聚酰亚胺在不同电解液体系中的储钠性质

Sodium Storage Properties of Polyimide in Different Electrolytes

共轭羰基化合物以其高理论比容量与多电子参与等优势成为当前最具研究吸引力的有机电极材料之一。本文以苝四甲酸二酐(PTCDA)与尿素进行缩聚反应制备含有共轭多羰基单元的聚酰亚胺(PI),采用傅里叶转换红外线光谱分析仪(Fourier transform infrared spectroscope,FT-IR)、X射线衍射(X-ray diffraction,XRD)和扫描电子显微镜(Scanning electron microscope,SEM)等测试方法对其进行了表征,并将所制备的材料用作钠离子电池正极材料,研究了其在NaClO4/EC∶DMC和NaClO4/EC∶PC两种电解液体系中的嵌钠性质。结果表明:在NaClO4/EC∶PC中,PI的初始比容量最高,循环稳定性最好;在电流密度为0.3C(1C=118mA·g-1)时,循环100次后放电容量可达124mAh·g-1。优异的电化学性质主要归因于NaClO4/EC∶PC高的离子电导率,因而PI在其中具有较好的动力学性能,进而表现出更优的电化学性能。

The conjugated carbonyl compounds have emerged as an interesting option as organic electrode materials for rechargeable batteries due to their unique advantages including high theoretical capacity and multi-electron reactions.A conjugated carbonyl-based polyimide（PI）is synthesized through the imidization reaction of perylene-3,4,9,10-tetracarboxylic dianhydride（PTCDA）and urea.Fourier transform infrared spectroscope（FT-IR）,X-ray diffraction（XRD）,and scanning electron microscope（SEM）are performed to characterize their morphologies and structures.The electrochemical performance of PI is studied in two different electrolytes,NaClO4/EC∶DMC and NaClO4/EC∶PC,respectively.As a cathode material for sodium-ion batteries,PI exhibits a better specific capacity and cyclic stability in NaClO4/EC∶PC.At a current density of 0.3C（1C=118 mA·g-1）,the stable discharge capacity of124mAh·g-1after 100charging/discharging cycles can be achieved.The improved electrochemical performance of the PI electrode is attributed to the high ionic conductivity of NaClO4/EC∶PC,thus PI has the better dynamic performance in NaClO4/EC∶PC.