活性炭纤维毡电极的电容脱盐性能研究

SELF-SUSTAINED ACTIVATED CARBON FIBER WEB ELECTRODE FOR SUPERCAPACITIVE DESALINATION

采用活性炭纤维毡作为自支撑电极材料,组装成电容器进行恒流充放电脱盐测试。循环伏安证明电容器具有理想的双电层电容特性。分别考察了目标电压、充电电流密度对活性炭纤维脱盐性能和电流效率的影响。结果表明,随着电压的升高,脱盐量增加,电流效率先增加后降低;当电流密度过低,脱盐产率太低,而过高的电流密度会导致脱盐量及电流效率的下降。电极表面的pH变化研究证明,随着电压的升高,电极表面碱化严重。

Capacitive deionization technology is based on the electrochemical electric double layer charge and discharge theory to realize desalination and electrode regeneration. In this paper, the activated carbon fiber web, as the self-sustained electrode materials, was assembled into a capacitor. The constant current charge-discharge mode was used in the desalination process. Cyclic voltammetry test demonstrates the ideal double-layer capacitor behavior. Under the constant current charge-discharge condition, the effects of the target voltage and the current density on the desalination performance and current efficiency were investigated, respectively. The conclusion is that the desalination capacity increases with target voltage, while decreases with the changing current density higher than 38 mAJg. The optimal target voltage and current density were obtained by considering the desalination capacity and current efficiency simultaneously, pH change in electrode surface indicate that alkalization became worse with increasing the voltage.