新型正极材料三硫代环磷氮烯无机聚合物的合成

Abstract

采用缩合聚合方法合成了新型三硫代环磷氮烯无机聚合物[(NPS3)3]n,利用红外光谱测试与元素含量分析技术证明了[(NPS3)3]n的分子结构与组成,并对聚合物材料的粒度、比表面积及微观形貌进行了考察.TG/DTA实验证明材料在200℃以下具有良好的热稳定性.循环伏安测试表明[(NPS3)3]n正极材料在锂电池体系具有2.15 V的电化学还原电位和2.45 V的电化学氧化电位,经充放电循环实验观察,材料的首次放电容量达到749.0 mAh·g-1,与理论容量(759.0 mAh·g-1)十分接近;经过50次充放电循环后,放电容量保持在674.8 mAh·g,具有很高的使用容量和优秀的循环性能.

A new inorganic polymer cyclic phosphazene trisulfide material was synthesized and characterized by IR, elemental analysis, particle size, specific-surface area measurement, SEM, TG experiment and cyclic volt-ampaere analysis techniques. The results show that the material has a good thermal stability under 200 degrees C, a reduction current peak at 2.15 V and an oxidation current peak at 2.45 V when used as cathode material in lithium secondary battery. During repeated charge-discharge cycles, [(NPS3)(3)](n) revealed a first discharge capacity of 749.0 mAh (.) g(-1) that is very close to the theoretical one (759.0 mAh (.) g(-1)), it also retained the discharge capacity of 674.8 mAh (.) g(-1) after 50 cycles.