羟基化多壁碳纳米管掺杂抑制锂硫电池的穿梭效应

为了抑制锂硫电池的“穿梭效应”，改善锂硫电池的电化学性能。正极片掺杂羟基化多壁碳纳米管（MWCNTs—OH），利用亲水性羟基官能团对多硫化物的吸附作用，阻止多硫化物的扩散，增加有效物质的利用率，抑制穿梭效应的产生，提高锂硫电池的容量和循环性能。利用TEM、SEM和EDS等进行结构和性能表征。电化学测试结果表明，掺杂MWCNTs—OH的锂硫电池，放电容量明显提高。在0.1 C倍率，首次放电比容量达到1 281 mAh/g，首次库伦效率接近96.7%，循环10次后比容量还保持在882 mAh/g。在0.2 C、0.5 C和1 C倍率下充放电时，电池首次放电比容量分别达到794.2 mAh/g、712.2 mAh/g和557.3 mAh/g，显示出极佳的倍率性。 

Inhibiting shuttle effect of lithium sulfur batteries by introducing hydroxylated multi-walled carbon nanotube

The present work aimed to restrain shuttle effect of lithium-sulfur (Li-S) batteries and improve the cycle performance. Hydroxylated multi-walled carbon nanotube (MWCNTs-OH) was used in the positive electrode to absorb polysulfides for cheking the shuttle effect. The diffusion of polysulphides was prevented from absorbing of hydroxyl groups to them. The utilization of active materials was enhanced.The capacity and cycle performance of lithium-sulfur batteries were greatly improved. The morphology and structure of electrodes were observed by TEM, SEM and EDS. The electrochemical test results show that the initial discharge specific capacity of Li-S batteries with the MWCNTs-OH reaches to 1 281 mAh/g and the coulomb efficiency reaches around 96.7%. The discharge capacity remains 882 mAh/g after 10 cycles. The batteries maintained a discharge specific capacity of 794.2 mAh/g, 712.2 mAh/g and 557.3 mAh/g at the current rate of 0.2 C, 0.5 C and 1 C respectively, showing excellent magnification.