders with FeTe₂ nanocrystals (various sizes <100 nm) embedded within the rGO. The FeTe₂–rGO hybrid powders contain 5 wt % rGO. The Na-ion storage mechanism for FeTe₂ in NIBs is described by FeTe₂ + 4Na⁺ + 4e^–↔Fe + 2Na₂Te. The FeTe₂–rGO hybrid discharge process forms metallic Fe nanocrystals and Na₂Te by a conversion reaction of FeTe₂ with Na ions. The discharge capacities of the FeTe₂–rGO hybrid powders for the first and 80th cycles are 493 and 293 mA h g^–1, respectively. The discharge capacities of the bare FeTe₂ powders for the first and 80th cycles are 462 and 83 mA h g^–1, respectively. The FeTe₂–rGO hybrid powders have superior Na-ion storage properties compared to bare FeTe₂ powders owing to their high structural stability and electrical conductivity.