Sr和Nd掺杂对La_(9.33)(SiO_4)_6O_2电解质性能的影响  

Influence of Sr and Nd doping on performance of apatite La_(9.33)(SiO_4)_6O_2 electrolyte

作　　者：陈亚男[1] 喻俊[1] 黄志良[1] 胡威峰[1] 鲁冕[1] 田兴[1] 

机构地区：[1]武汉工程大学材料与科学与工程学院,湖北武汉430074

出　　处：《武汉工程大学学报》2011年第9期39-45,共7页Journal of Wuhan Institute of Technology

基　　金：湖北省教育厅重大项目(Z20091501);国家自然科学基金项目(50874081)

摘　　要：采用尿素-硝酸盐燃烧法对磷灰石型LSO电解质进行了三价稀土元素Nd和二价碱土元素Sr的La位掺杂,对合成样品进行XRD、SEM分析表征,并测试和分析了样品的电导率.结果表明:Sr、Nd掺杂对LSO的晶体结构、物相和形貌产生的影响很小,而适量的掺杂可有效提高LSO的氧离子传输性能.当掺杂x=0.3时,La9.33Mx(SiO4)6O2+δ(M=Sr、Nd)具有最高离子电导率,La9.33M0.3(SiO4)6O2+δ在500℃时的电导率分别为7.248×10-3S.cm-1、1.782×10-2S.cm-1.Nd掺杂不仅可以提高电导率,还可以降低传导活化能,相比于Sr掺杂更有利于LSO在中低温SOFCs中的应用.实验认为,Sr、Nd掺杂的LSO属于间隙氧传导机制,掺杂可以提高间隙氧的数量,间隙氧相比阳离子空位对LSO电导率的影响更大.The urea-nitrates combustion was introduced to prepare the LSO conductor doped three valence rare earth elements Nd and bivalent alkaline elements Sr at La bits.The synthetic samples were characterized by XRD,SEM etc,and while the conductivity of the samples was tested and analyzed.The results proclaimed that there were little effects of Sr and Nd doping on the crystal structure,phase and morphology of LSO.However,the transport properties of oxygen ion could be improved efficiently by proper amounts of Sr and Nd dopants.When the doping concentration x was 0.3,La9.33Mx（SiO4）6O2＋δ（M=Sr、Nd） showed the highest conductivity of 7.248×10-3 S·cm-1 and 1.782×10-2 S·cm-1 at 500 ℃.It showed that Nd doping not only enhanced the ionic conductivity,but also reduced the conduction activation energy,which was more favorable for application of LSO in intermediate temperature SOFCs comparing with the Sr doping.It can be concluded that Sr and Nd doped LSO via interstitial oxygen ion conduction mechanism,which produced a more effect on the conductivity than cation vacancy.The oxygen ion conductivity was improved because Sr and Nd doping increased the amounts of interstitial oxygen.

关 键 词：燃烧合成 硅酸镧 固体电解质 掺杂 离子电导率 

分 类 号：Q611.4[生物学—生物物理学] Q653