本文關鍵詞： 雙電層電容器 活性炭 碳納米管 活化劑　出處：《中北大學》2017年碩士論文　論文類型：學位論文

【摘要】：雙電層電容器因其具有高功率密度、快的充放電速率、長循環(huán)壽命等特點,受到許多人的關注。在電極/電解質(zhì)界面,雙電層電容器物理存儲能量是基于電化學雙電層機制。因此,高比表面積和短離子傳輸路徑是碳基電極材料的基本要求。多孔管狀碳材料同時具備1D納米結(jié)構和多孔結(jié)構的優(yōu)點,不僅可以提供高比表面積,還可以提供快速離子通路和高電解質(zhì)-電極接觸面積,使得電解質(zhì)離子的傳輸更快和電極的利用率更高。本文中以FeCl_3為催化劑,三聚氰胺為碳源,通過熱解制備不同微觀結(jié)構的N摻雜碳納米管(CNTs)。通過三聚氰胺和FeCl_3的摩爾比和煅燒溫度來調(diào)控N摻雜CNTs的微觀結(jié)構。當三聚氰胺和FeCl_3的摩爾比為4,碳化溫度為700℃時,形成具有竹節(jié)狀結(jié)構的CNTs。樣品的BET表面積和電容隨著三聚氰胺和FeCl_3的摩爾比的增加而增加,并且最大BET表面積和電容分別為294 m~2/g和67 F/g。但是,低電容對于雙電層電容器的電極材料是不夠的。為了進一步提高CNTs的電容性能,我們引入造孔劑ZnCl_2,來增加CNTs的比表面積。通過一步法合成高氣孔率的N摻雜CNTs/Fe_3C。原位形成的Fe_3C納米棒嵌入到CNTs的內(nèi)部結(jié)構�？捉Y(jié)構分析表明,N摻雜的CNTs/Fe_3C擁有大的比表面積高達1206.23 m~2/g。在電流密度為0.1 A/g時,N摻雜的CNTs/Fe_3C電極顯示出181 F/g的高比電容,以及優(yōu)異的電容率和循環(huán)穩(wěn)定性。為了降低制備成本,利用廢棄的生物質(zhì)原料竹筷子作為碳源。通過水熱法除去竹筷子中的木質(zhì)素,來獲得纖維素纖維,然后用KOH作為活化劑來制備多孔碳微管/薄片復合材料。所制備的樣品具有高達2337 m~2/g的比表面積。在6M KOH溶液中,當電流密度0.1 A/g時,表現(xiàn)出212 F/g的高比電容。在電流密度為1 A/g時,經(jīng)過1000次循環(huán)后電容保持率為96%。結(jié)果表明,竹筷子可以作為儲能裝置的原材料。
[Abstract]:Because of its high power density, fast charge and discharge rate and long cycle life, double layer capacitors have attracted much attention. The physical storage of energy in double layer capacitors is based on the electrochemical double layer mechanism. High specific surface area and short ion transport path are the basic requirements of carbon based electrode materials. Porous tubular carbon materials have the advantages of both 1D nanostructure and porous structure, which can not only provide high specific surface area. It can also provide fast ion path and high electrolyte-electrode contact area, which can make electrolyte ion transport faster and electrode utilization higher. In this paper, FeCl_3 is used as catalyst, melamine as carbon source, melamine as carbon source, melamine as carbon source, and melamine as carbon source. N-doped carbon nanotubes with different microstructure were prepared by pyrolysis. The microstructure of N-doped CNTs was controlled by the molar ratio of melamine and FeCl_3 and the calcination temperature. When the molar ratio of melamine to FeCl_3 was 4, the carbonization temperature was 700 鈩，

本文編號：1552766