bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Optimised PEM Electrolyzer Bipolar Plates for MW Stacks Enabling Efficient Operation and Industrial Manufacturing
Authors: Bouwman Peter Jaime 
Published: December 2024

Green Hydrogen production has been allocated an important role as part of energy transition strategy to reduce our CO2 footprint. Electrolyzer stacks have been developed and commercialized to convert pure water into hydrogen and oxygen. Large multinational companies have now entered the “field of hydrogen” with the intent and capacity to industrialise and automate stack manufacturing, thus bringing down costs through the economy of scale.
Our core strength is focused around the bipolar plate design, material choice and protective coating types, for application in an optimized water-electrolyzer stack for PEM or AEM applications. Schaeffler [1] is driving additional technological development projects with strong financial backing of European (CHP) and German funding (H2Giga). PEM water electrolysis is regarded as powerful technology, bringing advantages of limited installation footprint, broad range of operating conditions, especially in terms of dynamic load range and featuring high efficiency between 75-90% (based on HHV) [2].
In this work we estimate how much the stack technology can be improved further by leveraging formed BPP metal structures and optimizing the structural elements and component design using CFD. Especially when scaling stack hardware to larger capacity, there is much emphasis on enhanced thermal management to avoid hot-spots and mitigate non-uniform degradation mechanisms and premature stack failure. Simulation results will show how flow designs could be adapted maintain uniform conditions when scaling up the active area or adding more cells to the stack.
Simulation results will be compared with operational stack data for small screener stacks up to large MW-level cell platforms. We show how we can optimize flowfield flow structures, staying within the manufacturing limits of the material at hand, being titanium or stainless steel. Both processes rely on simulation software [3] to answer many critical questions, including how to identify the most influential parameters for hydrogen production, for example: current density regime, pitch between plate, the temperature of the feedwater, or the outflow water. Also, if there is a separate cooling loop available, we demonstrate what the ultimate thermal control solution could look like to save cost and gain operational lifetime.
The hydrogen economy benefits most from accelerating our iterative pathway towards an optimum BiPolar Plate design comprising a structured flowfield for uniform flow distribution and a material composition bringing overall cost/performance benefits. Once the industry has agreed upon a standardized electrolyzer stack geometry, our combined economy of scale will have a greater positive impact on the business case.
References
[1] K. Rosenfeld, The Stern Stewart Institute, periodical #27 (2023) 20-27.
[2] Y. Wang et.al., Energy Environ. Sci., 15 (2022) 2288-2328.
[3] P. Lyubarskyy, interview Imagining a Hydrogen-Powered Future Thanks to Simulation, (2023).

Figure 1
Time and Potential-Resolved Studies of Bipolar Plate Corrosion for Polymer Electrolyte Membrane Fuel Cells
Authors: Kariuki Nancy N. , Dang Ngoc K , Myers Deborah J. , Papadias Dionissios , Ahluwalia Rajesh 
Published: December 2024

Stainless steels are regarded as the reference materials for metal bipolar plates for polymer electrolyte membrane fuel cells (PEMFCs) due to their low cost and weight, high electrical conductivity, flexural strength, ease of machining, and ability to be formed into thin sheets. The main drawback is their susceptibility to corrosion in typical acidic, oxidizing environments of PEMFCs, 1,2,3 which can degrade the performance of the plate and other components of the PEMFC. The simultaneous presence of iron ions released by corrosion of the BPP and hydrogen peroxide is responsible for hydroxyl radical production, resulting in degradation of the membrane and cathode catalyst layer ionomer.4 Applying a protective coating to the metal bipolar plates is an effective way to improve its corrosion resistance.5 This work investigates corrosion rates of SS316L bipolar plates on the basis of the measured concentrations of cations (e.g., Fe, Cr, and Ni) in an aqueous electrolyte as a function of applied potential and corrosion environment.
Techniques employing electrochemical flow cells (EFC) directly coupled to an inductively-coupled plasma mass spectrometer (ICP-MS) allow for more precise time- and potential-resolved detection of dissolved species. This work will report real-time data on leaching of Fe, Cr, and Ni from SS316L substrates subjected to potential cycles using a flow-through electrochemical cell coupled with an on-line ICP-MS instrument, with sub-part per billion (ppb or μg/L) sensitivity, providing the ability to resolve dissolution during potential scans. The results of this work provide a baseline for studying the efficacy of stainless steel bipolar plate coatings in mitigating degradation of PEMFCs.

