Fluorination of BaZr0.1Ce0.7Y0.1Yb0.1O3 as Electrolyte Material for Proton Conducting Solid Oxide Fuel Cell

doi:10.15541/jim20240535

Abstract

Abstract: Proton-conducting solid oxide fuel cells (H⁺-SOFC) have gained great attention due to weak temperature dependence and high energy conversion efficiency. In this work, a fluorination strategy based on the BaZr_0.1Ce_0.7Y_0.1Yb_0.1O₃(BZCYYb) electrolyte was proposed to improve the proton conductivity. It was found that the conductivity (σ) of the fluorinated BZCYYbF, BaZr_0.1Ce_0.7Y_0.1Yb_0.1O_2.9F_0.1 (BZCYYbF), is 4.59×10^-3-2.14×10^-2 S/cm at 450~800 ℃ in dry H₂, higher than that of primitive BZCYYb electrolyte (σ=3.99×10^-3-1.86×10^-2 S/cm). It is found that the electrolyte fluorination significantly reduces the anode polarization resistance (R_p) for hydrogen oxidation reaction from 2.5 Ω·cm² to 1.94 Ω·cm², and the total resistance (R_tot) of the single cell with 300-μm-thick electrolyte supporting from 1.54 Ω·cm² to 1.45 Ω·cm², respectively. Therefore, the BZCYYbF single cell shows much higher maximum power density (172 mW·cm^-2) than the BZCYYb single cell (144 mW·cm^-2) at 700 ℃. This result is attributed to the fact that the electrolyte fluorination not only improves the proton conduction capacity but also enhances the rates of H₂ diffusion and adsorption/dissociation on the anode sides. In conclusion, the fluorination of BZCYYb electrolyte can significantly improve its proton conductivity and thereby contributes to superior electrochemical performance of H⁺-SOFC.

Key words: proton conducting solid oxide fuel cell (H⁺-SOFC), proton conducting electrolyte, fluorination, conductivity, electrochemical performance

CLC Number:

TQ15

JIANG Yuehong, SONG Yunfeng, ZHANG Leilei, MA Ji, SONG Zhaoyuan, LONG Wen. Fluorination of BaZr0.1Ce0.7Y0.1Yb0.1O3 as Electrolyte Material for Proton Conducting Solid Oxide Fuel Cell[J]. Journal of Inorganic Materials, DOI: 10.15541/jim20240535.

