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This study presents a two-dimensional model for planar anode supported cells in a solid oxide fuel cells (SOFCs). The model is implemented with planar 6 cm × 6 cm anode supported cells (with an active area of 5 cm × 5 cm). The performance characteristics within each cell of the SOFC (cathode, anode, and electrolyte layer) are determined via the numerical simulation method. This method is based on the fundamental conservation laws of continuity, momentum, energy, and mass. The effects of the cathode, anode, and electrolyte layer thickness are investigated at different temperatures. The results show the behavior of the potential, temperature field, and current distributions in the cell when certain parameters (anode thickness, cathode thickness, electrolyte thickness, and temperature in the channels) are varied. The effects of varying the fuel inlet and air inlet conditions are also presented and discussed.

In this study, a planar solid oxide fuel cells (SOFCs) apparatus with a 6 cm × 6 cm anode supported single cell based on a modified button cell was designed for operation in both regular cell and button cell configurations. The apparatus was assembled with a regular cell with an active area of 5 cm × 5 cm and with a button cell with an active area of 2.54 cm2. They consist of fuel and oxidant chambers that allow heat conversion and thus increase the temperatures of the fuel inlet and oxidant inlet streams. The chambers reduced the cooling effect, thereby improved the cell performance. In addition, a wire–in–tube–type heat exchanger was designed and fabricated. This device was installed in front of the fuel inlet of the SOFC apparatus to improve heat transfer to better increase the temperature of the fuel inlet stream. Results indicate that the fuel outlet temperature of the system with heat exchanger is much higher than that of the system without heat exchanger. Thus, the performance of system with heat exchanger is largely improved. This improvement means that the wire–in–tube type heat exchanger is proved to be effectively increases the hydrogen inlet temperature by enhancing heat transfer.

Membrane electrode assemblies (MEAs) using commercial PbO 2 powder as the anode catalyst to generate ozone via water electrolysis were traditionally adopted. We found that commercial MEAs evinced the typical degradation phenomenon after a current interruption and restart during operation, where the performance degraded and partially recovered after the resumption of current. In this study, homemade MEAs using PbO 2 powder and additives were developed, which ameliorated the degradation phenomenon. SEM and XRD analysis were used to compare the anode structure of the homemade to commercial MEAs after short–and long–term operation post–resumption of current after an interruption.

The development of suitable sealants for high-temperature solid oxide fuel cells (SOFC) is a major challenge, as such sealants must withstand harsh conditions. They must be inert at the high temperatures used in SOFC operation (i.e., resistant to environments composed of oxidative and reducing gases), as well as thermo-chemically and thermo-mechanically compatible with the materials with which they are in contact. This paper presents a post-experimental analysis of variously sealants—mica paper, flexible mica paper, and thermiculite 866—used in high-temperature SOFC operation. The sealants are exposed to air or hydrogen at 600 °C–1000 °C for 100 h. The goal of this work is to investigate the thermal expansion properties (thickness expansion, coefficients of thermal expansion CTE and porosity), mechanical stability, and leakage during midterm operation. After the sealants fired at 1000 °C, their relative thicknesses increased to around 0.98, 1.01, and 0.568 mm, respectively. The coefficients of thermal expansion CTEs (600–1000 °C) for mica paper and flexible mica paper were calculated to be from 8.0 × 10−4 K−1 to 10.0 × 10−4 K−1, the CTEs of thermiculite 866 were around 1.0 × 10−4 K−1. The relative porosity of thermiculite 866, as determined through the density method, changed from 15.4% to 28.7% for temperatures from 600 °C to 1000 °C, respectively. Scanning electron microscopy is used to investigate the structure of thermiculite 866. It is tested for leakage using hydrogen from 500 to 3000 cc min−1 at 25 °C and 800 °C. The leakage rates at 3000 cc min−1 are 4.06% and 8.4% at 25 °C and 800 °C, respectively, showing that thermiculite 866 is a suitable sealant for SOFC applications.

