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Sheikh AA, Bianchi FR, Bove D, Bosio B. A review on MCFC matrix: State-of-the-art, degradation mechanisms and technological improvements. Heliyon 2024; 10:e25847. [PMID: 38384559 PMCID: PMC10878923 DOI: 10.1016/j.heliyon.2024.e25847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 01/02/2024] [Accepted: 02/03/2024] [Indexed: 02/23/2024] Open
Abstract
Molten Carbonate Fuel Cells (MCFCs) are a promising technology as sustainable power generators as well as CO2 selective concentrators for carbon capture applications. Looking at the current cell configuration, several issues, which hinders a stable long-term operation of the system, are still unsettled. According to reference studies, the ceramic matrix is one of the most critical components in view of its high impact on the cell performance since it can influence both the stability and the reaction path. Indeed, it provides the structural support and holds the molten carbonates used as electrolyte, requiring a good mechanical strength despite of a porous structure, a high specific surface area and a sufficient electrolyte wettability to avoid the electrode flooding. The matrix structure, its key-features and degradation issues are discussed starting from the state-of-the-art lithium aluminate LiAlO2 usually strengthened with Al based reinforcement agents. Since the achievable performance is strictly dependent on manufacturing, a devoted section focuses on available techniques with a view also of their environmental impacts. Considering a still insufficient performance due to the material structural and chemical instability favoured by stressful working conditions, the electric conductive ceramics are presented as alternative matrixes permitting to increase the cell performance combining oxygen and carbonate ion paths.
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Affiliation(s)
- Asrar A. Sheikh
- Department of Civil, Chemical and Environmental Engineering (DICCA), University of Genoa, Via Opera Pia 15, 16145 Genoa, Italy
| | - Fiammetta R. Bianchi
- Department of Civil, Chemical and Environmental Engineering (DICCA), University of Genoa, Via Opera Pia 15, 16145 Genoa, Italy
| | - Dario Bove
- Department of Civil, Chemical and Environmental Engineering (DICCA), University of Genoa, Via Opera Pia 15, 16145 Genoa, Italy
| | - Barbara Bosio
- Department of Civil, Chemical and Environmental Engineering (DICCA), University of Genoa, Via Opera Pia 15, 16145 Genoa, Italy
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Arshad MS, Billing C, Billing DG, Guan W. Phase-Assisted Tailored Conductivity of Doped Ceria Electrolytes to Boost SOFC Performance. ACS APPLIED MATERIALS & INTERFACES 2023; 15:39396-39407. [PMID: 37556767 PMCID: PMC10450644 DOI: 10.1021/acsami.3c08146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 07/27/2023] [Indexed: 08/11/2023]
Abstract
Efforts to lower the operating temperature of solid oxide fuel cells include producing electrolytes that are sufficiently conductive and stable below 600 °C. Doped ceria is one such electrolyte being considered. During this study, codoped ceria powders (Ce0.8Sm0.2-xMxO2-δ, M = Bi3+, Zn2+ and x = 0, 0.05, 0.1, 0.15, 0.2) were prepared via coprecipitation by the addition of sodium carbonate and annealed at 800 and 1200 °C, respectively. Poor solubility of the codopants in the ceria was observed for samples annealed at 800 °C, resulting in a mixed-phase product including stable phases of the oxides of these codopants. A second-stage partial incorporation of these codopants into the ceria lattice was observed when the annealing temperature was increased to 1200 °C, with both codopants forming cubic-type phases of their respective oxides. Materials were characterized using X-ray diffraction (XRD), Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR), as well as scanning electron microscopy (SEM) for structural and morphological investigations. The oxide ion conductivity was evaluated using electrochemical impedance spectroscopy between 550 and 750 °C. Fuel cell performance tests of selected samples (annealed at 1200 °C) showed remarkable improvement in peak power densities when the test temperature was increased from 500 to 600 °C (∼720 mW/cm2 for Ce0.8Sm0.15Bi0.05O2-δ and ∼1230 mW/cm2 for Ce0.8Sm0.15Zn0.05O2-δ), indicating possible contribution from the distinct cubic-type oxide phases of the codopants in performance enhancement.
