scholarly journals Performance Assessment of Single Electrode-Supported Solid Oxide Cells Operating in the Steam Electrolysis Mode

2011 ◽  
Author(s):  
X. Zhang ◽  
J. E. O’Brien ◽  
R. C. O’Brien ◽  
N. Petigny
Keyword(s):  
Fuel Cell ◽  
Single Cells ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Accelerated Degradation ◽  
Degradation Rates ◽  
Electrolysis Cells ◽  
Cell Test ◽  
Electrolysis Mode

An experimental study has been conducted to assess the performance of electrode-supported solid-oxide cells operating in the steam electrolysis mode for hydrogen production. Results presented in this paper were obtained from single cells, with an active area of 16 cm2 per cell. The electrolysis cells are electrode-supported, with yttria-stabilized zirconia (YSZ) electrolytes (∼10 μm thick), nickel-YSZ steam/hydrogen electrodes (∼1400 μm thick), and modified LSM or LSCF air-side electrodes (∼90 μm thick). The purpose of the present study is to document and compare the performance and degradation rates of these cells in the fuel cell mode and in the electrolysis mode under various operating conditions. Initial performance was documented through a series of voltage-current (VI) sweeps and AC impedance spectroscopy measurements. Degradation was determined through long-term testing, first in the fuel cell mode, then in the electrolysis mode. Results generally indicate accelerated degradation rates in the electrolysis mode compared to the fuel cell mode, possibly due to electrode delamination. The paper also includes details of an improved single-cell test apparatus developed specifically for these experiments.

Analysis of Long-Term and Thermal Cycling Tests for a Commercial Solid Oxide Fuel Cell

2017 ◽  
Vol 14 (4) ◽  
Author(s):  
Dustin Lee ◽  
Jing-Kai Lin ◽  
Chun-Huang Tsai ◽  
Szu-Han Wu ◽  
Yung-Neng Cheng ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Thermal Cycling ◽  
Solid Oxide Fuel Cell ◽  
Coefficient Of Thermal Expansion ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Flow Rates ◽  
Degradation Rates ◽  
Two Stages

The effects of isothermally long-term and thermal cycling tests on the performance of an ASC type commercial solid oxide fuel cell (SOFC) have been investigated. For the long-term test, the cells were tested over 5000 h in two stages, the first 3000 h and the followed 2000 h, under the different flow rates of hydrogen and air. Regarding the thermal cycling test, 60 cycles in total were also divided into two sections, the temperature ranges of 700 °C to 250 °C and 700 °C to 50 °C were applied for the every single cycle of first 30 cycles and the later 30 cycles, respectively. The results of long-term test show that the average degradation rates for the cell in the first 3000 h and the followed 2000 h under different flow rates of fuel and air are 1.16 and 2.64%/kh, respectively. However, there is only a degradation of 6.6% in voltage for the cell after 60 thermal cycling tests. In addition, it is found that many pores formed in the anode of the cell which caused by the agglomeration of Ni after long-term test. In contrast, the vertical cracks penetrating through the cathode of the cell and the in-plane cracks between the cathode and barrier layer of the cell formed due to the coefficient of thermal expansion (CTE) mismatch after 60 thermal cycling tests.

Electrochemical Performance of Ni-YSZ, Ni/Ru-GDC, LSM-YSZ, LSCF and LSF Electrodes for Solid Oxide Electrolysis Cells

2010 ◽  
Author(s):  
P. Kim-Lohsoontorn ◽  
H.-B. Yim ◽  
J.-M. Bae
Keyword(s):  
Electrochemical Performance ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Hydrogen Electrode ◽  
Anodic Reaction ◽  
Oxygen Electrodes ◽  
Electrolysis Cells ◽  
Solid Oxide Electrolysis ◽  
Solid Oxide Electrolysis Cells ◽  
Electrolysis Mode

The electrochemical performance of solid oxide electrolysis cells (SOECs) having nickel – yttria stabilized zirconia (Ni-YSZ) hydrogen electrode and a composite lanthanum strontium manganite – YSZ (La0.8Sr0.2MnO3−δ – YSZ) oxygen electrodes has been studied over a range of operating conditions temperature (700 to 900°C). Increasing temperature significantly increased electrochemical performance and hydrogen generation efficiency. Durability studies of the cell in electrolysis mode were made over 200 h periods (0.1 A/cm2, 800°C, and H2O/H2 = 70/30). The cell significantly degraded over the time (2.5 mV/h). Overpotentials of various SOEC electrodes were evaluated. Ni-YSZ as a hydrogen electrode exhibited higher activity in SOFC mode than SOEC mode while Ni/Ru-GDC presented symmetrical behavior between fuel cell and electrolysis mode and gave lower losses when compared to the Ni-YSZ electrode. All the oxygen electrodes gave higher activity for the cathodic reaction than the anodic reaction. Among the oxygen electrodes in this study, LSM-YSZ exhibited nearest to symmetrical behavior between cathodic and anodic reaction. Durability studies of the electrodes in electrolysis mode were made over 20–70 h periods. Performance degradations of the oxygen electrodes were observed (3.4, 12.6 and 17.6 mV/h for LSM-YSZ, LSCF and LSF, respectively). The Ni-YSZ hydrogen electrode exhibited rather stable performance while the performance of Ni/Ru-GDC decreased (3.4 mV/h) over the time. This was likely a result of the reduction of ceria component at high operating voltage.

