关键词: 超级电容器, HKUST-1, 多孔, 聚苯胺, 单极脉冲法

Abstract:

Excellent electrode plays vital important role in the performance of supercapacitors. Polyaniline (PANI) with good conductivity is often used to prepare electrode. However, its available surface is limited and results in a poor supercapacitance in many cases. It is desirable to fabricate an electrode containing electroactive PANI with high surface area deriving from its porous structure. Here, the metal-organic framework (MOF) material with high surface area was selected as a hard template for synthesizing porous PANI. Microporous PANI composite electrodes (Micro-PANI/CC) were fabricated by depositing aniline on to carbon cloth (CC) pre-coated with MOF material of HKUST-1 using a unipolar pulse electro-polymerization method. At the same time, the PANI electrodes (PANI/CC) were also synthesized on blank carbon cloth for further comparatively studying their supercapacitor performances. Their microstructure and morphology were characterized by using XRD and SEM. Results indicate that the micro-PANI/CC electrode was composed of aggregated nanosized PANI spheres with pore structure. The cyclic voltammetry, constant current charge and discharge, impedance and stability tests were performed to evaluate the supercapacitor properties in 0.5 mol·L^-1 sulfuric acid electrolyte. Specific capacitances of micro-PANI/CC and PANI/CC electrodes were 895.6 F·g^-1 and 547.6 F·g^-1  at scan rate of 2 mV·s^-1 , respectively. At the same given conditions, the specific capacitance of micro-PANI/CC electrode was always 1.64 times higher than that of PANI/CC electrode. Meanwhile, the micro-PANI/CC electrode exhibited better rate capability, lower resistance and better stability of charge and discharge than PANI/CC. all the results imply that the microporous PANI templated from HKUST-1 could be a good candidate for the electrode of supercapacitors.

Key words: supercapacitor, HKUST-1, porous, polyaniline, unipolar pulse electro-polymerization method