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BackgroundSolid oxide electrolysis cell (SOEC) offers a promising method for converting H2O into H2 at high temperatures ranging from 600 °C to 850 °C. Glass sealants, which are crucial materials in SOEC, fulfill most criteria for an ideal sealant when appropriate glass components at suitable stoichiometric proportions are selected. Nevertheless, they exhibit certain drawbacks, including limited stability, elevated gas leakage rates, and suboptimal thermal cycling performance during the SOEC operation.PurposeThis study aims to evaluate the performance of Al2O3 added Ba-Si-Ca sealant for SOEC.MethodsFirstly, a new Ba-Si-Ca system sealing glass (glass-P) was developed to enhance its properties, such as the coefficient of thermal expansion, glass transition, and softening temperatures, and a series of alumina additions to glass-P, intended for use as the SOEC sealant, were prepared using curtain coating. Then, the coefficients of thermal expansion of these sealants were evaluated using a thermal expansion instrument. The leak rate of the sealants, as well as the impact of different alumina additives on the material's thermal shock resistance and chemical stability, were assessed via a 1-cell stack measurement for extended SOEC operation. Finally, the elemental distribution of the specimen was observed using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (EDS).ResultsThe experimental results show that the leakage rate of the glass P-10 sealant is measured at 5.54×10-3 sccm∙cm-1, which is lower than that of glass P. After undergoing ten thermal cycles, the leakage rate of glass P-10 is found to be 2.275×10-2 sccm∙cm-1, lower than that of the others. An open circuit voltage (OCV) of approximately 1.169 V is recorded for glass P-10 after a 1 053-h test.ConclusionsThe addition of alumina to glass P significantly enhances the sealant's thermal stability and gas tightness.

BackgroundThe performance of solid oxide fuel cells (SOFCs) can be promoted by optimizing cathode materials.PurposeThis study aims to boost the electrochemical performances of cathodes for SOFCs by doping transition metal at the B-site of double perovskite.MethodsFirstly, a series of B-site doped PrBa0.8Ca0.2Co2O5+δ (PBCC) oxides as cathodes for SOFCs were prepared by sol-gel. The effects of B-site doped content and doped elements on the crystalline structure of the cathodes were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). Then, the trends of conductivity and thermal expansion coefficient with B-site doped PBCC oxides were investigated. Finally, the electrochemical performances of cathodes with different B-site doped PBCC oxides were tested to find optimal doping element type and content.ResultsTest results show that polarization is reduced and the electrochemical catalytic activity is improved when 5 mol% of Fe is doped on the B-site of the PBCC cathode. Compared to the PBCC cathode, the max power density of the full cell with a 5-mol% Fe-doped cathode increases from 988 mW∙cm-2 to 1 259 mW∙cm-2 at 700 ℃.ConclusionsThe electrochemical performances of SOFCs can be boosted by modifying the B-site of double perovskite using transition metal.

Reversible solid oxide fuel cell (RSOC) has gained widespread attention due to their potential for high efficiency in implementing multi‐energy distributed systems. When high power demand is required, RSOC can operate in the solid oxide fuel cell (SOFC) mode, directly converting the chemical energy from hydrogen or other renewable fuels into electricity. When excess electricity is available, RSOC can operate in the solid oxide electrolysis cell (SOEC) mode, producing fuels through the electrolysis of water or co‐electrolysis of water and carbon dioxide. The reversible operation of RSOC enables the direct conversion between chemical energy and electricity, offering a promising solution for clean and sustainable energy with low cost and high round‐trip efficiency. This paper introduces the research background and working principles of RSOC, provides a detailed overview of the current research status of electrolyte, fuel electrode, and oxygen electrode materials, discusses the optimization design of RSOC stacks and energy utilization strategies in the system. In addition, the future development directions of RSOC were also explored, which is of significant importance for the commercialization of RSOC. [ABSTRACT FROM AUTHOR]