Zn BaZr 0.7 Pr 0.1 Y 0.2 O 3 δ

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1 JOURNAL OF THE CHINESE CERAMIC SOCIETY Vol. 40 No. 12 December 2012 Zn BaZr 0.7 Pr 0.1 Y 0.2 O 3 δ 1,2 1, ( ) (SOFC) BaZr 0.7 Pr 0.1 Y 0.2 O 3 δ (BZPY) BaZr 0.7 Pr 0.1 Y 0.16 Zn 0.04 O 3 δ (BZPYZn) Zn X BZPYZn h ( ) BZPYZn h BZPYZn 97.3% S/cm /K (Ni) BZPYZn SOFC TM911.4 A (2012) :09:55 Preparation and Properties of Zn Doped BaZr 0.7 Pr 0.1 Y 0.2 O 3 δ Proton-Conducting Used for Solid Electrolytes Oxide Fuel Cells GU Qingwen 1,2 WANG Xiaolian 1,2 DING Yanzhi 2 LIN Bin 2 CHEN Yonghong 2 (1. School of Chemical Engineering, Anhui University of Science and Technology, Huainan , Anhui, China; 2. Anhui Key Laboratory of Low Temperature Co-fired Materials; Department of Chemistry and Engineering, Huainan Normal University, Huainan , Anhui, China) Abstract: BaZr 0.7 Pr 0.1 Y 0.2 O 3 δ (BZPY) and BaZr 0.7 Pr 0.1 Y 0.16 Zn 0.04 O 3 δ (BZPYZn) proton-conducting solid oxide fuel cells (SOFC) electrolytes were synthesized by a citrate nitrate combustion method. The influence of Zn doped on the sintering, coefficient of thermal expansion (TEC) and electrical properties of sample were investigated. The phase and microstructure of the sintered samples were characterized by X-ray diffraction and scanning electron microscope, respectively. The results showed that BZPYZn exhibits a single perovskite structure after the calcination at for 5 h. With increasing of sintering temperatures (from to ), the grain size of BZPYZn ceramic sample increases, and porosity decreases. The high relative density of 97.3% is obtained for the BZPYZn sample sintered at for 5 h. The BZPYZn sample exhibit a high ionic conductivity (10 3 to 10 2 S/cm) at The average TEC of the BZPYZn is /K from room temperature up to 1 000, which fits well with those of electrode materials (e.g. Ni). It is indicated that BZPYZn is a promising candidate as a stable and easily sintered electrolyte for intermediatetemperature SOFC. Key works: intermediate-temperature solid oxide fuel cell; proton conducting; electrolyte; zinc dopant; conductivity (solid oxide fuel cells SOFCs) (1206c ) ( ) (2010A03203) (1987 ) (1962 ) Received date: Revised date: First author: GU Qingwen (1987 ), male, Master candidate. guqingwen1987@163.com Correspondent author: CHEN Yonghong (1962 ), male, Professor. chenyh@hnnu.edu.cn

2 40 12 Zn BaZr 0.7 Pr 0.1 Y 0.2 O 3 δ 1829 [1 2] SOFCs ( ) [3] SOFC ( ) (IT-SOFC) [4 7] [8] Y ZrO 2 (YSZ) Gd CeO 2 (GDC) Sm CeO 2 (SDC) SOFC SOFC [9 14] SOFC SrCeO 3 BaCeO 3 CaZrO 3 BaZrO 3 LnScO 3 (Ln = La Nd Sm Gd) [15] (1 700 ) [16] Fabbri [17] Pr BaZr 0.7 Pr 0.1 Y 0.2 O 3 δ (BZPY) h 1.7 μm BZPY ( S/cm) BZPY [18] Babilo [19] Tao [10] Zn Y Zr BaCeO 3 Zn BaCeO 3 CO 2 H 2 O BaZr 0.7 Pr 0.1 Y 0.16 Zn 0.04 O 3 δ (BZPYZn) Zn Ba(NO 3 ) 2 ( ) Zr(NO 3 ) 4 5H 2 O Pr(NO 3 ) 3 6H 2 O Y(NO 3 ) 3 6H 2 O Zn(NO 3 ) 2 ( ) (C 6 H H 2 O)( ) ( ) (NH 3 H 2 O)( ) ( ) ( ) BaZr 0.7 Pr 0.1 Y 0.2 O 3 δ (BZPY) BaZr 0.7 Pr 0.1 Y 0.16 Zn 0.04 O 3 δ (BZPYZn) 1 mol/l (EDTA) (ΣM Z+ ) (CA) 1:1.5 ph h MPa 13 mm 1 2 mm ( ) 2 /min 5 h BZPYZn 200 MPa (40 mm 5mm 2 mm) h 1.3 DX-2000 X Cu K α (λ = nm) 40 kv 30 ma θ Mettler Toledo TGA/SDTA 851 e TG DTG N 2 50 ml/min 10 /min KYKY EM-3200 Archimedes DIL-402C CHI-402C ( ) ( 3% ) Ag

