Grain boundary segregation and its influences on ionic conduction properties of scandia doped zirconia electrolytes
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摘要
Solid oxide fuel cell is a promising energy conversion system which converts chemical energy into electrical energy directly. Electrolyte is the key component and determines the working temperature. In this paper,ceria and scandia co-doped zirconia electrolytes sintered from 1300 to 1550 ℃ were chosen as research objects. Scanning electron microscopy, X-ray diffraction and transmission electron microscopy were performed to characterize the ceramic samples. The effects of grain size and grain boundary element segregation on the electrical conductivity were focused. Electrochemical impedance spectroscopy was used to calculate the bulk, grain boundary and specific grain boundary conductivity. Results show that the bulk and grain boundary ionic conductivity increases with the increasing grain size.However, the specific grain boundary conductivity decreases with the increasing grain size. This is explained by the fact that Sc~(3+) is segregated at the grain boundary, which leads to higher oxygen vacancy concentration when sintered at lower temperature.
Solid oxide fuel cell is a promising energy conversion system which converts chemical energy into electrical energy directly. Electrolyte is the key component and determines the working temperature. In this paper,ceria and scandia co-doped zirconia electrolytes sintered from 1300 to 1550 ℃ were chosen as research objects. Scanning electron microscopy, X-ray diffraction and transmission electron microscopy were performed to characterize the ceramic samples. The effects of grain size and grain boundary element segregation on the electrical conductivity were focused. Electrochemical impedance spectroscopy was used to calculate the bulk, grain boundary and specific grain boundary conductivity. Results show that the bulk and grain boundary ionic conductivity increases with the increasing grain size.However, the specific grain boundary conductivity decreases with the increasing grain size. This is explained by the fact that Sc~(3+) is segregated at the grain boundary, which leads to higher oxygen vacancy concentration when sintered at lower temperature.
Solid oxide fuel cell is a promising energy conversion system which converts chemical energy into electrical energy directly. Electrolyte is the key component and determines the working temperature. In this paper,ceria and scandia co-doped zirconia electrolytes sintered from 1300 to 1550 ℃ were chosen as research objects. Scanning electron microscopy, X-ray diffraction and transmission electron microscopy were performed to characterize the ceramic samples. The effects of grain size and grain boundary element segregation on the electrical conductivity were focused. Electrochemical impedance spectroscopy was used to calculate the bulk, grain boundary and specific grain boundary conductivity. Results show that the bulk and grain boundary ionic conductivity increases with the increasing grain size.However, the specific grain boundary conductivity decreases with the increasing grain size. This is explained by the fact that Sc~(3+) is segregated at the grain boundary, which leads to higher oxygen vacancy concentration when sintered at lower temperature.
引文
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2. Choudhary T, Sanjay. Novel and optimal integration of SOFC-ICGT hybrid cycle:energy analysis and entropy generation minimization. Int J Hydrog Energy.2017;42(23):15597.
3. Sharma RK, Burriel M, Dessemond L, Bassat JM, Djurado E. Design of interfaces in efficient Ln_2NiO_(4+δ)(Ln=La, Pr)cathodes for SOFC applications. J Mater Chem A. 2017;4(32):12451.
4. Jais AA, Ali SAM, Anwar M, Somalu MR, Muchtar A, Wan NRWI, et al. Enhanced ionic conductivity of scandia-ceria-stabilized-zirconia(lOSc1CeSZ)electrolyte synthesized by the microwave-assisted glycine nitrate process. Ceram Int.2017;43(11):8119.
5. Cai GF, Gu YH, Ge L, Zhang YL, Chen H, Guo LC. Modification of electrolyte surface with"windows"and"dimples array"structure for SOFC based on YSZ electrolyte. Ceram Int. 2017;43(12):8944.
6. Bhabu KA, Theerthagiri J, Madhavan J, Balu T, Rajasekaran TR. Superior oxide ion conductivity of novel acceptor doped cerium oxide electrolytes for IT-SOFC applications. J Phys Chem C. 2016;120(33):18452.
7. Yu FY, Zhang YP, Yu L, Cai WZ, Yuan LL, Liu J, et al. All-solid-state direct carbon fuel cells with thin yttrium-stabilized-zirconia electrolyte supported on nickel and iron bimetal-based anodes. Int J Hydrog Energy. 2016;41(21):9048.
