Electrospun FeS2@Carbon Fiber Electrode as a High Energy Density Cathode for Rechargeable Lithium Batteries

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• 作者：Yujie Zhu ; Xiulin Fan ; Liumin Suo ; Chao Luo ; Tao Gao ; Chunsheng Wang
• 刊名：ACS Nano
• 出版年：2016
• 出版时间：January 26, 2016
• 年：2016
• 卷：10
• 期：1
• 页码：1529-1538
• 全文大小：684K
• ISSN：1936-086X

文摘

In this study, an FeS₂@carbon fiber electrode is developed with FeS₂ nanoparticles either embedded in or attached to carbon fibers by using an electrospinning method. By applying this binder-free, metal-current-collector-free FeS₂@carbon fiber electrode, both the redox reaction and capacity decay mechanisms for the Li–FeS₂ system are revealed by changing the electrolyte (conventional carbonate electrolyte and a “solvent-in-salt”-type Li–S battery electrolyte) and working voltage ranges (1.0–3.0 V and 1.5–3.0 V vs Li/Li⁺). The FeS₂@carbon fiber electrode shows stable cycling performance in both the conventional carbonate electrolyte and the solvent-in-salt-type Li–S battery electrolyte in the voltage range of 1.5–3.0 V. Electrochemical tests in the solvent-in-salt-type Li–S battery electrolyte indicate that the Li–FeS₂ system becomes a hybrid of the Li–S cell and Li–iron sulfide cell after the initial cycle. Based on the understanding on the capacity decay mechanisms, the cycling stability of the Li–FeS₂ system in the voltage range of 1.0–3.0 V is then significantly enhanced by coating the FeS₂@carbon fiber electrode with a thin layer of Al₂O₃. The Al₂O₃-coated electrode demonstrates excellent cycling performance with high discharge energy densities at both the material level (～1300 Wh/kg-FeS₂) and the electrode level (～1000 Wh/kg-FeS₂ electrode).