碳纤维布载三维网状聚苯胺在RCl(R=H,Li,Na,K)水溶液中的电容性能对比

Capacitive Performance Comparison of Carbon Fiber Cloth Supported Three-Dimensional Polyaniline Networks in RCl (R = H,Li,Na,K) Aqueous Solution

通过电化学聚合法制备了碳纤维布载三维网状聚苯胺电极,采用扫描电子显微镜、傅里叶红外光谱仪和X射线光电子能谱仪观察了电极形貌,并分析了电极表面特征基团。接着,对比研究了该电极在4种RCl(R=H,Li,Na,K)水溶液中的电容性能。电化学测试表明,在KCl中的电势窗口(1. 8 V)大于在HCl和Li Cl中的电势窗口,且在KCl中的比电容(501 F/g@0. 5 A/g)远远大于Na Cl中的比电容;即使在10 A/g的充放电电流下,电极在KCl溶液中的能量密度仍高于HCl溶液中2. 0 A/g下的能量密度,因此KCl为聚苯胺基电容器最佳的电解质类型。本文通过简单地改变水系溶液中电解质的种类,即可达到拓宽电势窗口、显著提升电化学电容器能量密度的目的,避免了使用有机溶液带来的物理化学稳定性差、污染环境的问题。

Carbon fiber cloth supported three-dimensional polyaniline networks were synthesized by electrochemical polymerization. Scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectrometer were applied to characterize the morphology of the electrode and analyze the characteristic groups on the electrode surface. The capacitive performance of the as-prepared electrode in four RCl(R=H,Li,Na,K) aqueous solutions was systematically compared. The electrochemical tests show that KCl electrolyte gives a wider potential window(1.8 V) than the HCl or LiCl electrolyte, and also exhibits a superior specific capacitance(501 F/g@0.5 A/g) to the NaCl electrolyte. The energy density under the current density of 10 A/g in the KCl electrolyte is even larger than that in the HCl electrolyte under 2.0 A/g. As a result, KCl is the most suitable electrolyte for the polyaniline-based capacitor. The potential window is widened and the energy density of electrochemical capacitor is remarkably improved just simply by altering the electrolyte in the aqueous solution, which avoids the issues of poor physico-chemical stability and severe environment contamination originated from the organic solutions.