三聚磷腈复合硫正极材料性能的改进研究

采用加热法,将三聚磷腈复合硫(TPS)正极材料与介孔炭复合,以期望改善电极性能.扫描电子显微镜显示TPS具有与硫不同的表面形貌,接触角测定表明水滴与TPS表面的接触角为35°,而硫表面的接触角为115.,XRD和IR测定证明TPS结构特征为表面经过磷腈基团修饰的硫.复合介孔炭后,TPS电极性能改善,在10mA/g的充放电电流下,其首次放电容量为767mAh/g,第二周容量保持率为84.8％,30次循环后容量为303.8mAh/g.

Improvement of the electrochemical properties of triphosphazene-sulfur composite as cathode materials for lithium-sulfur batteries

Mixture of triphosphazene-sulfur composite(TPS) and mesoporous carbon were prepared by heat treatment with the aim to improve TPS’ electrochemical properties.Results of scanning electron microscope test show that the morphology of TPS’ surface was different from that of elemental sulfur;data of contact angle measurement was that the contact angle of water droplet with TPS’ surface was 35°,while that of elemental sulfur’s surface was 115°;results of XRD and IR test prove that structural characteristic of TPS was the same as sulfur,with its surface decorated by phosphazene groups.When TPS mixed with mesoporous carbon,it showed improved electrochemical properties.At the constant current of 10mA/g,its initial discharge capacity was 767mAh/g,the second cycle of capacity retention rate was 84.8%,its discharge capacity remained at 303.8mAh/g after 30 cycles.