References

Leng, P. Ming, D. Yang, C. Zhang. J. of Power Sources 451, (2020) 227783.

Kumagai, S.-T. Myung, T. Ichikawa, H. Yashiro, Y. Katada, J. Power Sources 202 (2012) 92.

D. Papadias, R. K. Ahluwalia, J. K. Thomson, H. M. Meyer III, M. P. Brady, H. Wang, J. A. Turner, R. Mukundan, R. Borup. J. of Power Sources 273 (2015) 1237.

Elferjani, G. Serre, B. Ter-Ovanessian, B. Normand. International Journal of Hydrogen Energy 46, (2021), 32226-32241.

Liu, Q. Jia, B. Zhang, Z. Lai, L. Chen. International Journal of Hydrogen Energy 47, (2022) 22915.

Acknowledgements

This research is supported by the U.S. Department of Energy, Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office under the auspices of the M2FCT consortium. Argonne National Laboratory is managed for the U.S Department of Energy by the University of Chicago Argonne, LLC under contract DE-AC-02-06CH11357.
Optimization Potential for Operating PEMFC Systems Under High-Altitude Conditions
Authors: Murschenhofer Dominik , Settele Jonas , Stengele Simon , Bänsch Cornelie 
Published: December 2024

The PEMFC technology is on the rise to be implemented as climate neutral power source in next generation aircraft. Despite the PEMFC’s high efficiency at ground level, it suffers from severe power losses when it is operated under high-altitude conditions, i.e. low ambient pressure and temperature.
In this study, a fuel cell system consisting of a 120 cells PEMFC stack, an air blower, an anode recirculation pump and a cooling unit is investigated experimentally inside an altitude test chamber, where the ambient pressure and temperature can be controlled. In an extensive parameter study, the fuel cell’s cathode stoichiometry and the stack temperature are varied while the system is operated at different average cell voltage levels under high-altitude conditions. The ambient pressure is varied between 1000 and 500 hPa, the latter corresponding to an altitude of 5600 m. The air blower inflow temperature is varied between 40 and -30 °C. By means of statistical design of experiment methods an empirical model is derived from the measurements, which represents the system performance depending on the five-dimensional parameter space, i.e. cathode stoichiometry, stack temperature, average cell voltage, ambient pressure and blower inflow temperature.
The model is evaluated in order to identify the optimal parameter configurations for stoichiometry and stack temperature control, yielding the maximum system net power at high-altitude operation. The results show that the negative effects in terms of power losses due to low ambient pressure prevail over low air temperature. However, the low temperature is non-negligible in terms of the air density, affecting the required blower power to maintain a certain stoichiometry and consequently also affecting the system net power. When operating at high-altitude conditions with optimized control parameters, the resulting net power output is significantly higher compared to the net power output obtained with the default control parameters suggested by the manufacturer. The main reason for this power increase can be found in the optimized membrane humidification. Under high-altitude conditions, humidification becomes more sensitive to deviations from the identified optimal control parameters. The results highlight the large optimization potential through altitude-adaptive control of fuel cell systems for aviation applications.
Degradation Analysis of a PEMFC System Operated Under High-Altitude Conditions
Authors: Settele Jonas , Bänsch Cornelie , Murschenhofer Dominik 
Published: December 2024

