水热法合成聚酰亚胺及其储镁性能研究

Hydrothermal Synthesis of Polyimide and Its Magnesium-ion Storage Properties

以1,4,5,8-萘四甲酸酐和对苯二胺为原料,使用水热法在200℃下反应5 h,制备了聚酰亚胺(PI);采用红外光谱法(FTIR)和X射线衍射法(XRD)对其结构进行了表征;同时,组装了以PI为负极、硫酸镁水溶液为电解液、活性炭为正极的电池体系,并测定了PI的储镁性能,充电时,镁离子与负极PI发生还原反应,硫酸根离子嵌入到正极活性炭颗粒中;放电过程相反。恒电流充放电测试表明,在50 mA/g的充放电电流下,PI在首次循环中的充电比容量为107.6 mAh/g,放电比容量为94.6 mAh/g,效率为87.91%;100次循环后,放电比容量降为66.2 mAh/g,库伦效率升高到97.65%。最后,采用循环伏安法CV、EIS对PI电化学性能进行测试,证明PI具有良好的储镁性能。

olyimide(PI)was prepared from 1,4,5,8-naphthalene tetramethylanhydride and p-phenylenediamine as raw materials by hydrothermal reaction at 200℃for five hours.The structure of PI was characterized by infrared spectroscopy(FTIR)and X-ray diffraction(XRD).At the same time,a battery system with PI as the negative electrode,magnesium sulfate solution as the electrolyte and activated carbon as the positive electrode was assembled to determine the magnesium storage performance of PI.During charging,magnesium ion and negative PI are reduced,and sulfate ion is embedded in positive activated carbon particles;the discharge process is reversed.Via constant current charge and discharge tests(50 mA/g),in the first cycle,the charge specific capacity of PI magnesium storage is 107.6 mAh/g,the discharge specific capacity is 94.6 mAh/g,and the efficiency is 87.91%.After 100 cycles,the discharge specific capacity decreased to 66.2 mAh/g and the Coulombic efficiency increased to 97.65%.Finally,the electrochemical performance of PI was tested by cyclic voltammetry(CV)and EIS methods,which proved that PI had decent magnesium storage performance.