Al³⁺ doped CeO₂ for proton conducting fuel cells

Abstract

Developing high ionic conducting electrolytes is crucial for applying proton-conducting fuel cell (PCFCs) practically. The current study investigates the effect of alumina on the structural, morphological, electrical, and electrochemical properties of CeO₂. Lattice oxygen vacancies are induced in CeO₂ by a general doping concept that enables fast ionic conduction at low-temperature ranges (300–500°C) for PCFCs. Rietveld refinement of the X-ray diffraction (XRD) patterns established the pure cubic fluorite structure of Al-doped CeO₂ (ADC) samples and confirmed Al ions’ fruitful integration in the CeO₂ lattice. The electronic structure of the alumina-doped ceria of the materials (10ADC, 20ADC, and 30ADC) has been investigated. As a result, it was found that the best composition of 30ADC-based electrolytes induced maximum lattice oxygen vacancies. The corresponding PCFC exhibited a maximum power output of 923 mW/cm² at 500°C. Moreover, the investigation proves the proton-conducting ability of alumina-doped ceria-based fuel cells by using an oxide ion-blocking layer.

Keywords

proton ceramic fuel cells / oxygen vacancies / higher fuel cell performance / doping / fast ions transportation

References

[1] Liang FY, Yang JR, Wang HQ, Wu JW. Fabrication of Gd₂O₃-doped CeO₂ thin films through DC reactive sputtering and their application in solid oxide fuel cells. Int. J. Miner. Metall. Mater., 2023, 30(6): 1190,

[2] Yang X, Du ZH, Zhang Q, et al.. Effects of operating conditions on the performance degradation and anode microstructure evolution of anode-supported solid oxide fuel cells. Int. J. Miner. Metall. Mater., 2023, 30(6): 1181,

[3] Duan CC, Tong JH, Shang M, et al.. Readily processed protonic ceramic fuel cells with high performance at low temperatures. Science, 2015, 349(6254): 1321,

[4] H.P. Ding, W. Wu, C. Jiang, et al., Self-sustainable protonic ceramic electrochemical cells using a triple conducting electrode for hydrogen and power production, Nat. Commun., 11(2020), No. 1, art. No. 1907.

[5] Zhang X, Li YK, Zhao W, Guo JX, Yin PF, Ling T. Technical factors affecting the performance of anion exchange membrane water electrolyzer. Int. J. Miner. Metall. Mater., 2023, 30(11): 2259,

[6] Han S, Wei T, Wang SJ, et al.. Recent progresses in the development of tubular segmented-in-series solid oxide fuel cells: Experimental and numerical study. Int. J. Miner. Metall. Mater., 2024, 31(3): 427,

[7] Norby T, Magrasó A. On the development of proton ceramic fuel cells based on Ca-doped LaNbO₄ as electrolyte. J. Power Sources, 2015, 282: 28,

[8] Zhou Y, Guan XF, Zhou H, et al.. Strongly correlated perovskite fuel cells. Nature, 2016, 534(7606): 231,

[9] Xing Y M, Wu Y, Li LY, et al.. Proton shuttles in CeO₂/CeO_2−δ core–shell structure. ACS Energy Lett., 2019, 4(11): 2601,

[10] Liu YY, Fan LD, Cai YX, Zhang W, Wang BY, Zhu B. Superionic conductivity of Sm³⁺, Pr³⁺, and Nd³⁺ triple-doped ceria through bulk and surface two-step doping approach. ACS Appl. Mater. Interfaces, 2017, 9(28): 23614,

[11] Choi S, Kucharczyk CJ, Liang YG, et al.. Exceptional power density and stability at intermediate temperatures in protonic ceramic fuel cells. Nat. Energy, 2018, 3: 202,

[12] Li CM, Zeng YW, Wang ZT, Ye ZP, Zhang Y. Processing temperature tuned interfacial microstructure and protonic and oxide ionic conductivities of well-sintered Sm_0.2Ce_0.8O_1.9–Na₂CO₃ nanocomposite electrolytes for intermediate temperature solid oxide fuel cells. J. Power Sources, 2017, 360: 114,

[13] B.Y. Wang, B. Zhu, S.N. Yun, et al., Fast ionic conduction in semiconductor CeO_2−δ electrolyte fuel cells, NPG Asia Mater., 11(2019), art. No. 51.

