發(fā)布時間：2018-01-14 01:20

  本文關(guān)鍵詞：電化學(xué)和水熱沉積法制備膜電極材料及其電化學(xué)性能研究　出處：《寧夏大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 超級電容器 金屬有機骨架材料 金屬硫化物 電化學(xué)合成法 水熱法

【摘要】：由于環(huán)境的日益惡化、溫室效應(yīng)的加劇和化石燃料的耗盡,發(fā)展新能源產(chǎn)業(yè)已經(jīng)迫在眉睫,其中高性能的能量存儲和轉(zhuǎn)換材料是關(guān)鍵技術(shù)之一。超級電容器因其高功率密度、可快速充放電以及循環(huán)壽命長等諸多優(yōu)點受到了廣泛關(guān)注。在制備電極材料的過程中通常需要加入粘結(jié)劑來增強電極材料與集流體之間的黏附性,但是也會因此而堵塞電極材料的孔道,減少有效孔道面積。為了解決這一問題,本論文利用電化學(xué)和水熱沉積法分別在泡沫鎳和鐵片上直接生長制備Ni-MOFs和硫化鐵薄膜電極,在無需添加任何粘結(jié)劑的情況下,提高了材料的利用率。本文研究了合成工藝參數(shù)與電化學(xué)性能之間的關(guān)系,為進(jìn)一步優(yōu)化工藝參數(shù),改進(jìn)材料性能提供了科學(xué)依據(jù)。本論文主要包括以下兩個方面的研究內(nèi)容：(1)以泡沫鎳為集流體和鎳源,均苯三甲酸為配體,蒸餾水和無水乙醇混合溶液為溶劑,氟化銨為電解質(zhì),通過電化學(xué)合成法在泡沫鎳基底上直接生長出Ni-MOFs膜電極材料。研究了不同的電化學(xué)合成時間、電流密度、溫度和電解液配比對制備Ni-MOFs泡沫鎳薄膜電極的影響,利用X-射線衍射(XRD),掃描電鏡(SEM)對其進(jìn)行了結(jié)構(gòu)表征。研究表明,在不單獨加入鎳源的情況下,可以在泡沫鎳孔道中生長一層Ni-MOFs的針狀晶體。負(fù)載量隨電化學(xué)時間和電流密度的增加而增加。通過循環(huán)伏安法,恒流充放電法和電化學(xué)阻抗譜技術(shù)測試了該電極材料的電化學(xué)性能。結(jié)果表明：在掃速為10mV/s時,Ni-MOFs的比電容僅為25.63 F/g。在掃速為10 mV/s下,經(jīng)過500次循環(huán)測試之后電容保持率為63.68%。為了提高材料的比電容,以Ni-MOFs為前驅(qū)體,通過高溫處理得到了NiOx/C復(fù)合材料,研究了不同的熱解溫度對電極材料性能的影響。Ni-MOFs電極碳化后轉(zhuǎn)化成為Ni/NiOx/C復(fù)合電極材料,碳化溫度為900℃時,所得Ni/NiOx@C復(fù)合材料的電化學(xué)性能最佳。在掃速為10 mV/s時,碳化樣品的比電容達(dá)到224.56 F/g。在掃速為10 mV/s下,經(jīng)過500次循環(huán)測試之后電容保持率為92.83%。優(yōu)化得到電化學(xué)合成的工藝參數(shù)為電流密度7 mA/cm2、溫度60℃、時間10h和電解液配比為1：1。(2)以鐵片作為集流體,FeCl2·4H2O鐵源,分別以H2NCSNH2和C2H5NS為硫源,通過水熱法在鐵片上生長硫化鐵薄膜電極材料。研究了不同硫源、鐵源濃度、水熱溫度和水熱時間對FeS納米片生長的影響,并對該電極材料進(jìn)行結(jié)構(gòu)表征和電化學(xué)性能測試。結(jié)果表明,以H2NCSNH2為硫源,水熱溫度在200℃,水熱時間在36 h時,合成的FeS納米片結(jié)晶性較好,物相單一。在掃速為10 mV/s下,樣品的比電容為66.10 F/g。在掃速為10 mV/s下,經(jīng)過1000次循環(huán)之后,FeS納米片樣品的電容保持率為89.30%。以C2H5NS為硫源,水熱溫度在165℃,水熱時間在36 h時,合成的FeS納米片結(jié)晶性較好,物相單一,沒有雜相。在掃速為10 mV/s下,樣品的比電容為65.83 F/g。在掃速為10 mV/s下,經(jīng)過1000次循環(huán)之后,FeS納米片樣品的電容保持率在87.20%。
[Abstract]:Due to the worsening of the environment, the intensification of the greenhouse effect and the depletion of fossil fuels, the development of new energy industry is imminent. High performance energy storage and conversion materials are one of the key technologies. Supercapacitors have high power density. Many advantages such as rapid charging and discharging and long cycle life have attracted much attention. In the process of preparing electrode materials it is usually necessary to add binder to enhance the adhesion between electrode materials and collector. However, it will also block the holes of electrode materials and reduce the effective pore area. In order to solve this problem. In this paper, Ni-MOFs and iron sulfide thin film electrodes were prepared by electrochemical and hydrothermal deposition on nickel foams and iron substrates, respectively, without adding any binder. The relationship between the synthesis process parameters and electrochemical properties was studied in order to further optimize the process parameters. Improving the properties of the materials provides a scientific basis. This paper mainly includes the following two aspects of research: 1) foam nickel as a fluid and nickel source, trimethoic acid as ligands. Distilled water and anhydrous ethanol were mixed as solvent and ammonium fluoride as electrolyte. Ni-MOFs film electrode materials were directly grown on nickel foam substrate by electrochemical synthesis method. Different electrochemical synthesis time and current density were studied. The effect of temperature and electrolyte ratio on the preparation of Ni-MOFs foamed nickel film electrode was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Without adding nickel source alone, a layer of needle-like crystal of Ni-MOFs can be grown in the foamed nickel channel. The loading amount increases with the increase of electrochemical time and current density, and the cyclic voltammetry is used. The electrochemical properties of the electrode were measured by constant current charge-discharge method and electrochemical impedance spectroscopy. The results show that the scanning speed is 10 MV / s. The specific capacitance of Ni-MOFs is only 25.63 F / g, and the sweep speed is 10 mV/s. After 500 cycles, the capacitance retention rate is 63.68. In order to improve the specific capacitance of the material, NiOx/C composites were obtained by high temperature treatment with Ni-MOFs as the precursor. The effect of different pyrolysis temperature on the properties of electrode materials was studied. Ni-MOFs electrode was carbonized and converted into Ni/NiOx/C composite electrode material, and the carbonation temperature was 900 鈩，

本文編號：1421403