scholarly journals High Temperature Water Electrolysis Using Metal Supported Solid Oxide Electrolyser Cells (SOEC)

2010 ◽  
Vol 72 ◽  
pp. 135-143 ◽  
Author(s):  
Günter Schiller ◽  
Asif Ansar ◽  
Olaf Patz
Keyword(s):  
High Temperature ◽  
Fuel Cell ◽  
Current Density ◽  
Degradation Rate ◽  
Cell Voltage ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Metallic Interconnect ◽  
A Current

Metal supported cells as developed at DLR for use as solid oxide fuel cells by applying plasma deposition technologies were investigated in operation of high temperature steam electrolysis. The cells consisted of a porous ferritic steel support, a diffusion barrier layer, a Ni/YSZ fuel electrode, a YSZ electrolyte and a LSCF oxygen electrode. During fuel cell and electrolysis operation the cells were electrochemically characterised by means of i-V characteristics and electrochemical impedance spectroscopy measurements including a long-term test over 2000 hours. The results of electrochemical performance and long-term durability tests of both single cells and single repeating units (cell including metallic interconnect) are reported. During electrolysis operation at an operating temperature of 850 °C a cell voltage of 1.28 V was achieved at a current density of -1.0 A cm-2; at 800 °C the cell voltage was 1.40 V at the same operating conditions. The impedance spectra revealed a significantly enhanced polarisation resistance during electrolysis operation compared to fuel cell operation which was mainly attributed to the hydrogen electrode. During a long-term test run of a single cell over 2000 hours a degradation rate of 3.2% per 1000 hours was observed for operation with steam content of 43% at 800 °C and a current density of -0.3 Acm-2. Testing of a single repeating unit proved that a good contacting of cell and metallic interconnect is of major importance to achieve good performance. A test run over nearly 1000 hours showed a remarkably low degradation rate.

scholarly journals Performance of Single Electrode-Supported Cells Operating in the Electrolysis Mode

2009 ◽  
Author(s):  
J. E. O’Brien ◽  
G. K. Housley ◽  
D. G. Milobar ◽  
Nathalie Petigny
Keyword(s):  
Hydrogen Production ◽  
Gas Flow ◽  
Single Cells ◽  
Cell Performance ◽  
Steam Consumption ◽  
Electrolysis Cells ◽  
Consumption Rates ◽  
Cell Test ◽  
Current Characteristics ◽  
Electrolysis Mode

An experimental study is under way to assess the performance of electrode-supported solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900°C. Results presented in this paper were obtained from single cells, with an active area of 16 cm2 per cell. The electrolysis cells are electrode-supported, with yttria-stabilized zirconia (YSZ) electrolytes (∼10 μm thick), nickel-YSZ steam/hydrogen electrodes (∼1400 μm thick), and manganite (LSM) air-side electrodes. The experiments were performed over a range of steam inlet mole fractions (0.1–0.6), gas flow rates, and current densities (0 to 0.6 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. On a molar basis, the steam consumption rate is equal to the hydrogen production rate. Cell performance was evaluated by performing DC potential sweeps at 800, 850, and 900°C. The voltage-current characteristics are presented, along with values of area-specific resistance as a function of current density. Long-term cell performance is also assessed to evaluate cell degradation. Details of the custom single-cell test apparatus developed for these experiments are also presented.

scholarly journals Investigation of off-design characteristics of solid oxide electrolyser (SOE) operated in endothermic conditions

2019 ◽  
Vol 137 ◽  
pp. 01029 ◽  
Author(s):  
Konrad Motylinski ◽  
Michał Wierzbicki ◽  
Stanisław Jagielski ◽  
Jakub Kupecki
Keyword(s):  
Power Plants ◽  
Renewable Energy Sources ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Key Issues ◽  
Design Characteristics ◽  
Power To Gas ◽  
Solid Oxide Cell ◽  
Electrolysis Mode

One of the key issues in the energy production sector worldwide is the efficient way to storage energy. Currently- more and more attention is focused on Power-to-Gas (P2G) installations- where excess electric power from the grid or various renewable energy sources is used to produce different kind of fuels- such as hydrogen. In such cases- generated fuels are treated as energy carriers which- in contrast to electricity- can be easy stored and transported. Currently- high temperature electrolysers- based solid oxide cells (SOC)- are treated as an interesting alternative for P2G systems. Solid oxide electrolysers (SOE) are characterized as highly efficient (~90%) and long-term stable technologies- which can be coupled with stationary power plants. In the current work- the solid oxide cell stack was operated in electrolysis mode in the endothermic conditions. Based on the gathered experimental data- the numerical model of the SOC stack was created and validated. The prepared and calibrated model was used for generation of stack performance maps for different operating conditions. The results allowed to determine optimal working conditions for the tested stack in the electrolysis mode- thus reducing potential costs of expensive experimental analysis and test campaigns.