3 TG DTG BZPYZn TG DTG % 6.73% % 782 (BaCO 3 ) CO 2 1 BZPYZn TG DTG Fig. 1 TG DTG curves for BaZr 0.7 Pr 0.1 Y 0.16 Zn 0.04 O 3 δ (BZPYZn) powder BZPYZn Zn BaZr 0.7 Pr 0.1 Y 0.2 O 3 δ (BZPY) 5 h X (XRD) 2a BZPYZn 5 h XRD 2a XRD BaCO BaCO 3 2θ= b BZPY 5 h XRD 2b BZPY h BZPYZn BZPY XRD Fig. 2 XRD patterns of the powders BZPYZn and BaZr 0.7 Pr 0.1 Y 0.2 O 3 δ (BZPY) calcined at different temperatures for 5 h 5 h BaCO 3 BaCO BaCO 3 2θ = CaTiO 3 (JCPDF ) 2a 2b BZPYZn BZPY BZPY Y Zn Zn BZPY SEM 3 BZPYZn 5 h

4 40 12 Zn BaZr 0.7 Pr 0.1 Y 0.2 O 3 δ h 2.4 BZPYZn Zn 200 Babilo [19] Tao [10] Zn mm BZPYZn 5h % 1 5 h BZPYZn Table 1 Shrinkage of samples BZPYZn sintered at different temperatures for 5 h Temperature/ Diameter/ mm Sample wafer 1 Sample wafer 2 Shrinkage/% Diameter/ mm Shrinkage/% Note: Before sintering, size of BZPYZn sample wafer is 13 mm in diameter and 1 2 mm thick. Sample wafer 1 and sample wafer 2 represent two samples sintered at different temperatures for 5 h. 3 5 h BZPYZn SEM Fig. 3 SEM micrographs of fractured surface of BZPYZn sintered at different temperatures for 5 h SEM h μm h BZPYZn 5 h % 97.3% % h h BZPYZn H 2 Arrhenius a 5a BZPYZn H

5 1832 Table h BZPYZn Relative density and porosity of samples BZPYZn sintered at different temperatures for 5 h Temperature/ Volume density/(g cm 3 ) Theoretical density/(g cm 3 ) Relative density/% Total porosity/% BZPYZn (σ) (T) Arrhenius Fig. 4 Temperature dependence of the electrical conductivity (σ) and Arrhenius curves of electrical conductivity of BZPYZn in air 5 BZPYZn (σ) Arrhenius Fig. 5 Temperature dependence of the electrical conductivity (σ) and Arrhenius curves of electrical conductivity of BZPYZn in wet H h BZPYZn S/cm S/cm ( 4a) H h BZPYZn S/cm S/cm ( 5a) H 2 4b 5b H 2 BZPYZn Arrhenius ln(σt) = E a /(RT) + lna (1) A T

6 40 12 Zn BaZr 0.7 Pr 0.1 Y 0.2 O 3 δ 1833 R E a 4b 5b 700 BZPYZn ln(σt) 1/T [20] Arrhenius kj/mol kj/mol kj/mol kj/mol 700 ln(σt) ( ) H '' 1 i VO + O2 OO + 2h (2) 2 O O V '' O h i H 2 '' + V + H O(g) O + 2H (3) O 2 O i 2h + H (g) 2H + 2 (4) H 2 [21] BZPYZn [17] h BZPYZn L L0 dl α l = = (4) TL TL 0 0 L L 0 BZPYZn (TEC) /K (samarium doped ceria SDC)(TEC = /K) (La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3 δ LSGM)(TEC = /K) 6 BZPYZn Fig. 6 Thermal expansion coefficient curve of BZPYZn samples L 0 Length of the samples at room temperature; ΔL Under testing temperature, length of the sample relative to the added value of L 0. TEC BZPYZn TEC /K SOFC Ni TEC TEC [22] BZPYZn SOFC 3 1) BZPYZn % 97.3% 2) BZPYZn h 3) BZPYZn TEC /K TEC 4) Zn BZPY Zn BZPY SOFC [1],,,.

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