聚3, 4-二氧乙基噻吩奈米複合材料於超級電容之應用

No Thumbnail Available

Date

2010

Journal Title

Journal ISSN

Volume Title

Publisher

Abstract

聚3, 4-二氧乙基噻吩(PEDOT)擁有相對於其他導電高分子較大之可逆氧化還原電位,可擴大超級電容之電位範圍,提升能量與功率密度,並與其他陽極材料組合非對稱式超級電容器,改善對稱式導電高分子電容器之電位範圍侷限。 本研究主要以電化學聚合法,首次成功合成直接成長於碳布基材之PEDOT奈米線。實驗條件為先以循環伏安法,掃描速率為10 mV/s掃描5圈,再加予1 mA之定電流成長5分鐘,可得直徑約60 nm之PEDOT奈米線。相對於PEDOT薄膜,PEDOT奈米線具有較高表面積並縮短離子擴散距離,以1 M硫酸為電解質,比電容量可達321.1 Fg-1。 另使用直接成長於碳布之奈米碳管做為基材,以電化學循環伏安法(掃描速率為100 mV/s,掃描20圈),將PEDOT包覆於奈米碳管,形成直徑為167.2 nm之PEDOT-CNTs複合材料。利用碳管之高比表面積、導電性與低內電阻等特性,提升功率與功率密度。以1 M硫酸鈉為電解質,所得之能量密度可達138.3 Whkg-1;功率密度可達31.5 kWkg-1,在硫酸水溶液下可得比電容量為486.5 Fg-1。 最後將PEDOT與適合做為陽極材料之聚苯胺(PANI)、氧化錳(MnO2)組合成非對稱式電化學電容器,其電位範圍可分別擴大至1.4 V與2.0 V,改善電位範圍狹隘之缺點。
Poly(3,4-ethylenedioxythiophene)(PEDOT) has the larger reversible oxidation-reduction potential than other conducting polymers. According to this advantage, the potential window, specific energy and specific power of supercapacitor could be increase. Combination with PEDOT and anode materials as asymmetric supercapacitor could get wider cell voltage then symmetric conducting polymer supercapacitor. We had successfully synthesized the direct-grown PEDOT nanowires on carbon cloth by electrochemical polymerization. The 2 cycles of cyclic voltammogram at scan rate 10 mV/s, and then used galvanostatic to growth 5 minutes at 1 mA were operated to fabricated PEDOT nanowires. From SEM, the diameter of PEDOT nanowires was around 60 nm. Compare with PEDOT film, PEDOT nanowires exhibited high surface area and short diffusion distance. The specific capacitance of PEDOT nanowires electrode were 321.1 Fg-1 in 1 M H2SO4. Because of the high surface area, good electrical properties and low internal resistance, the direct-grown carbon nanotubes on carbon cloth was utilized as substrate to raise the power density and energy density. Under the condition of cyclic voltammogram scan (100 mV/s, 20 cycles), PEDOT can be uniformly coated on carbon nanotubes to form PEDOT-CNTs/CC core/shell nanocomposite. From SEM, the diameter of PEDOT-CNTs was 167.2 nm. Furthermore, the specific power and energy of the composite electrode could be increase to 31.5 kWkg-1 and 138.3 Whkg-1 in neutral electrolyte, and its specific capacitance was 486.5 Fg-1 in acidic electrolyte. Finally, we combine PEDOT with anode materials (PANI and MnO2) as asymmetric supercapacitor. The cell voltage could be extended to 1.4 V and 2.0 V.

Description

Keywords

聚3, 4-二氧乙基噻吩, 超級電容, Poly(3, 4-ethylenedioxythiophene), PEDOT, Supercapacitor

Citation

Collections