8. West AR, Hernandez MA. Dipolar relaxation and the impedance of yttriastabilised zirconia ceramic electrolyte. J Mater Chem. 2016;4(4):1298.
9. Tien TY. Grain boundary conductivity of Zr_(0.84)Ca_(0.16)O_(1.84)ceramics. J Appl Phys.1964;35(1):122.
10. Chen XJ, Khor KA, Chan SH, Yu LG. Influence of micro structure on the ionic conductivity of yttria-stabilized zirconia electrolyte. Mater Sci Eng A.2002;335(1):246.
11. Kumar A, Jaiswal A, Sanbui M, Omar S. Oxygen-ion conduction in scandiastabilized zirconia-ceria solid electrolyte(xSc_2O_3-1 CeO_2-(99-x)ZrO_2,5≤x≤11). J Am Ceram Soc. 2016;100(2):659.
12. Guo X, Zhang ZL Grain size dependent grain boundary defect structure:case of doped zirconia. Acta Mater. 2003;51(9):2539.
13. Tao JC, Dong AP, Wang J. The influence of microstructure and grain boundary on the electrical properties of scandia stabilized zirconia. Mater T. 2013;54(5):825.
14. Tao JC, Hao Y, Wang J. The research of crystal structure and electrical properties of a new electrolyte material:scandia and Holmia stabilized zirconia. J Ceram Soc Jap. 2013;121(1411):317.
15. Hansen KV, Mogensen M. Absence of dopant segregation to the surface of scandia and yttria co-stabilized zirconia. Electrochem Solid State Lett.2012;15(5):B70.
16. Smirnova A, Sadykov V, Muzykantov V, Mezentseva N, Ivanov V, Zaikovskii V,et al. Scandia-stabilized zirconia:effect of dopants on surface/grain boundarysegregation and transport properties. Boston:Mrs Online Proceeding Library;2011:972.
17. Mori M, Itoh T. Long annealing effect on stabilities for electrical conductivity of(ZrO_2)_(0.89)(Sc_2O_3)_(0.1)(CeO_2)_(0.01)electrolyte at IT-SOFC operating temperature. ECS Trans. 2013;57(1):1107.
18. Bohnke O, Gunes V, Kravchyk KV, Belous AG, Yanchevskii OZ, V'Yunov OI. Ionic and electronic conductivity of 3 mol%Fe_2O_3-substituted cubic yttria-stabilized ZrO_2(YSZ)and scandia-stabilized ZrO_2(ScSZ). Solid State Ionics. 2014;262(9):517.
19. Lei YY, Ito Y, Browning ND, Mazanec TJ. Segregation effects at grain boundaries in fluorite-structured ceramics. J Am Ceram Soc. 2002;85(9):2359.
20. Idris MA, Bak T, Li S, Nowotny J. Effect of segregation on surface and nearsurface chemistry of yttria-stabilized zirconia. J Phys Chem C. 2012;116(20):10950.
21. Zhang F, Batuk M, Hadermann J, Manfredi G, An M, Vanmeensel K, et al. Effect of cation dopant radius on the hydrothermal stability of tetragonal zirconia:grain boundary segregation and oxygen vacancy annihilation. Acta Mater.2016;106:48.
22. Feng B, Yokoi T, Kumamoto A, Yoshiya M, Ikuhara Y, Shibata N. Atomically ordered solute segregation behaviour in an oxide grain boundary. Nat Commun.2016;7:11079.
23. Du K, Hoon KC, Heuer A, Goettler R, Liu Z. Structural evolution and electrical properties of Sc_2O_3-stabilized ZrO_2 aged at 850℃in air and wet-forming gas ambients. J Am Ceram Soc. 2008;91(5):1626.
24. Abdala PM, Custo GS, Lamas DG. Enhanced ionic transport in fine-grained scandia-stabilized zirconia ceramics. J Power Sources. 2010;195(11):3402.
25. Guo X, Waser R. Electrical properties of the grain boundaries of oxygen ion conductors:acceptor-doped zirconia and ceria. Prog Mater Sci. 2006;51(2):151.
