【作者】 吕振刚；

【导师】 郭瑞松；

【作者基本信息】 天津大学 ， 无机非金属材料学， 2004， 硕士

【摘要】 作为一种新型发电方式,固体氧化物燃料电池（SOFC）的潜力是相当巨大的。发展中温SOFC成为SOFC研究与开发的热点和趋势。本实验通过对ZrO₂电解质材料进行多元复合掺杂改性系统研究,造成晶格畸变,增大氧空位迁移通道R,提高试样电导率,以期用于中温SOFC。采用传统高温固溶法制备了Y₂O₃、Yb₂O₃、Sc₂O₃（Dy₂O₃）、Al₂O₃和CaO多元复合掺杂的ZrO₂固体电解质材料。在ZrO₂中添加适量由Y₂O₃、Yb₂O₃、Sc₂O₃（Dy₂O₃）组成的复合掺杂剂,当复合添加组成为8⁸.6mol%时,试样电导率得到显著提高（ 1000℃, 0.19S/cm）,电导活化能降低,该材料在1000℃下工作,运行900h时仍具有较高电导率（约0.15S/cm）,具有较好的抗衰老性。然而,该材料的烧结性（相对密度约95%）和强度（弯曲强度约100MPa）有待于提高,因此继续添加少量Al₂O₃,CaO以及二者的混合物。结果表明,少量Al₂O₃对材料电性能影响较小,但提高了试样的相对密度（².3%）和强度（³0%）;少量CaO的添加虽然使材料的相对密度略微增大,但却降低了试样电导率（⁵0%）和强度。采用燃烧法制备相同组成的复合掺杂ZrO₂材料,以期提高组分均匀性和烧结活性。由于多元组分反应复杂,使得材料各方面性能未能体现出应有的优势,试样1000℃电导率达0.15S/cm,相对密度（约94%）和强度均较低。更多还原

【Abstract】 As a new way of power generation, Solid Oxide Fuel Cell (SOFC)has caused a wide attention in recent years. The development of IT-SOFChas been the hot issues and has become the tendency for the research anddevelopment of SOFC. In this paper, The ZrO2 doped by multi-elementswas studied, which made crystal lattice distorsion and enhanced theoxygen vacancy transfer passage radii and conductivity. This material isexpected to be used for the electrolyte of IT-SOFC.The ZrO2 electrolyte materials doped by multi-elements (Y2O3,Sc2O3, Dy2O3, Yb2O3, Al2O3 and CaO) were prepared byhigh-temperature solid-state method. The high-temperature conductivityof samples was enhanced remarkably, reaching 0.19S/cm at 1000°C, withthe total additives in the range of 8~8.6mol%. The aging property wasgood, the high-temperature conductivity (1000°C) remained about0.15S/cm after working for 900h. While the sinterability (relative density,~95%) and bending strength would be enhanced. It is expected thatsinterability and mechanical property can be further improved byinclusion of small amount of Al2O3 and/or CaO into the multi-elementsdoped ZrO2 materials. The addition of some amount of Al2O3 reduced theconductivity a little, but enhanced relative density (~2.3%) and bendingstrength (~30%) of samples respectively. The addition of some amount ofCaO reduced bending strength and conductivity (~50%) of samples.The same compositions samples were prepared by combustionsynthesis, in order to improve the samples sinterability further and makemulti-elements mix well. All properties of samples didn’t show their ownadvantages due to the complexity of the reaction among all elements. Thehigh-temperature conductivity reached 0.15S/cm, but the relative density(~94%) and bending strength were lower than that the same compositionssamples prepared by high-tempreture solid-state method.更多还原