The development of powertrains for upcoming regional aircraft based on polymer electrolyte membrane fuel cells (PEMFCs) opens a promising pathway to decarbonize the aviation sector. However, operating PEMFC systems under high-altitude conditions poses significant challenges, as performance, efficiency, and durability are affected due to the decreased ambient pressure and colder temperatures. To meet the durability requirements of aircraft components and ensure the economic competitiveness of PEMFCs, lifespan extension by mitigating degradation effects deserves high attention.
In this study, a comprehensive experimental degradation analysis is performed by operating an entire fuel cell system inside a temperature-controlled low-pressure chamber. The system under investigation is a self-humidifying 120 cells PEMFC stack, equipped with additional balance-of-plant components including an air blower, a recirculation pump, and a cooling unit. In course of several characterization test campaigns, the non-pressurized PEMFC system is operated for approximately 600 hours at various ambient conditions. These conditions include ambient pressures from 1000 to 500 hPa, corresponding to altitudes ranging from sea level to 18300 ft (5600 m), respectively. The air blower intake temperatures are varied from 40 to -30 °C. To keep track of the system degradation, standardized preconditioning procedures are performed at the beginning of each testing day. During the test campaigns, polarization curves are recorded on a regular basis. In order to remove reversible degradation, reconditioning procedures involving cyclic current jumps are conducted approximately every 100 hours of operation.
The impact of the various environmental conditions on the degradation behavior of the system is evaluated, with particular focus on the sensitivity to reduced ambient temperature and pressure. For the recovery of reversible voltage losses, reconditioning methods are considered to be essential and their applicability to industrial processes is assessed. Preliminary results suggest that operation at high-altitude conditions severely affects the membrane humidification and thus leads to accelerated degradation. However, by adjusting the key control parameters related to water management, such as cathode stoichiometry and stack temperature, the durability may be improved. As a consequence, it is shown, that implementing control strategies optimized for high-altitude operation is crucial not only for performance improvement but also for mitigating excessive degradation.
Dynamic Modeling of Polymer Electrolyte Membrane Water Electrolysis System and Dynamic Response
Authors: SHIN Hee-Sun , Jang Dohyung , Kim Kyong-Hwan , Lim Chang Hyuck , Kang Sanggyu 
Published: December 2024

Water electrolysis to produce hydrogen using electric energy is classified into polymer electrolyte water electrolysis, alkaline water electrolysis, solid oxide water electrolysis, and anion exchange membrane water electrolysis according to the type of electrolyte applied. Among them, polymer electrolyte membrane water electrolysis has a lower operating temperature than other types of water electrolysis, and it is possible to operate high-efficiency, high-power density hydrogen production with high current density. In addition, polymer electrolyte water electrolysis has the advantage of fast response to changes in power supply, so empirical studies for green hydrogen production linked to renewable energy are being conducted most actively compared to other water electrolysis. However, research on coupling polymer electrolyte water electrolysis with renewable energy generation with intermittent and irregular power generation has mainly focused on materials, cells, and stacks. In order to keep the hydrogen production reaction of water electrolysis stack stable under the condition of supply power fluctuation, the peripheral devices should be optimally installed and controlled.
In this study, a dynamic model of a polymer electrolyte water electrolysis system was developed using Aspen HYSYS®. To accurately predict the hydrogen production efficiency, a stack model considering electrochemical reactions and crossovers through the electrolyte was developed and internalized in a spread sheet. A heat exchanger model from the model library was used to simulate dynamic changes in the electrolyte temperature flowing through the water electrolysis stack. The developed stack model was extended to a system model by integrating the feed pump, separator, condenser, heater, and cooling system. The developed water electrolysis system model was simulated in connection with power ramp variations and renewable energy output, and the optimal operation strategy of each module unit was derived to ensure the stability of high-purity hydrogen production under transient conditions.
(Invited) A Retrospective View of the Proton Exchange Membrane Fuel Cell from Renaissance to Commercialization
Authors: Wilkinson David P. 
Published: December 2024