[14] Chen G, Sun WK, Luo YD, et al.. Advanced fuel cell based on new nanocrystalline structure Gd_0.1Ce_0.9O₂ electrolyte. ACS Appl. Mater. Interfaces, 2019, 11(11): 10642,

[15] Shah MAKY, Lu YZ, Mushtaq N, et al.. Designing Gadolinium-doped ceria electrolyte for low temperature electrochemical energy conversion. Int. J. Hydrogen Energy, 2023, 48(37): 14000,

[16] Chen G, Sun WK, Luo YD, et al.. Investigation of layered Ni_0.8Co_0.15Al_0.05LiO₂ in electrode for low-temperature solid oxide fuel cells. Int. J. Hydrogen Energy, 2018, 43(1): 417,

[17] Liu JJ, Yang F, Jiang Z, et al.. Enhanced ionic conductivity and durability of novel solid oxide fuel cells by constructing a heterojunction based on transition and rare earth metal Co-doped ceria. ACS Appl. Energy Mater., 2021, 4(12): 13492,

[18] Kang CY, Kusaba H, Yahiro H, Sasaki K, Teraoka Y. Preparation, characterization and electrical property of Mn-doped ceria-based oxides. Solid State Ionics, 2006, 177(19–25): 1799,

[19] C. Alvarez-Galvan, J.L. Martínez, M. Capel-Sanchez, L. Pascual, and J.A. Alonso, Magnetic properties of efficient catalysts based on La-doped ceria-supported nickel nanoparticles for rWGS reaction. influence of Ni loading, Adv. Sustainable Syst., 5(2021), No. 11, art. No. 2100029.

[20] Sartoretti E, Novara C, Chiodoni A, et al.. Nanostructured ceria-based catalysts doped with La and Nd: How acid-base sites and redox properties determine the oxidation mechanisms. Catal. Today, 2022, 390: 117,

[21] Knözinger H, Ratnasamy P. Catalytic aluminas: Surface models and characterization of surface sites. Catal. Rev., 1978, 17(1): 31,

[22] Sánchez-Valente J, Bokhimi X, Hernández F. Physico-chemical and catalytic properties of sol–gel aluminas aged under hydrothermal conditions. Langmuir, 2003, 19(9): 3583,

[23] Jirátová K, Beránek L. Properties of modified aluminas. Appl. Catal., 1982, 2(3): 125,

[24] Asada T, Kayama T, Kusaba H, Einaga H, Teraoka Y. Preparation of alumina-supported LaFeO₃ catalysts and their catalytic activity for propane combustion. Catal. Today, 2008, 139(1–2): 37,

[25] Shah MAK Y, Lu YZ, Mushtaq N, Yousaf M, Zhu B. Doped ceria electrolyte rich in oxygen vacancies for boosting the fuel cell performance of LT-CFCs. Int. J. Hydrogen Energy, 2023, 48(33): 12474,

[26] Anirban S, Paul T, Das PT, Nath TK, Dutta A. Microstructure and electrical relaxation studies of chemically derived Gd–Nd co-doped nanocrystalline ceria electrolytes. Solid State Ionics, 2015, 270: 73,

[27] Kahlaoui M, Inoubli A, Chefi S, et al.. Structural, chemical, and electrochemical properties of co-doped fluorite oxides Ce_0.8La_0.2−xTl_xO_2−δ as electrolyte materials for solid oxide fuel cells. Int. J. Hydrogen Energy, 2016, 41(8): 4751,

[28] Wang ZT, Zeng YW, Li CM, Ye ZP, Cao LL, Zhang Y. Structures and electrical conductivities of Gd³⁺ and Fe³⁺ co-doped cerium oxide electrolytes sintered at low temperature for ILT-SOFCs. Ceram. Int., 2018, 44(9): 10328,

[29] Wu ZL, Li MJ, Howe J, Meyer HM III, Overbury SH. Probing defect sites on CeO₂ nanocrystals with well-defined surface planes by Raman spectroscopy and O₂ adsorption. Langmuir, 2010, 26(21): 16595,

[30] Anirban S, Dutta A. Revisiting ionic conductivity of rare earth doped ceria: Dependency on different factors. Int. J. Hydrogen Energy, 2020, 45(46): 25139,

[31] Schmitt R, Nenning A, Kraynis O, et al.. A review of defect structure and chemistry in ceria and its solid solutions. Chem. Soc. Rev., 2020, 49(2): 554,

[32] Wu YC, Lin CC. The microstructures and property analysis of aliovalent cations (Sm³⁺, Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺) co-doped ceria-base electrolytes after an aging treatment. Int. J. Hydrogen Energy, 2014, 39(15): 7988,

[33] Kosacki I, Suzuki T, Anderson HU, Colomban P. Raman scattering and lattice defects in nanocrystalline CeO₂ thin films. Solid State Ionics, 2002, 149(1–2): 99,

[34] Mineshige A, Taji T, Muroi Y, et al.. Oxygen chemical potential variation in ceria-based solid oxide fuel cells determined by Raman spectroscopy. Solid State Ionics, 2000, 135(1–4): 481,

[35] Ansari SA, Khan MM, Ansari MO, Kalathil S, Lee J, Cho MH. Band gap engineering of CeO₂ nanostructure using an electrochemically active biofilm for visible light applications. RSC Adv., 2014, 4(32): 16782,

[36] X.Y. Zhang, J.Q. Qin, Y.N. Xue, et al., Effect of aspect ratio and surface defects on the photocatalytic activity of ZnO nanorods, Sci. Rep., 4(2014), art. No. 4596.

