蒙脱石对介孔炭复合硫正极性能的影响

Effect of montmorillonite on the performance of mesoporous carbon/sulfur composite electrode

为了减少电解液中的活性多硫离子扩散,抑制"飞梭效应",在介孔炭(MC)复合硫(MC/S)正极中添加蒙脱石,并进行充放电测试、循环伏安和交流阻抗谱分析。添加蒙脱石的电极第2次循环的放电容量保持率大于未添加蒙脱石的电极,加入蒙脱石有利于活性物质在介孔炭电极表面的均匀分布,但会增加电极阻抗。蒙脱石添加量为10%的电极性能较好,以10 mA/g的电流在1.5～3.0 V充放电,首次放电比容量为1 387.0 mAh/g,第2次循环的放电容量保持率为90.5%。

In order to prevent diffusion of polystdfides in the electrolyte and decrease the ＂shuttle effect＂, montmorillonite was added into the mesoporous carbon/sulfur composite （ M C/S） electrode. Charge-discharge test, cyclic voltammetry and electrochemi- cal impedance spectroscopy analyses were taken. The retention rate of 2nd discharge capacity of electrodes with montmorillonite was much higher than that without montmofillonite. Adding montmorillonite benefited the uniform distribution of active substances on the surface of mesoporous carbon, but increased the impedance of electrodes. Electrode with 10% amount of montmorillonite showed better performance. When charged-discharged in 1.5 - 3.0 V with the current of 10 mA/g,its initial discharge specific ca- pacity was 1 387.0 mAh/g and the retention rate of 2nd discharge capacity was 90.5%.