Initial development of the proton exchange membrane fuel cell (PEMFC) by General Electric in the 1960s and subsequent development of the technology and materials through into the 1980s showed the possibility of commercial applications. However, application of the technology during this time was mainly limited to the Gemini space program with subsequent shelving of the technology for about 20 years. From the late 1980s onwards there has been increasing activity and progress towards commercialization of PEMFC technology in a number of applications. The advancement of PEM electrolysis has also certainly benefited from earlier work on the PEM fuel cell. In some commercial applications today fuel cell technology is already competitive on an economic basis with established and highly developed incumbent technologies such as combustion technologies and other forms of power generation and storage. However, PEM technology faces other implementation challenges such as distribution and infrastructure availability. As fuel cells and electrolyzers move into full commercialization other new opportunities are arising in connecting the “Chemical Economy” with the “Electricity Economy” such as grid energy storage using power to gas, penetration of renewables into the energy mix, and chemical conversion. This is particularly important for the Net Zero 2050 plan, where fuel cells and electrolyzers along with batteries will be key electrochemical engines for the 21st Century.
Significant progress has been made with the PEMFC over the last 35 years in a number of technical areas including reliability, durability, cost reduction, operational flexibility, technology flexibility and integration, fundamental understanding, and life cycle impact. This presentation will cover some of the key developments and learnings over this period of time and provide perspectives on the progress that has been made towards commercialization. Technical progress would include such important areas as precious metal catalyst loading reduction and alternatives, reformate operation, increased power density, freeze start capability, cell reversal tolerance, and water management. In addition to a retrospective view, some of the potential future research and development directions being taken to modify conventional PEMFC technology will also be discussed.
Proton Solubilities in Candidate Protonic Ceramic Fuel Cell Air Electrode Materials from First Principles
Authors: Fisher Craig Andrew James , Taguchi Ayako , Ogawa Takafumi , Kuwabara Akihide 
Published: December 2024

Using a mixed protonic-electronic conducting oxide as the air electrode of protonic ceramic fuel cells is one strategy for increasing their electrical efficiency, as this should enable a larger particle surface area to participate in the oxygen reduction reaction. However, because of their complex defect chemistry, few studies have focused on proton solubility in electrode materials, and hence little is known about which materials are able to absorb sufficient protons to support high conductivity. To help identify materials likely to have both high protonic and electronic conductivity, we performed first-principles calculations of 3d transition metal oxide perovskites LnMO3 (Ln = La, Pr, Nd, Sm, Gd; M = Sc, V–Ni), focusing on their hydration enthalpies calculated according to
H2O+v
O
⋅⋅+OO
×→2OHO
⋅, where v
O
⋅⋅ is an oxide-ion vacancy and the proton bonds to an O atom to form a hydroxide ion, OHO
⋅.
We found that hydration becomes less favorable as the number of 3d electrons increases, i.e., as the M-O bonds become less basic. In contrast, electronic conductivity, as assessed from band structure plots and effective masses, generally increases. By comparing the hydration enthalpy to that of prototypical proton electrolyte BaZrO3, good mixed proton-hole conducting oxides are thus likely to be found using transition metals from the middle of the period (M = Cr–Co) when Ln = La. Smaller lanthanides favor easier hydration, however, so that good mixed conducting perovskites containing Fe, Co, and/or Ni may be achievable using lanthanides Pr, Nd or Sm.
Acknowledgment
This work was performed as part of the Development of Ultra-High Efficiency Protonic Ceramic Fuel Cell Devices project (JPNP20003), commissioned by the New Energy and Industrial Technology Development Organization.
Sr Doped LaScO3 Thin Film As Cathodic Functional Layers for Ni-Fe Metal Supported Protonic Ceramic Fuel Cell Using BaZr0.44Ce0.36Y0.2O3 Film
Authors: Kim HyoYoung , Ishihara Tatsumi 
Published: December 2024