This study reports the manufacturing of its core device–hydrogen electrode supported cell of reversible solid oxide fuel cell (RSOFC) with use of different oxygen electrode (La 0.8 Sr 0.2 MnO 3−δ = LSM, La 0.8 Sr 0.2 MnO 3 /yttria stabilized zirconia = LSM/YSZ) and its operation under solid oxide fuel cell (SOFC) and solid oxide electrolyzer cell (SOEC) mode. In order to lower difficulties during cell assembly, acceptable curvature of hydrogen electrode supported cell is accomplished with improvement of manufacturing process. Also reported are the resulting performances, both in SOEC and SOFC modes, as a function of its operating parameters such as temperature. We found that the RSOFC performance improved with increasing temperature for all oxygen electrodes–LSM, LSM + YSZ. SOFC performance with oxygen electrode–LSM is a better option while SOFC/SOEC recycling with oxygen electrode-LSM/YSZ is more durable. Identical material composition and no obvious weak connection between oxygen electrode-LSM/YSZ and electrolyte after SOFC/SOEC cycling tests are the main reasons leading to minor performance drops compared to that with electrode – LSM.

Experiments were carried out to investigate the pressure drop and heat transfer behaviors of a microchannel condenser. The effects of gravity on the condensation of steam in the microchannels were investigated for both horizontal and vertical cases. For the experimental results, the pressure drop of vertical microchannels in the condenser is lower than for horizontal microchannels. In the case of the horizontal microchannel, as the mass flow rate of steam increases from 0.01 g&middot, s&minus, 1 to 0.06 g&middot, 1, the pressure drop increases from 1.5 kPa to 50 kPa, respectively. While the mass flow rate of steam in the vertical microchannel case increases from 0.01 g&middot, 1, the pressure drop increases from 2.0 kPa to 44 kPa, respectively. This clearly indicates that the gravitational acceleration affects the pressure drop. The pressure drop of the vertical microchannel is lower than that obtained from the horizontal microchannel. In addition, the capacity of the condenser is the same in both cases. This leads to the performance index obtained from the vertical microchannel condenser being higher than that obtained from the horizontal microchannel condenser. These results are important contributions to the research on the condensation of steam in microchannels.

Cold Thermal Energy Storage (CTES) is a technology with a high potential for different cooling applications. Many previous works have investigated energy efficiency of different cold units by applying CTES systems using phase change materials (PCMs). Phase change materials (PCMs) are generally regarded as a promising material for storing thermal energy. This work presents an experimental study on phase change materials for cold storage application. The experimental process of phase-change materials is based on the following chemicals: water, propylene glycol (C3H8O2), glycerin (C3H8O3), parrafin oil (white oil LP-70), and sodium polyacrylate (C3H3NaO2)n. The temperature changes over time as ice charging and discharging the phase-change materials are investigated. At the same time, the work try to analyze the physical and chemical properties of the aforementioned phase-change materials. The results indicate that the discharging process of paraffin and glycol is rapid. As for water and sodium polyacrylate, the discharging time is slower than that of paraffin and glycol. And finally, for glycerin, the loading time is slowest compared to other chemicals, the discharging time is also slowest compared to the other four chemicals. This indicates that the latent heat of glycerin has high value, long melting time and deep ice storage temperature. This is a suitable material for use in cold storage systems as a phase change material.

Anode-supported cells are prepared by a sequence of hot pressing and co-sintering processes for solid oxide fuel cell (SOFC) applications. Commercially available porous anode tape (NiO/YSZ = 50 wt %/50 wt %), anode tape (NiO/YSZ = 30 wt %/70 wt %), and YSZ are used as the anode substrate, anode functional layer, and electrolyte layer, respectively. After hot pressing, the stacked layers are then sintered at different temperatures (1250 °C, 1350 °C, 1400 °C and 1450 °C) for 5 h in air. Different compressive loads are applied during the sintering process. An (La,Sr)MnO3 (LSM) paste is coated on the post-sintered anode-supported electrolyte surface as the cathode, and sintered at different temperatures (1100 °C, 1150 °C, 1200 °C and 1250 °C) for 2 h in air to generate anode-supported cells with dimensions of 60 × 60 mm2 (active reaction area of 50 × 50 mm2). SEM is used to investigate the anode structure of the anode-supported cells. In addition, confocal laser scanning microscopy is used to investigate the roughness of the cathode surfaces. At sintering temperatures of 1400 °C and 1450 °C, there is significant grain growth in the anode. Furthermore, the surface of the cathode is smoother at a firing temperature of 1200 °C. It is also found that the optimal compressive load of 1742 Pa led to a flatness of 168 µm/6 cm and a deformation of 0.72%. The open circuit voltage and power density of the anode-supported cell at 750 °C were 1.0 V and 178 mW·cm−2, respectively.