本文選題：氧化 + 穩(wěn)定　； 參考：《北京有色金屬研究總院》2014年碩士論文

【摘要】：氧化鈧穩(wěn)定氧化鋯(ScSZ)具有優(yōu)良的氧離子傳導(dǎo)性能,已經(jīng)成為中溫固體氧化物燃料電池(SOFC)首選的新型電解質(zhì)材料。近年來,隨著美國、日本在中溫SOFC的技術(shù)發(fā)展,推動了對ScSZ粉體的應(yīng)用。目前,國內(nèi)外對ScSZ粉體制備技術(shù)的研究報道較少,商業(yè)化的粉體主要由日本第一稀有元素公司提供,而國內(nèi)產(chǎn)品存在電導(dǎo)率低、批次不穩(wěn)定等缺點(diǎn)。因此,開展高性能ScSZ粉體材料制備及其合成過程機(jī)理研究具有重要意義。 本文選擇易于工業(yè)化的氯化物體系,采用共沉淀法合成ScSZ前驅(qū)體,分別研究了微波水熱法及高溫分解法后處理過程對ScSZ目標(biāo)粉體性能的影響。主要研究內(nèi)容及結(jié)果如下： (1)研究了pH值對鋯化合物沉淀過程的影響,結(jié)果表明隨著pH值增加,粉體的硬團(tuán)聚現(xiàn)象逐漸增加,但在高pH條件下沉淀得到的粉體一次粒徑的均勻性較好。 (2)研究了pH值對鈧化合物沉淀體系的影響,結(jié)果表明pH值較低時,Cl-參與反應(yīng)生成的Sc(OH)2.6Cl0.4-H20結(jié)構(gòu)阻礙前驅(qū)體γ-ScOOH.nH2O薄片的生長,隨著pH值的增加該影響逐漸減弱。 (3)為了得到均勻的鈧鋯鈰共沉淀粉體,研究了鈧鋯鈰混合沉淀體系的Zeta電位變化規(guī)律,并結(jié)合該體系的Ksp,確定合理的混合體系沉淀pH值為8-9之間。利用在線顆粒分析系統(tǒng)FBRM和PVM對共沉淀過程進(jìn)行實時圖像及粒徑分析,發(fā)現(xiàn)在常溫條件下反應(yīng)體系主要發(fā)生無定形沉淀。同時研究了高溫陳化對反應(yīng)體系中的晶體生長的影響,發(fā)現(xiàn)高溫條件下晶體呈一維方向生長,但晶體結(jié)構(gòu)不穩(wěn)定,烘干后晶體坍塌轉(zhuǎn)為無定型態(tài)。 (4)研究了微波水熱法和高溫分解法對ScSZ前驅(qū)體進(jìn)行后處理研究。高溫分解研究結(jié)果表明,煅燒溫度為420℃～1000℃區(qū)間均可獲得立方相結(jié)構(gòu),通過球磨后該粉體的粒徑小且分布均勻,壓制陶瓷片的電導(dǎo)率為170.50ms/cm,通過二次焙燒處理后,電導(dǎo)率進(jìn)一步提高到180.25ms/cm。微波水熱條件試驗表明,在水熱溫度為150℃、水熱時間為2.5h、添加礦化劑下制備出結(jié)晶度好、比表面積高的粉體,其中值粒徑Dso為6.1pmm,粒徑分布(D90-D1o)/2D5o為1.0,壓制陶瓷片的電導(dǎo)率為125.65ms/cm,低于高溫分解球磨后的粉體,不過從能耗方面考慮,微波水熱法仍具有一定的發(fā)展?jié)摿Α?br/>[Abstract]:Scandium-stabilized zirconia (ScSZ) has become the preferred electrolyte material for medium temperature solid oxide fuel cells (SOFC) due to its excellent oxygen ion conductivity. In recent years, with the development of medium temperature SOFC technology in America and Japan, the application of ScSZ powder has been promoted. At present, there are few reports on the preparation technology of ScSZ powder at home and abroad. The commercial powder is mainly supplied by the first rare element Company of Japan. However, the domestic products have the disadvantages of low conductivity and unstable batch. Therefore, it is of great significance to study the preparation and synthesis mechanism of high performance ScSZ powder. In this paper, ScSZ precursor was synthesized by coprecipitation method in chloride system which is easy to industrialize. The effects of microwave hydrothermal method and high temperature decomposition process on the properties of ScSZ target powder were studied. The main contents and results are as follows: (1) the effect of pH value on the precipitation process of zirconium compounds is studied. The results show that the hard agglomeration of powders increases with the increase of pH value. However, the uniformity of the primary particle size of the powders obtained by precipitation at high pH was better. (2) the effect of pH value on the precipitation system of scandium compounds was studied. The results show that the SC (OH) 2.6Cl0.4-H20 structure of the precursor 緯 -ScOH.nH2O is hindered when pH value is low. (3) in order to obtain homogeneous Scandium zirconium cerium coprecipitation powder, the growth of precursor 緯 -ScOH.nH2O wafer is gradually weakened with the increase of pH value. The Zeta potential of the mixed precipitation system of scandium zirconium and cerium was studied and the pH value of the mixed system was determined to be between 8-9. The real-time image and particle size analysis of the coprecipitation process were carried out by using the on-line particle analysis systems FBRM and PVM. It was found that the amorphous precipitation occurred mainly in the reaction system at room temperature. At the same time, the effect of aging on the crystal growth in the reaction system is studied. It is found that the crystal grows in one-dimensional direction at high temperature, but the crystal structure is unstable. The crystal collapses into an amorphous state after drying. (4) the microwave hydrothermal method and the high temperature decomposition method were studied for the post-treatment of ScSZ precursor. The results of high temperature decomposition show that the cubic phase structure can be obtained at the range of 420 鈩，

本文編號：2092869