[37] Sonsupap S, Kidkhunthod P, Chanlek N, Pinitsoontorn S, Maensiri S. Fabrication, structure, and magnetic properties of electrospun Ce_0.96Fe_0.04O₂ nanofibers. Appl. Surf. Sci., 2016, 380: 16,

[38] Caglar M, Yakuphanoglu F. Structural and optical properties of copper doped ZnO films derived by sol–gel. Appl. Surf. Sci., 2012, 258(7): 3039,

[39] Shaheen N, Chen Z, Alomar M, et al.. Enabling fast ionic transport in CeO₂–La_1−2xBa_xBi_xFeO₃ nanocomposite electrolyte for low temperature solid oxide fuel cell application. RSC Adv., 2023, 13(30): 20663,

[40] M. Yousaf, Y.Z. Lu, E.Y. Hu, et al., Interfacial disordering and heterojunction enabling fast proton conduction, Small Methods, 7(2023), No. 9, art. No. 2300450.

[41] Zheng JM, Zhu H, Li WQ, et al.. Numerical study on the electron-blocking effect and optimized operation parameters of ceria-SOFCs with the pure Sm doping CeO₂ electrolyte. Int. J. Hydrogen Energy, 2021, 46(24): 13318,

[42] Mori T, Drennan J, Lee JH, Li JG, Ikegami T. Oxide ionic conductivity and microstructures of Sm- or La-doped CeO₂-based systems. Solid State Ionics, 2002, 154–155: 461,

[43] Wang SF, Liao YL, Hsu YF, Jasinski P. Effects of LiNi_0.8Co_0.15Al_0.05O₂ electrodes on the conduction mechanism of Sm_0.2Ce_0.8O_2−δ electrolyte and performance of low-temperature solid oxide fuel cells. J. Power Sources, 2022, 546: 231995,

[44] Peng XZ, Tian YF, Liu Y, et al.. A double perovskite decorated carbon-tolerant redox electrode for symmetrical SOFC. Int. J. Hydrogen Energy, 2020, 45(28): 14461,

[45] Zhou XM, Zhou F. Application of La_0.3Sr_0.7Fe_0.7Ti_0.3 O_3−δ/GDC electrolyte in LT-SOFC. Int. J. Hydrogen Energy, 2021, 46(15): 9988,

[46] Meng YJ, Zhang W, He ZL, et al.. Partially reduced Ni_0.8Co_0.15Al_0.05LiO_2−δ for low-temperature SOFC cathode. Int. J. Hydrogen Energy, 2021, 46(15): 9874,

[47] Shi N, Su F, Huan DM, et al.. Performance and DRT analysis of P-SOFCs fabricated using new phase inversion combined tape casting technology. J. Mater. Chem. A, 2017, 5(37): 19664,

[48] Oz A, Singh K, Gelman D, Thangadurai V, Tsur Y. Understanding of oxygen reduction reaction on perovskite-type Ba_0.5Sr_0.5Fe_0.91Al_0.09O_3−γ and Ba_0.5Sr_0.5Fe_0.8Cu_0.2O_3−δ using AC impedance spectroscopy genetic programming. J. Phys. Chem. C, 2018, 122(27): 15097,

[49] Garbayo I, Pla D, Morata A, Fonseca L, Sabaté N, Tarancón A. Full ceramic micro solid oxide fuel cells: Towards more reliable MEMS power generators operating at high temperatures. Energy Environ. Sci., 2014, 7(11): 3617,

[50] Mahato N, Banerjee A, Gupta A, Omar S, Balani K. Progress in material selection for solid oxide fuel cell technology: A review. Prog. Mater. Sci., 2015, 72: 141,

[51] Prabhakaran K, Beigh MO, Lakra J, Gokhale NM, Sharma SC. Characteristics of 8mol% yttria stabilized zirconia powder prepared by spray drying process. J. Mater. Process. Technol., 2007, 189(1–3): 178,

[52] Fabbri E, D’Epifanio A, Bartolomeo ED, Licoccia S, Traversa E. Tailoring the chemical stability of Ba(Ce_0.8−xZr_x) Y_0.2O_3−δ protonic conductors for intermediate temperature solid oxide fuel cells (IT-SOFCs). Solid State Ionics, 2008, 179(15–16): 558,

[53] Zuo C, Zha S, Liu M, Hatano M, Uchiyama M. Ba(Zr_0.1Ce_0.7Y_0.2)O_3−δ as an electrolyte for low-temperature solid-oxide fuel cells. Adv. Mater., 2006, 18(24): 3318,

[54] Shah MAKY, Lu YZ, Mushtaq N, et al.. Perovskite Al–Sr-TiO₃ semiconductor electrolyte with superionic conduction in ceramic fuel cells. Sustain. Energy Fuels, 2022, 6(16): 3794,

[55] F.Z. Wang, E.Y. Hu, H. Wu, et al., Surface-engineered homo-structure for enhancing proton transport, Small Meth., 6(2022), No. 1, art. No. 2100901.

[56] Medvedev DA, Lyagaeva JG, Gorbova EV, Demin AK, Tsiakaras P. Advanced materials for SOFC application: Strategies for the development of highly conductive and stable solid oxide proton electrolytes. Prog. Mater. Sci., 2016, 75: 38,