26. Choi SW, Kim KJ, Kim MY, Lim J, Yang SH, Kim YS, et al. Effect of ceria content of CeScSZ powder on the phase stability and electrical conductivity of SOFC electrolyte. ECS T. 2015;68(1):405.
27. Zhang JX, Huang XW, Zhang H, Xue QN, Xu H, Wang LS, et al. The effect of powder grain size on the microstructure and electrical properties of 8 mol%Y203-stabilized Zr02. RSCAdv. 2017;7(62):39153.
28. Cao WW, Randall CA. Grain size and domain size relations in bulk ceramic ferroelectric materials. J Phys Chem Solid. 1996;57(10):1499.
29. Hu LF, Wang CA. Effect of sintering temperature on compressive strength of porous yttria-stabilized zirconia ceramics. Ceram Int. 2010;36(5):1697.
30. Fujimori H, Yashima M, Kakihana M, Yoshimura M. Structural changes of scandia-doped zirconia solid solutions:rietveld analysis and Raman scattering.J Am Ceram Soc. 2010;81(11):2885.
31. Kwon OH, Jang C, Lee J, Hu YJ, Kwon YI, Joo JH, et al. Investigation of the electrical conductivity of sintered monoclinic zirconia(ZrO_2). Ceram Int.2017;43(11):8236.
2. Choudhary T, Sanjay. Novel and optimal integration of SOFC-ICGT hybrid cycle:energy analysis and entropy generation minimization. Int J Hydrog Energy.2017;42(23):15597.
3. Sharma RK, Burriel M, Dessemond L, Bassat JM, Djurado E. Design of interfaces in efficient Ln_2NiO_(4+δ)(Ln=La, Pr)cathodes for SOFC applications. J Mater Chem A. 2017;4(32):12451.
4. Jais AA, Ali SAM, Anwar M, Somalu MR, Muchtar A, Wan NRWI, et al. Enhanced ionic conductivity of scandia-ceria-stabilized-zirconia(lOSc1CeSZ)electrolyte synthesized by the microwave-assisted glycine nitrate process. Ceram Int.2017;43(11):8119.
5. Cai GF, Gu YH, Ge L, Zhang YL, Chen H, Guo LC. Modification of electrolyte surface with"windows"and"dimples array"structure for SOFC based on YSZ electrolyte. Ceram Int. 2017;43(12):8944.
6. Bhabu KA, Theerthagiri J, Madhavan J, Balu T, Rajasekaran TR. Superior oxide ion conductivity of novel acceptor doped cerium oxide electrolytes for IT-SOFC applications. J Phys Chem C. 2016;120(33):18452.
7. Yu FY, Zhang YP, Yu L, Cai WZ, Yuan LL, Liu J, et al. All-solid-state direct carbon fuel cells with thin yttrium-stabilized-zirconia electrolyte supported on nickel and iron bimetal-based anodes. Int J Hydrog Energy. 2016;41(21):9048.
8. West AR, Hernandez MA. Dipolar relaxation and the impedance of yttriastabilised zirconia ceramic electrolyte. J Mater Chem. 2016;4(4):1298.
9. Tien TY. Grain boundary conductivity of Zr_(0.84)Ca_(0.16)O_(1.84)ceramics. J Appl Phys.1964;35(1):122.
10. Chen XJ, Khor KA, Chan SH, Yu LG. Influence of micro structure on the ionic conductivity of yttria-stabilized zirconia electrolyte. Mater Sci Eng A.2002;335(1):246.
11. Kumar A, Jaiswal A, Sanbui M, Omar S. Oxygen-ion conduction in scandiastabilized zirconia-ceria solid electrolyte(xSc_2O_3-1 CeO_2-(99-x)ZrO_2,5≤x≤11). J Am Ceram Soc. 2016;100(2):659.
12. Guo X, Zhang ZL Grain size dependent grain boundary defect structure:case of doped zirconia. Acta Mater. 2003;51(9):2539.
13. Tao JC, Dong AP, Wang J. The influence of microstructure and grain boundary on the electrical properties of scandia stabilized zirconia. Mater T. 2013;54(5):825.
