【摘要】：近些年來,超級電容器由于具有諸多優(yōu)勢而逐漸受到社會的關(guān)注,很多人都將其視為一種很具潛力的電化學(xué)儲能器件。在當前的研究中,碳基材料、導(dǎo)電高分子及過渡金屬氧化物的復(fù)合材料因為其資源豐富、價格低廉和環(huán)境友好以及良好的電化學(xué)性能而成為研究熱點。然而,石墨烯材料雖然理論的比表面積很大,但是實際上能夠有效被利用的面積卻很少,這是由于石墨烯容易發(fā)生團聚而導(dǎo)致有效的利用面積減少引起的。而在本課題研究中,我們采用經(jīng)過改性處理的碳納米管與氧化石墨烯復(fù)合,增大其可利用的比表面積,在此基礎(chǔ)上通過一種簡單易控的方法與錳氧化物復(fù)合,并對其復(fù)合材料的電化學(xué)性能進行測試。首先,通過在異丙醇-水二元體系中制備錳氧化物的納米晶并使其沉積在氧化石墨烯的表面,從而制得氧化石墨烯-錳氧復(fù)合材料。通過對復(fù)合材料進行SEM、XRD、拉曼以及XPS等表征分析,分析不同投料比與冷卻速度下樣品的物性特征;然后,對其復(fù)合材料進行性能測試分析,發(fā)現(xiàn)當其投料比為1:9時,材料的性能達到最佳。相對于回流(初始溫度80℃)冷卻至室溫,經(jīng)過冰水(大約5℃)快速激冷后,材料具有更高的電化學(xué)性能。通過恒電流充放電計算得出回流冷卻方式下比電容最大為253.12 F/g,其循環(huán)性能達到88.16%,而冰水快速激冷方式下比電容達到312.87 F/g,循環(huán)性能達到85.12%。在氧化石墨烯-錳氧化物復(fù)合的基礎(chǔ)上,引入表面帶不同電荷的碳納米管,分析不同電負性的碳納米管與氧化石墨烯的結(jié)合對材料性能的影響。通過相同的手段對材料進行物性分析和性能分析,發(fā)現(xiàn)帶負電荷的碳納米管的性能略優(yōu)于帶正電的碳納米管。當碳納米管與氧化石墨烯-錳氧化物的比例為1:1:6時,材料的性能達到最優(yōu),最大可達306.82 F/g,其循環(huán)穩(wěn)定性能可高達76.87%。最后,通過保持氧化石墨烯-錳氧化物的比例不變,改變碳納米管與氧化石墨烯的比例分析不同比例條件下對材料性能的影響,發(fā)現(xiàn)當碳納米管含量的增加時,性能并沒有相應(yīng)的提升,這可能是由于碳納米管在后續(xù)制備過程中出現(xiàn)團聚現(xiàn)象導(dǎo)致比表面積的減少所造成的。
[Abstract]:In recent years, supercapacitors have attracted more and more attention due to their many advantages. Many people regard supercapacitors as a potential electrochemical energy storage device. In the current research, carbon based materials, conductive polymers and transition metal oxide composites have become the focus of research because of their rich resources, low cost, environmental friendliness and good electrochemical performance. However, although the theoretical specific surface area of graphene materials is very large, in fact, the area that can be effectively utilized is very small, which is caused by the reduction of effective utilization area due to the easy agglomeration of graphene. In this study, we use modified carbon nanotubes (CNTs) and graphene oxide to increase the available specific surface area, and on this basis, we use a simple and easily controlled method to compound with manganese oxide. The electrochemical properties of the composites were tested. Firstly, the nanocrystalline of manganese oxide was prepared in isopropanol-water binary system and deposited on the surface of graphene oxide. The physical properties of the composites were analyzed by SEM,XRD, Raman and XPS analysis under different feed ratio and cooling rate. Then, the properties of the composites were tested and analyzed, and it was found that when the feed ratio was 1:9, the properties of the composites were the best. Compared with reflux (initial temperature 80 鈩，

本文編號：2341967