Metal support proton conducting fuel cells (MS-PCFCs) is expecting as highly efficient and reliable power generation devices. In this study, porous Ni-Fe alloy support PCFCs was studied using BaZr0.44Ce0.36Y0.2O3 (BZCY) film prepared by pulsed laser deposition (PLD) method. For increasing power density, the effects of the La(Sr)ScO3 (denoted LSSc) at the cathodic interlayer were studied. BZCY film was deposited on dense NiO-NiFe2O4 oxide support by PLD, followed LSSc is deposited as a cathode functional layer (CFL). Sm0.5Sr0.5CoO3 (SSC) was used for the cathode, and then NiO-NiFe2O4 was reduced to obtain the porous metal substrate. Humidified H2 and O2 were used for fuel and oxidant, respectively. Metal support BZCY cell was successfully prepared, and open circuit potential (OCV) and maximum power density were 0.99 V and 69 mW/cm2, respectively at 600 ºC. So reasonable power density was achieved on the Ni-Fe support BZCY film. The main potential drop is occurred by ohmic resistance. Effects of the cathodic functional layer were studied, and it was found that La(Sr)ScO3 film at the interlayer between BZCY and SSC was highly effective for increasing the power density of the cell by decreasing IR loss and overpotential. The optimization of LSSc film was performed and the optimum Sr amount was 15 wt % in LSSc film and the thickness was 200 nm. The power density of MS-PCFCs with LSSc15 CFL was 405 mW/cm2 and an open-circuit voltage (OCV) was ca.1.1 V at 600 ºC, as shown in Figure 1. Due to enhanced proton conductivity, interfacial resistance and cathodic overpotential were also decreased. Insertion of LSSc CFL is highly effective for improving the performance of MS-PCFCs.
Acknowledgment; Part of this study was financially supported by New Energy and Industrial Technology Development Organization (NEDO, JPNP20003), Japan
Reference
[1] H. Sumi, H. Shimada, K. Watanabe, Y. Yamaguchi, K. Nomura, Y. Mizutani, R. M. Matsuda, M. Masashi, K. Yashiro, T. Araki, Y. Okuyama, J. Power Sources 2023, 582, 233528
[2] A,Y. Stroeva, and V. P. Gorelov. Russian Journal of Electrochemistry 2012, 48, 1079-1085

Figure 1
Operando High Temperature XRD Study of Oxygen Electrodes during SOEC Operation
Authors: Marina Olga A , Coyle Christopher , Karki Surendra B 
Published: December 2024

In this work, we attempt to correlate SOEC device performance with the properties of cell materials under real operating conditions. Operando high temperature X-ray diffraction (XRD) characterization of the oxygen electrodes was performed during actual SOEC operation in real time, at high temperatures, using the real reactive gases atmospheres, for up to 1000 hours.
State-of-the-art Ni-YSZ electrode supported SOECs were fabricated using Ni-YSZ hydrogen electrodes, 8YSZ electrolyte, GDC barrier layer, and LSCF-based electrodes. Cells were tested in potentiostatic and galvanostatic modes with 50% steam and 50% hydrogen fed to the hydrogen electrode vs ambient air at 750 and 800oC. Current or voltage were recorded in time, and electrochemical impedance data were collected periodically to monitor the changes in cell ohimic and polarization resistances. XRD scans covering 25 to 85° 2θ with 0.02° steps and a 1.1 second count time per step were initiated every hour. The resulting XRD patterns were processes to identify time-dependent changes in the oxygen electrode. The results revealed chemical changes in the LSCF phase such as appearance of FeOx/CoOx phases and further LSCF phase transition that could help to explain observed cell performance losses in time. Operando measurements allowed for real time chemical phase diagnostics and helped reveal new insights about SOEC degradation mechanisms that are difficult to explain by only post-test SEM/EDS characterization.