14. Tao JC, Hao Y, Wang J. The research of crystal structure and electrical properties of a new electrolyte material:scandia and Holmia stabilized zirconia. J Ceram Soc Jap. 2013;121(1411):317.
15. Hansen KV, Mogensen M. Absence of dopant segregation to the surface of scandia and yttria co-stabilized zirconia. Electrochem Solid State Lett.2012;15(5):B70.
16. Smirnova A, Sadykov V, Muzykantov V, Mezentseva N, Ivanov V, Zaikovskii V,et al. Scandia-stabilized zirconia:effect of dopants on surface/grain boundarysegregation and transport properties. Boston:Mrs Online Proceeding Library;2011:972.
17. Mori M, Itoh T. Long annealing effect on stabilities for electrical conductivity of(ZrO_2)_(0.89)(Sc_2O_3)_(0.1)(CeO_2)_(0.01)electrolyte at IT-SOFC operating temperature. ECS Trans. 2013;57(1):1107.
18. Bohnke O, Gunes V, Kravchyk KV, Belous AG, Yanchevskii OZ, V'Yunov OI. Ionic and electronic conductivity of 3 mol%Fe_2O_3-substituted cubic yttria-stabilized ZrO_2(YSZ)and scandia-stabilized ZrO_2(ScSZ). Solid State Ionics. 2014;262(9):517.
19. Lei YY, Ito Y, Browning ND, Mazanec TJ. Segregation effects at grain boundaries in fluorite-structured ceramics. J Am Ceram Soc. 2002;85(9):2359.
20. Idris MA, Bak T, Li S, Nowotny J. Effect of segregation on surface and nearsurface chemistry of yttria-stabilized zirconia. J Phys Chem C. 2012;116(20):10950.
21. Zhang F, Batuk M, Hadermann J, Manfredi G, An M, Vanmeensel K, et al. Effect of cation dopant radius on the hydrothermal stability of tetragonal zirconia:grain boundary segregation and oxygen vacancy annihilation. Acta Mater.2016;106:48.
22. Feng B, Yokoi T, Kumamoto A, Yoshiya M, Ikuhara Y, Shibata N. Atomically ordered solute segregation behaviour in an oxide grain boundary. Nat Commun.2016;7:11079.
23. Du K, Hoon KC, Heuer A, Goettler R, Liu Z. Structural evolution and electrical properties of Sc_2O_3-stabilized ZrO_2 aged at 850℃in air and wet-forming gas ambients. J Am Ceram Soc. 2008;91(5):1626.
24. Abdala PM, Custo GS, Lamas DG. Enhanced ionic transport in fine-grained scandia-stabilized zirconia ceramics. J Power Sources. 2010;195(11):3402.
25. Guo X, Waser R. Electrical properties of the grain boundaries of oxygen ion conductors:acceptor-doped zirconia and ceria. Prog Mater Sci. 2006;51(2):151.
26. Choi SW, Kim KJ, Kim MY, Lim J, Yang SH, Kim YS, et al. Effect of ceria content of CeScSZ powder on the phase stability and electrical conductivity of SOFC electrolyte. ECS T. 2015;68(1):405.
27. Zhang JX, Huang XW, Zhang H, Xue QN, Xu H, Wang LS, et al. The effect of powder grain size on the microstructure and electrical properties of 8 mol%Y203-stabilized Zr02. RSCAdv. 2017;7(62):39153.
28. Cao WW, Randall CA. Grain size and domain size relations in bulk ceramic ferroelectric materials. J Phys Chem Solid. 1996;57(10):1499.
29. Hu LF, Wang CA. Effect of sintering temperature on compressive strength of porous yttria-stabilized zirconia ceramics. Ceram Int. 2010;36(5):1697.
30. Fujimori H, Yashima M, Kakihana M, Yoshimura M. Structural changes of scandia-doped zirconia solid solutions:rietveld analysis and Raman scattering.J Am Ceram Soc. 2010;81(11):2885.
31. Kwon OH, Jang C, Lee J, Hu YJ, Kwon YI, Joo JH, et al. Investigation of the electrical conductivity of sintered monoclinic zirconia(ZrO_2). Ceram Int.2017;43(11):8236.