Metal鈥揝ulfur Battery Cathodes Based on PAN鈥揝ulfur Composites

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• 作者：Shuya Wei ; Lin Ma ; Kenville E. Hendrickson ; Zhengyuan Tu ; Lynden A. Archer
• 刊名：Journal of the American Chemical Society
• 出版年：2015
• 出版时间：September 23, 2015
• 年：2015
• 卷：137
• 期：37
• 页码：12143-12152
• 全文大小：634K
• ISSN：1520-5126

文摘

Sulfur/polyacrylonitrile composites provide a promising route toward cathode materials that overcome multiple, stubborn technical barriers to high-energy, rechargeable lithium鈥搒ulfur (Li鈥揝) cells. Using a facile thermal synthesis procedure in which sulfur and polyacrylonitrile (PAN) are the only reactants, we create a family of sulfur/PAN (SPAN) nanocomposites in which sulfur is maintained as S₃/S₂ during all stages of the redox process. By entrapping these smaller molecular sulfur species in the cathode through covalent bonding to and physical confinement in a conductive host, these materials are shown to completely eliminate polysulfide dissolution and shuttling between lithium anode and sulfur cathode. We also show that, in the absence of any of the usual salt additives required to stabilize the anode in traditional Li鈥揝 cells, Li鈥揝PAN cells cycle trouble free and at high Coulombic efficiencies in simple carbonate electrolytes. Electrochemical and spectroscopic analysis of the SPAN cathodes at various stages of charge and discharge further show a full and reversible reduction and oxidation between elemental sulfur and Li-ions in the electrolyte to produce Li₂S as the only discharge product over hundreds of cycles of charge and discharge at fixed current densities.