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Affiliation(s)
- Muhammad S. Arshad
- Molecular
Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag X3, Johannesburg 2050, South Africa
- Department
of Chemical Sciences, University of Johannesburg, Doornfontein, Johannesburg 2028, South Africa
- Ningbo
Institute of Material Technology and Engineering, Chinese Academy
of Sciences, Ningbo 315201, China
| | - Caren Billing
- Molecular
Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag X3, Johannesburg 2050, South Africa
| | - David G. Billing
- Molecular
Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag X3, Johannesburg 2050, South Africa
| | - Wanbing Guan
- Ningbo
Institute of Material Technology and Engineering, Chinese Academy
of Sciences, Ningbo 315201, China
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Wang X, Wang J, Sun Y, Li K, Shang T, Wan Y. Recent advances and perspectives of CeO 2-based catalysts: Electronic properties and applications for energy storage and conversion. Front Chem 2022; 10:1089708. [PMID: 36569964 PMCID: PMC9772620 DOI: 10.3389/fchem.2022.1089708] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 11/28/2022] [Indexed: 12/13/2022] Open
Abstract
Cerium dioxide (CeO2, ceria) has long been regarded as one of the key materials in modern catalysis, both as a support and as a catalyst itself. Apart from its well-established use (three-way catalysts and diesel engines), CeO2 has been widely used as a cocatalyst/catalyst in energy conversion and storage applications. The importance stems from the oxygen storage capacity of ceria, which allows it to release oxygen under reducing conditions and to store oxygen by filling oxygen vacancies under oxidizing conditions. However, the nature of the Ce active site remains not well understood because the degree of participation of f electrons in catalytic reactions is not clear in the case of the heavy dependence of catalysis theory on localized d orbitals at the Fermi energy E F . This review focuses on the catalytic applications in energy conversion and storage of CeO2-based nanostructures and discusses the mechanisms for several typical catalytic reactions from the perspectives of electronic properties of CeO2-based nanostructures. Defect engineering is also summarized to better understand the relationship between catalytic performance and electronic properties. Finally, the challenges and prospects of designing high efficiency CeO2-based catalysts in energy storage and conversion have been emphasized.
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Characteristics of Li2CO3 as sintering aid for Ce0.8Sm0.2O2−δ electrolyte in solid oxide fuel cells. KOREAN J CHEM ENG 2022. [DOI: 10.1007/s11814-022-1112-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Synthesis and Characterizations of Barium Zirconate–Alkali Carbonate Composite Electrolytes for Intermediate Temperature Fuel Cells. JOURNAL OF COMPOSITES SCIENCE 2021. [DOI: 10.3390/jcs5070183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Composite ionic conductors for intermediate temperature fuel cells (ITFC) were produced by a combination of yttrium-substituted barium zirconate (BaZr0.9Y0.1 O2.95, BZY) and eutectic compositions of alkali carbonates (Li2CO3, Na2CO3, and K2CO3, abbreviated L, N, K). These materials were characterized by X-ray diffraction, scanning electron microscopy, and impedance spectroscopy. The combination of BZY with alkali metal carbonate promotes the densification and enhances the ionic conductivity, which reaches 87 mS·cm−1 at 400 °C for the BZY–LNK40 composite. In addition, the increase of the conductivity as a function of hydrogen partial pressure suggests that protons are the main charge carriers. The results are interpreted in terms of the transfer of protons from the ceramic component to the carbonate phase in the interfacial region.
