无机聚合物正极材料聚三硫代磷氮烯的制备与表征

合成了无机化合物聚三硫代磷氮烯NPS3]n,借助红外光谱与元素分析测试确定了聚合物的重复单元结构;并通过比表面积分析、粒度测试和扫描电子显微镜观察了无机聚合物材料的微观形貌;热重分析测试表明材料在300℃以下能够稳定使用;循环伏安实验发现,作为锂二次电池正极材料使用,聚三硫代磷氮烯的电化学还原反应在2.25 V(versus Li/Li+)发生,其可逆的电化学氧化反应在2.51 V(versus Li/Li+)进行;充放电测试显示这种无机材料具有745.2 mAh.g-1的首次放电容量,与理论值(759.0 mAh.g-1)十分接近,经过60次充放电循环后放电容量保持在708.8 mAh.g-1,容量保持率95.1%,循环性能优秀.

THE PREPARATION AND CHARACTERIZATION OF POLY(PHOSPHAZENE TRIFULFIDE) AS AN INORGANIC POLYMER CATHODE MATERIAL

A novel inorganic compound poly(phosphazene trisulfide) was synthesized.The polymer's molecular structure was determined by element content analysis and IR spectrum.It's microscopic morphology was characterized by specific surface area,granularity analysis and scanning electron microscopy(SEM).The effective working temperature is under 300℃,which is ascertained by thermogravimetric analysis.In cycle volt-ampere experiments,the reversible electrochemical redox reaction occurred at 2.25 V(versus Li/Li~+ for the reduction process) and 2.51 V(versus Li/Li~+ for the oxidation process).The first discharge capacity of the polymer is 745.2 mAh·g~(-1),and the polymer can hold the discharge capacity at 708.8 mAh·g~(-1) after 60 repeated cycles.Taking into consideration the incombustibility,the conductivity,high capacity density and excellent cycle ability of this polymer,poly(phosphazene trisulfide) is a promising cathode material and has a huge application potential.