Influence of Gd2O3 doping contents on conductivity of Ce1-xGdxO2-δ electrolyte
Yuan-yuan LIU1,2,3, Shu-ting LI1,2, Jun PENG1,2, Sheng-li AN1,2,*()
1 School of Materials and Metallurgy, Inner Mongolia University of Science and Technology, Baotou 014010, Inner Mongolia, China 2 Inner Mongolia Key Laboratory of Advanced Ceramic Materials and Devices, Baotou 014010, Inner Mongolia, China 3 College of Chemistry and Chemical Engineering, Inner Mongolia University of Science and Technology, Baotou 014010, Inner Mongolia, China
Gd2O3 doped CeO2(GDC) was widely used in solid oxide fuel cell (SOFC) because of its high ionic conductivity at 500-700 ℃. However, during the SOFC operation, Ce4+ was reduced to Ce3+ at the anode side of the battery, resulting in electronic leakage, which leaded to the degradation of SOFC battery performance. The Ce1-xGdxO2-δ(x=0.05, 0.10, 0.15, 0.20, 0.25, mole fraction) solid electrolyte was prepared by sol-gel method. The effects of different Gd3+ doping amount on the total conductivity and electronic conductivity of GDC electrolyte were studied, and the relationships between the total conductivity, electronic conductivity, and temperature, oxygen partial pressure were analyzed. The results show that, when the Gd2O3 doping content is 0.20, the total conductivity of GDC reaches the highest 8.59×10-2 S·cm-1 at 750 ℃. The electronic conductivity decreases with the increase of Gd3+doping amount, and reaches the highest 6.47×10-4 S·cm-1 at 750 ℃ when Gd3+doping amount is 0.10. The GDC with doping amount of 0.20 highlights the highestionic conductivity because of its highest total conductivity and smaller electronic conductivity.
HAN M F , ZHANG Y L . Ceramic materials for solid oxide fuel cell[J]. Journal of the Chinese Ceramic Society, 2017, (45): 1548- 1554.
LAKSHMI V V , BAURI R , GANDHI A S , et al. Synthesis and characterization of nanocrystalline ScSZ electrolyte for SOFCs[J]. International Journal of Hydrogen Energy, 2011, 36 (22): 14936- 14942.
GUO R H , ZHANG J Y , ZHOU G Z , et al. Preparation and performance analysis of solid oxide fuel cell electrolyte Gd0.1BaxCe0.9-xO2-σ[J]. New Chemical Materials, 2017, 45 (7): 120- 122.
WUT W , JIA G X , WANG X X , et al. Transitional area of Ce4+ to Ce3+ in SmxCayCe1-x-yO2-δ with various doping and oxygen vacancy concentrations: a GGA+U study[J]. Chinese J Struct Chem, 2018, 37 (2): 198- 209.
WU T W , JIA G X , BAO J X , et al. Electronic structure and oxygen ion migration of the CaO or Bao and Sm2O3Co-doped CeO2system:a DFT + U study[J]. Chinese Journal of Inorganic Chemistry, 2016, 32 (8): 1363- 1369.
YAHIRO H , EGUCHI Y , EGUCHI K , et al. Oxygen ion conductivity of the ceria-samarium oxide system with fluorite structure[J]. Journal of Applied Electrochemistry, 1988, 18 (4): 527- 531.
YUAN Y J , ZHANG M F , LI T J , et al. Electrical properties of Ce0.8Sm0.1Nd0.1O2-σ/La10Si6O27composite electrolyte[J]. Rare Metal Materials and Engineering, 2018, 47 (1): 339- 343.
ZHANG T S , MA J , CHENG H , et al. Ionic conductivity of high-purity Gd-doped ceria solid solutions[J]. Materials Research Bulletin, 2006, 41 (3): 563- 568.
MOGENSEN M , SAMMES N M , TOMPSETT G A . Physical, chemical and electrochemical properties of pure and doped ceria[J]. Solid State Ionics, 2000, 129, 63- 94.
STEELE B C H . Appraisal of Ce1-yGdyO2-y/2 electrolytes for IT-SOFC operation at 500 ℃[J]. Solid State Ionics, 2000, 129, 95- 110.
LEE K T , YOON H S , WACHSMAN E D . The evolution of low temperature solid oxide fuel cells[J]. Journal of Materials Research, 2012, 27, 2063- 2078.
SHIMONOSONO T , HIRATA Y , EHIRA Y , et al. Electronic conductivity measurement of Sm- and La-doped ceria ceramics by Hebb-Wagner method[J]. Journal of Solid State Ionics, 2004, 174 (1/4): 27- 33.
WANG S R , TAKEHISA K , MASAYUKI D , et al. Electrical and ionic conductivity of Gd-doped ceria[J]. Journal of the Electrochemical Society, 2000, 147 (10): 3606- 3609.
QIAN J , TAO Z , XIAO J , et al. Performance improvement of ceria-based solid oxide fuel cells with yttria-stabilized zirconia as an electronic blocking layer by pulsed laser deposition[J]. International Journal of Hydrogen Energy, 2013, 38, 2407- 2412.
CHENG L , LUO L H , XU X , et al. Preparation of GDC nano-powder with different gadolinium contents by combustion method and its electrical conductivity[J]. Journal of the Chinese Ceramic Society, 2018, (3): 354- 360.