常壓介電質放電噴射電漿改質聚苯胺-石墨烯-殼聚醣軟性超級電容及紙基超級電容製程開發

Abstract

此研究主要是使用碳纖維布作為軟性超級電容的電極，使用氮氣電弧式常壓噴射電漿在基板溫度520℃將碳纖維布表面處理30秒後，網印塗覆上還原氧化石墨烯-聚苯胺-殼聚醣的奈米複合材料，再使用氬氣介電質放電噴射電漿，在不同處理次數與基板溫度40℃下，對表面材料進行改質，最後均勻塗覆上凝膠態硫酸電解液，製作成一組超級電容。另外，亦有研究以發泡鎳與纖維素紙作為基材之超級電容。經由掃描式電子顯微鏡 (SEM)，可以觀察到還原氧化石墨烯、聚苯胺、殼聚醣的奈米複合材料皆均勻分布在碳纖維布上，而由X-射線繞射儀 (XRD)與拉曼光譜儀 (Raman spectroscopy)觀測到在氬氣介電質放電噴射電漿處理後，材料本身之結構皆沒有明顯的改變。由X-射線光電子能譜儀 (XPS)分析處理前後材料表面的化學組成，利用水接觸角儀 (WCA)測量後，可以發現到在氬氣介電質放電噴射電漿處理後，材料表面之親水性鍵結增加，使得親水性上升，可與凝膠態硫酸電解液有更好的接合，進而提升超級電容之容量。另外，亦有探討電漿處理與熱效應對於碳纖維布之親水性影響。在恆電流充電放電測量法 (Galvanostatic Charge-Discharge Test)與循環伏安法（Cyclic Voltammetry Test）下，可以得到在經過氬氣介電質放電噴射電漿處理後，超級電容具有較大之電雙層電容及法拉第電容，電容值皆提高了150 ~ 300%左右，而在機械式彎曲測試與長時間充放電的實驗下，軟性超級電容經過五百次曲率半徑5 mm的機械彎曲與1萬次充放電後，電容值沒有明顯的降低，顯示出軟性超級電容具有良好的機械穩定性和長時間充放電穩定性。經由此研究的結果顯示，在沒有給予樣品加熱處理下，單純以低溫(~40°C)氬氣介電質放電噴射電漿的高反應性離子，便可以改變碳纖維布上還原氧化石墨烯-聚苯胺-殼聚醣複合材料的性質，使軟性超級電容之性能有進一步的提升。

We used carbon fiber cloth as the electrodes of the flexible supercapacitors. The carbon cloth was treated by nitrogen arc atmospheric-pressure plasma jet (APPJ) at a substrate temperature of 520℃ for 30 s. Following which reduced graphene oxide (rGO)-polyaniline (PANI)-chitosan (CS) pastes was screen-printed on APPJ-treated carbon cloth. Ar dielectric barrier discharge jet (DBDjet) was used to modify the material at a substrate temperature of ~40° C with zero, one, and two scans. Through the scanning electron microscopy, it can be observed that the nanocomposite materials of rGO-PANI-CS are uniformly distributed on the carbon cloth. The structure of the rGO-PANI-CS did not change significantly after the Ar DBDjet treatment. Improved hydrophilicity after DBDjet treatment increased capacity of the supercapacitor, as evidenced by X-ray photoelectron spectroscopy and water contact angle measurement. Galvanostatic charging-discharging (GCD) and cyclic voltammetry (CV) results indicate that Ar DBDjet treatment improves the capacitance by 150 ~ 300%. The flexible supercapacitor shows good stability under the mechanical bending test and long-term charging and discharging experiments. Our results show that without substantial heating, only reactive plasma species of Ar DBDjet can substantially alter the properties of rGO-PANI-CS nanocomposites on carbon cloth to improve the performance of supercapacitors