碳纳米管/活性炭复合电极的电容特性

Characteristics of carbon nano tubes/active carbon material as polarizable combination electrode for electric double-layer capacitor

为改进活性炭电极组成的电双层电容器 (EDLC)的性能 ,采用碳纳米管 (CNT) /活性炭 (AC)复合材料制备可极化电极。考察了CNT对电容器性能的影响 ,用DC 5电池试验仪测试了其充放电性能、循环容量稳定性及自放电现象。结果表明 ,碳纳米管能有效地降低可极化电极的内阻 ,增强充放电循环稳定性 ,并降低EDLC的自放电速率。当复合电极中CNT含量为 5 % (质量百分数 )时 ,充电截止电压为 3V的条件下 ,CNT/AC复合电极的放电容量达 43F/g ,而AC电极仅 3 3F/g ,复合电极组成的EDLC的自放电速率下降约 5 0 %。

The polarizable recombination electrode was prepared by using the carbon nano tubes (CNT)/active carbon (AC) recombination material in order to improve the performance of electric double layer capacitor (EDLC) with active carbon as electrode material. The charge/discharge performance, the stability of cyclic capacity and the self discharge of CNT were tested with DC 5 battery tester in order to evaluate the effect of CNT on the performance of EDLC. The results show that the internal resistance of polarizable electrode and the self discharge rate of EDLC are decreased obviously while the cyclic stability is improved by CNT. When the CNT content in the recombination electrode is 5% (mass percentage) and the cut off voltage for charging is 3 V, the specific discharge capacitance of CNT/AC recombinaton electrode is up to 43 F·g -1 , whereas that of AC electrode is only 33 F·g -1 . The self discharge rate of EDLC with recombination electrode is reduced by about 50%.