本文選題：超級電容器　切入點：Co_3O_4　出處：《中北大學》2017年碩士論文

【摘要】：在諸多的過渡金屬氧化物中,立方尖晶石型Co_3O_4由于其易于制備、環(huán)境友好成本低廉及具有相對較高的比電容等優(yōu)點,被認為是一種很有潛力的超級電容器材料。但是由于Co_3O_4電極材料導電性差(具半導體性質(zhì)),導致其在充放電過程中容量衰減較為明顯,特別是在大倍率充放電下的循環(huán)穩(wěn)定性能較差,因此開發(fā)具有優(yōu)異電化學性能的Co_3O_4先進功能材料具有重要的意義。近年來,直接生長在集流體上的過渡金屬氧化物電極材料,逐漸引起人們的關注,這樣不僅可以避免在電極制備過程中使用導電乙炔黑、粘結(jié)劑等惰性輔助材料,使得活性材料與集流體間直接接觸,并且制作方法簡單、得到的電極材料導電性好。本文利用在泡沫鎳上直接生長Co_3O_4活性材料,對其不同反應條件進行研究,利用XRD,SEM等分別表征了其形貌、晶體結(jié)構(gòu),并測試了材料的電化學性能。主要研究工作如下:(1)利用不同鈷源制備Co_3O_4,分別得到繡球狀,納米立方體狀,餅干狀,及片狀的Co_3O_4顆粒,并對其進行XRD及形貌表征,并進一步研究了Co_3O_4的形成機理。以Co(NO3)2·6H2O做鈷源時,在熱分解過程中將會釋放出NO2氣體,使形成的三維體狀Co_3O_4具有疏松多孔的特點;而以CoCl2·6H2O作為鈷源時,生成的二維片狀Co_3O_4,則不存在這一現(xiàn)象。(2)采用水熱-熱分解法在進行泡沫鎳上負載Co_3O_4電極材料的實驗中,通過控制變量,改變水熱反應時間、反應時鈷離子的濃度及熱分解時煅燒溫度,對所得產(chǎn)物進行結(jié)構(gòu)及形貌的表征,及電化學性能的測試,結(jié)果表明:在水熱反應時長12h,溶液中鈷離子濃度0.04mol/L,煅燒溫度500℃時,所得產(chǎn)物具有良好的電化學性能。在上述最佳實驗條件下在泡沫鎳上進行Co_3O_4納米電極材料的制備,并對其結(jié)構(gòu)形貌進行表征及電化學性能進行測試。結(jié)果表明:長在泡沫鎳基體上的Co_3O_4花狀顆粒,比電容最高可達580.10F/g,且在放電電流密度為4A/g時,循環(huán)1000次后比電容仍能保持最初的95.703%,具有優(yōu)異的循環(huán)穩(wěn)定性。(3)采用溶劑熱-熱分解法制備出單獨Co_3O_4電極材料及Co_3O_4/NiO復合電極材料,并對Co_3O_4與NiO比例為1:1,2:1和水熱反應加熱12h,24h的情況下的電極材料進行制備和電化學性能的研究。結(jié)果表明,單獨Co_3O_4電極材料的電化學性能比Co_3O_4/NiO復合電極材料好。這可能是由于復合材料的顆粒尺寸較大等原因,因此關于如何提高復合材料的性能方面,還需進一步研究。
[Abstract]:Among all the transition metal oxides, cubic spinel Co_3O_4 has the advantages of easy preparation, low cost and relatively high specific capacitance. It is considered to be a potential supercapacitor material. However, due to the poor conductivity of Co_3O_4 electrode materials (semiconductor properties), the capacity attenuation is more obvious during the charge-discharge process. Especially, the cyclic stability is poor at large rate charge / discharge, so it is of great significance to develop advanced functional Co_3O_4 materials with excellent electrochemical properties. In recent years, transition metal oxide electrode materials have grown directly on the collector. In this way, the inert auxiliary materials such as conductive acetylene black, binder and other inert auxiliary materials can be avoided in the preparation of the electrode, which makes the active material contact directly with the collector, and the preparation method is simple. The electrode materials obtained have good electrical conductivity. In this paper, the morphology and crystal structure of Co_3O_4 active materials grown directly on nickel foam were studied under different reaction conditions. The electrochemical properties of the material were tested. The main research work was as follows: 1) CoS3O _ 4 was prepared by using different cobalt sources. The Co_3O_4 particles in the shape of embroidered ball, nano-cube, biscuit and flake were obtained, and their XRD and morphology were characterized. The formation mechanism of Co_3O_4 was further studied. When Co(NO3)2 6H2O was used as cobalt source, NO2 gas would be released in the process of thermal decomposition, which made the three-dimensional bulk Co_3O_4 porous and porous, while CoCl2 6H2O was used as cobalt source. In the experiment of loading Co_3O_4 electrode material on nickel foam by hydrothermal decomposition method, the reaction time of hydrothermal reaction was changed by controlling the variables. The concentration of cobalt ion during reaction and the calcination temperature during thermal decomposition, the structure and morphology of the product were characterized, and the electrochemical properties were tested. The results showed that the concentration of cobalt ion in solution was 0.04 mol / L, the calcination temperature was 500 鈩，

本文編號：1666449