硫/水热碳球复合材料的制备及对锂硫电池倍率性能的影响 |
Sulfur-Hydrothermal Carbon Composites for Cathode in High-Rate Lithium-Sulfur Batteries |
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摘要: 在锂硫电池正极材料的研究中,碳材料可以有效改善电池倍率及循环性能。为了提高锂硫电池的高倍率放电性能,通过水热合成的方法,制备了由非均匀粒径碳球组成的碳材料。与硫热合成后,硫均匀分布在碳材料表面及周围,复合材料含硫量为52wt%。0.2C放电电流下,首次放电比容量为1 174 mAh·g-1,100次循环后放电比容量为788 mAh·g-1。在4C的放电电流下,放电比容量稳定维持在600 mAh·g-1,循环过程中,库伦效率高于90%。该碳材料有良好的导电网络,且制备方便,成本低廉,对于穿梭效应和放电过程中的膨胀效应有一定的抑制作用,是一种优秀的正极材料。 |
关键词: 锂硫电池 水热法 硫碳复合材料 高倍率 |
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Abstract: Sulfur-carbon composites as the cathode of Lithium-Sulfur batteries have shown excellent electrochemical performance for high power devices. To enhance rate performance of sulfur cathode for Li-S batteries, a carbon material consisted of non-uniform carbon spheres has been prepared by hydrothermal method. Sulfur disperses evenly on the surface of the carbon spheres via a melt-diffusion method. The as-prepared composite with a sulfur content of 52wt% delivers an initial discharge capacity of 1 174 mAh·g-1 and a reversible discharge capacity of 788 mAh·g-1 after 100 cycles at 0.2C. At a higher rate of 4C, the capacity stabilizes at around 600 mAh·g-1. During cycling, the coulombic efficiency is maintained above 90%. The results show that the carbon-sulfur composites with chain conductive network represents a promising cathode material for rechargeable lithium batteries because of the effective improvement of the electronic conductivity, the restraint of the volume expansion and the reduction of the shuttle effect. |
Keywords: lithium-sulfur batteries hydrothermal sulfur/carbon composite high-rate |
投稿时间:2014-09-25 修订日期:2015-01-01 |
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李严冰,段晓波,韩亚苗,朱丁,黄利武,陈云贵.硫/水热碳球复合材料的制备及对锂硫电池倍率性能的影响[J].无机化学学报,2015,31(4):641-648. |
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