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Shaping of ceria-based single solid oxide cells combining tape-casting, screen-printing and infiltration. Ann Ital Chir 2020. [DOI: 10.1016/j.jeurceramsoc.2020.07.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Nie X, Chen Y, Mushtaq N, Rauf S, Wang B, Dong W, Wang X, Wang H, Zhu B. The sintering temperature effect on electrochemical properties of Ce 0.8Sm 0.05Ca 0.15O 2-δ (SCDC)-La 0.6Sr 0.4Co 0.2Fe 0.8O 3-δ (LSCF) heterostructure pellet. NANOSCALE RESEARCH LETTERS 2019; 14:162. [PMID: 31089827 PMCID: PMC6517467 DOI: 10.1186/s11671-019-2979-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 04/10/2019] [Indexed: 05/06/2023]
Abstract
Recently, semiconductor-ionic materials (SIMs) have emerged as new functional materials, which possessed high ionic conductivity with successful applications as the electrolyte in advanced low-temperature solid oxide fuel cells (LT-SOFCs). In order to reveal the ion-conducting mechanism in SIM, a typical SIM pellet consisted of semiconductor La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) and ionic conductor Sm and Ca Co-doped ceria Ce0.8Sm0.05Ca0.15O2-δ (SCDC) are suffered from sintering at different temperatures. It has been found that the performance of LSCF-SCDC electrolyte fuel cell decreases with the sintering temperature, the cell assembled from LSCF-SCDC pellet sintered at 600 °C exhibits a peak power density (Pmax) of 543 mW/cm2 at 550 °C and also excellent performance of 312 mW/cm2 even at LT (500 °C). On the contrary, devices based on 1000 °C pellet presented a poor Pmax of 106 mW/cm2. The performance difference may result from the diverse ionic conductivity of SIM pellet through different temperatures sintering. The high-temperature sintering could severely destroy the interface between SCDC and LSCF, which provide fast transport pathways for oxygen ions conduction. Such phenomenon provides direct and strong evidence for the interfacial conduction in LSCF-SCDC SIMs.
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Affiliation(s)
- Xiyu Nie
- Key Laboratory of Ferro and Piezoelectric Materials and Devices, Faculty of Physics and Electronic Science, Hubei University, Youyi Road 368, Wuhan, 430062 Hubei People’s Republic of China
| | - Ying Chen
- Key Laboratory of Ferro and Piezoelectric Materials and Devices, Faculty of Physics and Electronic Science, Hubei University, Youyi Road 368, Wuhan, 430062 Hubei People’s Republic of China
| | - Naveed Mushtaq
- Key Laboratory of Ferro and Piezoelectric Materials and Devices, Faculty of Physics and Electronic Science, Hubei University, Youyi Road 368, Wuhan, 430062 Hubei People’s Republic of China
| | - Sajid Rauf
- Key Laboratory of Ferro and Piezoelectric Materials and Devices, Faculty of Physics and Electronic Science, Hubei University, Youyi Road 368, Wuhan, 430062 Hubei People’s Republic of China
| | - Baoyuan Wang
- Key Laboratory of Ferro and Piezoelectric Materials and Devices, Faculty of Physics and Electronic Science, Hubei University, Youyi Road 368, Wuhan, 430062 Hubei People’s Republic of China
| | - Wenjing Dong
- Key Laboratory of Ferro and Piezoelectric Materials and Devices, Faculty of Physics and Electronic Science, Hubei University, Youyi Road 368, Wuhan, 430062 Hubei People’s Republic of China
| | - Xunying Wang
- Key Laboratory of Ferro and Piezoelectric Materials and Devices, Faculty of Physics and Electronic Science, Hubei University, Youyi Road 368, Wuhan, 430062 Hubei People’s Republic of China
| | - Hao Wang
- Key Laboratory of Ferro and Piezoelectric Materials and Devices, Faculty of Physics and Electronic Science, Hubei University, Youyi Road 368, Wuhan, 430062 Hubei People’s Republic of China
| | - Bin Zhu
- Key Laboratory of Ferro and Piezoelectric Materials and Devices, Faculty of Physics and Electronic Science, Hubei University, Youyi Road 368, Wuhan, 430062 Hubei People’s Republic of China
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