中间相炭微球/活性炭复合材料的电化学行为

Electrochemical behavior of a carbonaceous mesophase sphere/activated carbon composite

  • 摘要: 以中间相炭微球(CMS)为核心材料, 沥青为壳层材料前躯体, 采用原位生成法制备了中间相炭微球/活性炭(AC)复合材料。将所制CMS/AC复合材料作为超级电容电池的负极材料,组装了模拟电容器和锂离子半电池。采用扫描电镜和X-射线衍射仪分析了材料的物理结构, 并研究了CMS/AC复合材料的电化学行为进行研究。结果表明:CMS/AC复合负极材料在六氟磷锂/碳酸乙烯酯+碳酸二甲酯(LiPF6/EC+DMC)与四氟硼酸四乙基铵/乙腈(Et4NBF4/AN)电解液中均表现出良好的电化学性能, 其比电容在模拟电容器中达到25.8F/g,在锂离子半电池中能达到306.6mAh/g (0.2C);同时表现出良好的倍率性能和循环性能。

     

    Abstract: Carbonaceous mesophase spheres and medium coal tar pitch with a weight ratio of 3 were mixed in absolute ethanol solution, to which KOH was added to form a slurry. The slurry was heated to 800℃ to carry out KOH activation. The structure of the resulting material was examined by scanning electron microscopy and X-ray diffraction. Electric double layer capacitors and half-cells were fabricated to investigate its electrochemical performance. The material exhibited good performance in both LiPF6/(ethylene carbonate + dimethyl carbonate) and Et4NBF4/acetonitrile electrolytes with a high reversible capacity of 306.6mAh/g (0.2C) in the half-cell and a capacitance of 25.8F/g in the capacitor. The material showed a favorable rate performance and good cycle stability.

     

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