References

[1] TSVETKOV N, KIM D, JEONG I,et al. Advances in materials and interface understanding in protonic ceramic fuel cells. Advanced Materials Technologies, 2023, 8(20): 2201075.
[2] GAO Y, LIU KC, LI Q,et al. The approaches to conducting in-situ heterostructure electrodes for SOCs: a mini review. Sustainable Materials and Technologies, 2024, 41: e01107.
[3] LUO Y, ZHANG D, LIU T, et al. In situ exsolution of quaternary alloy nanoparticles for CO₂‐CO mutual conversion using reversible solid oxide cells. Advanced Functional Materials, 2024, 34(40): 2403922.
[4] ZHOU M Y, LIU Z J, CHEN M L,et al. Electrochemical performance and chemical stability of proton-conducting BaZr_0.8-_xCe_xY_0.2O₃-_δ electrolytes. Journal of the American Ceramic Society, 2022, 105(9): 5711.
[5] YANG L, WANG S, BLINN K, Liu, et al. Enhanced sulfur and coking tolerance of a mixed ion conductor for SOFCs: BaZr_0.1Ce_0.7Y_0.2-_xYb_xO₃-_δ. Science, 2009, 326(5949): 126.
[6] GUO Y, LIN Y, RAN R, et al. Zirconium doping effect on the performance of proton-conducting BaZr_yCe_0.8-_yY_0.2O₃-_δ(0.0≤y≤0.8) for fuel cell applications. Journal of Power Sources, 2009, 193(2): 400.
[7] ZHONG Z.Stability and conductivity study of the BaCe_0.9-_xZr_xY_0.1O_2.95 systems. Solid State Ionics, 2007, 178(3/4): 213.
[8] CHOI S, KUCHARCZYK C J, LIANG Y, et al. Exceptional power density and stability at intermediate temperatures in protonic ceramic fuel cells. Nature Energy, 2018, 3(3): 202.
[9] CHOI S Y, TIMOTH C, SOSSINA M H.Protonic ceramic electrochemical cells for hydrogen production and electricity generation: exceptional reversibility, stability, and demonstrated faradaic efficiency.Energy and Environmental Science, 2019, 12(1): 206.
[10] REN R, Yu X, WANG Z,et al. Fluorination inductive e□ect enables rapid bulk proton diffusion in BaCo_0.4Fe_0.4Zr_0.1Y_0.1O₃-_δ perovskite oxide for high-activity protonic ceramic fuel cell cathode. Applied Catalysis B: Environmental, 2022, 317(1): 121759.
[11] LI W, LI Y, F L, et al. Enhancing performance of proton ceramic fuel cells through fluorine-doped perovskite oxides. Rare Metals, 2025, DOI: 10.1007/s12598-024-03115-8
[12] JIANG T, LIU Y, WANG Z,et al. An improved direct current sintering technique for proton conductor - BaZr_0.1Ce_0.7Y_0.1Yb_0.1O₃-_δ: the effect of direct current on sintering process. Journal of Power Sources, 2014, 248(8): 70.
[13] ZHANG Y, XIE D, CHI B,et al. Basic properties of proton conductor BaZr_0.1Ce_0.7Y_0.1Yb_0.1O₃-_δ(BZCYYb) material. Asia-Pacific Journal of Chemical Engineering, 2019, 14(4): 58.
[14] CHEN T, JING Y H, ANDERSON L O, et al. Toward durable protonic ceramic cells: hydration-induced chemical expansion correlates with symmetry in the Y-doped BaZrO₃-BaCeO₃ solid solution. The Journal of Physical Chemistry, 2021, 125(47): 26216.
[15] LOKEN A, RICOTE S, WACHOWSKI S,et al. Thermal and chemical expansion in proton ceramic electrolytes and compatible electrodes. Crystals, 2018, 8(9): 365.
[16] STOKES S J, SAIFUL I.Defect chemistry and proton-dopant association in BaZrO₃ and BaPrO₃. Journal of Materials Chemistry, 2010, 20(6): 6258.
[17] ZHONG Z Y, SONG T, ZHAO S K,et al. High-performance BaZr_0.1Ce_0.7Y_0.1Yb_0.1O₃-_δ(BZCYYb) protonic ceramic fuel cell electrolytes by the Ba evaporation inhibition strategy. Ceramics International, 2024, 50(2): 3633.
[18] ZHU H, RICOTE S, COORS W G,et al. Interpreting equilibrium-conductivity and conductivity-relaxation measurements to establish thermodynamic and transport properties for multiple charged defeat conducting ceramics. Faraday Discussions, 2015, 182(3): 49.
[19] ZHU H Y, SANDRINE R, DUAN C C, et al. Defect chemistry and transport within dense BaZr_0.1Ce_0.7Y_0.1Yb_0.1O₃-_δ(BZCYYb) proton-conducting membranes. Journal of The Electrochemical Society, 2018, 10(2): 3633.
[20] SOMEKAWA T, TACHIKAWA Y, TACHIKAWA Y,et al. Physicochemical properties of proton conductive Ba(Zr_0.1Ce_0.7Y_0.1Yb_0.1)O₃-_δ solid electrolyte in terms of electrochemical performance of solid oxide fuel cells. International journal of hydrogen energy, 2016, 41(39): 17539.
[21] WANG J, ZHANG D, LIU T,et al. Self-assembled Fe Ru bimetallic nano catalysts for efficient and durable mutual CO-CO₂ conversion in a reversible solid oxide electrochemical cell. Science China Materials, 2024, 67(5): 1471.
[22] CHEN H N, ZHANF H C, ZHOU Y J,et al. Structure-conduction correlations in a chlorine-rich superionic lithium-argyrodite solid electrolyte: a DRT analysis. Journal of Power Sources, 2023, 583(1): 233579.
[23] YANG Q, TIAN D, LIU R,et al. Exploiting rare-earth-abundant layered perovskite cathodes of LnBa_0.5Sr_0.5Co_1.5Fe_0.5O₅+_δ (Ln= La and Nd) for SOFCs. International Journal of Hydrogen Energy, 2021, 46(7): 5630.
[24] D.L, YAN.D, JIA L,et al. A comparative study on the composite cathodes with proton conductor and oxygen ion conductor for proton-conducting solid oxide fuel cell. Electrchimica Acta, 2020, 344(4): 136.
[25] SUMI H, SHIMADA H, WAANABE K,et al. External current dependence of polarization resistances for reversible solid oxide and protonic ceramic cells with current leakage. ACS Applied Energy Materials 2023, 6(3): 1853.
[26] SHI H G, HU Y, FENG Z X,et al. Solid-state synthesis of BaCe_0.16Y_0.04Fe_0.8O₃-_δ cathode for protonic ceramic fuel cells. Asia-Pacific Journal of Chemical Engineering, 2022, 17(4): e2789 .