scholarly journals Recent Advances in High Temperature Electrolysis at Idaho National Laboratory: Stack Tests

2012 ◽  
Author(s):  
Xiaoyu Zhang ◽  
James E. O’Brien ◽  
Robert C. O’Brien ◽  
Joseph J. Hartvigsen ◽  
Greg Tao ◽  
...  
Keyword(s):  
High Temperature ◽  
Large Scale ◽  
National Laboratory ◽  
Solid Oxide ◽  
Idaho National Laboratory ◽  
Systems Research ◽  
Degradation Rates ◽  
Solid Oxide Electrolysis ◽  
Electrolysis Mode

High temperature steam electrolysis is a promising technology for efficiently sustainable large-scale hydrogen production. Solid oxide electrolysis cells (SOECs) are able to utilize high temperature heat and electric power from advanced high-temperature nuclear reactors or renewable sources to generate carbon-free hydrogen at large scale. However, long term durability of SOECs needs to be improved significantly before commercialization of this technology. A degradation rate of 1%/khr or lower is proposed as a threshold value for commercialization of this technology. Solid oxide electrolysis stack tests have been conducted at Idaho National Laboratory to demonstrate recent improvements in long-term durability of SOECs. Electrolyte-supported and electrode-supported SOEC stacks were provided by Ceramatec Inc., Materials and Systems Research Inc. (MSRI), and Saint Gobain Advanced Materials (St. Gobain), respectively for these tests. Long-term durability tests were generally operated for a duration of 1000 hours or more. Stack tests based on technologies developed at Ceramatec and MSRI have shown significant improvement in durability in the electrolysis mode. Long-term degradation rates of 3.2%/khr and 4.6%/khr were observed for MSRI and Ceramatec stacks, respectively. One recent Ceramatec stack even showed negative degradation (performance improvement) over 1900 hours of operation. A three-cell short stack provided by St. Gobain, however, showed rapid degradation in the electrolysis mode. Optimizations of electrode materials, interconnect coatings, and electrolyte-electrode interface microstructures contribute to better durability of SOEC stacks.

scholarly journals Microstructure Evolution in a Solid Oxide Fuel Cell Stack Quantified with Interfacial Free Energy

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3476
Author(s):  
Tomasz A. Prokop ◽  
Grzegorz Brus ◽  
Janusz S. Szmyd
Keyword(s):  
Free Energy ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Microstructure Evolution ◽  
Ion Beam ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Long Term Performance ◽  
Term Performance

Degradation of electrode microstructure is one of the key factors affecting long term performance of Solid Oxide Fuel Cell systems. Evolution of a multiphase system can be described quantitatively by the change in its interfacial energy. In this paper, we discuss free energy of a microstructure to showcase the anisotropy of its evolution during a long-term performance experiment involving an SOFC stack. Ginzburg Landau type functional is used to compute the free energy, using diffuse phase distributions based on Focused Ion Beam Scanning Electron Microscopy images of samples taken from nine different sites within the stack. It is shown that the rate of microstructure evolution differs depending on the position within the stack, similar to phase anisotropy. However, the computed spatial relation does not correlate with the observed distribution of temperature.

scholarly journals Development of catalytic combustion and CO2 capture and conversion technology

2021 ◽  
Author(s):  
Zhibin Yang ◽  
Ze Lei ◽  
Ben Ge ◽  
Xingyu Xiong ◽  
Yiqian Jin ◽  
...  
Keyword(s):  
Power Generation ◽  
Fuel Cell ◽  
Catalytic Combustion ◽  
Coal Gasification ◽  
Solid Oxide ◽  
Multi Scale ◽  
Electrolysis Cells ◽  
Integrated Gasification ◽  
Solid Oxide Electrolysis Cells ◽  
Sofc Stacks

AbstractChanges are needed to improve the efficiency and lower the CO2 emissions of traditional coal-fired power generation, which is the main source of global CO2 emissions. The integrated gasification fuel cell (IGFC) process, which combines coal gasification and high-temperature fuel cells, was proposed in 2017 to improve the efficiency of coal-based power generation and reduce CO2 emissions. Supported by the National Key R&D Program of China, the IGFC for near-zero CO2 emissions program was enacted with the goal of achieving near-zero CO2 emissions based on (1) catalytic combustion of the flue gas from solid oxide fuel cell (SOFC) stacks and (2) CO2 conversion using solid oxide electrolysis cells (SOECs). In this work, we investigated a kW-level catalytic combustion burner and SOEC stack, evaluated the electrochemical performance of the SOEC stack in H2O electrolysis and H2O/CO2 co-electrolysis, and established a multi-scale and multi-physical coupling simulation model of SOFCs and SOECs. The process developed in this work paves the way for the demonstration and deployment of IGFC technology in the future.

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