bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Gas Void Fraction on Electrode Performance in Industrial Alkaline Water Electrolysis
Authors: Gäde Felix , Möller Jonatan , Turek Thomas , Becker Maik 
Published: December 2024

In alkaline water electrolysis cells with an electrolyte gap between the electrodes, the cell's internal resistance increases when the gas void fraction in the electrolyte rises (Figure 1 a). Bongenaar-Schlentner et al. [1] were able to show this in their work already in 1985. As laboratory cells are usually significantly lower in height than industrial cells and the flow velocities [2] are typically higher than during technical operation, the influence of the gas void fraction within the cell has been paid little attention to date.
Cell heights of more than 1 m with a zero-gap arrangement are currently used in the industry [3, 4]. The influence of the gas void fraction on the efficiency in this cell configuration needs further experimental investigations, as the gas evolves in the void of the cell and does not necessarily affect the area in between them. However, it can be expected that the gas void fraction and the bubble size distribution impair the wetting of the electrode, the detachment of gas bubbles, the mass transport to the electrode and the wetting of the separator, to name just a few of the possible effects.
To emulate these effects in a real industrial-scale cell, different gas void fractions were generated in a lab-scale cell through gas addition corresponding to the gas flow rate of the industrial-scale cell at variable heights (Figure 1 b). To evaluate the influence on the current density, chronoamperometry was applied. The inlet temperature and electrolyte flow rate were varied within industrially relevant operating conditions, and the effect of different cell internals was studied.
It was observed that the influence of the additional gas is considerable, decreasing the local cell current up to 20 % at high gas void fractions. The results obtained were compared with those of a pilot plant with full-size cells, showing significant electrode utilization differences over the cell height.
This experimental investigation is a good starting point for further investigations on the effect of the gas-void fraction on the electrode performance and can lead to improved cell designs.

References

[1] B. E. Bongenaar-Schlentner, L. J. J. Janssen, S. J. D. Van Stralen, E. Barenbrecht, Journal of Applied Electrochemistry. 1985, (15), 537–548.
[2] M. T. Groot, J. Kraakman, R. L. Garcia Barros, International Journal of Hydrogen Energy. 2022, (47), 34773-34783, DOI: https://doi.org/10.1016/j.ijhydene.2022.08.075.
[3] “Atmospheric Alkaline Electrolyser – Nel Display,” https://display.nelhydrogen.com/product/atmospheric-alkaline-electrolyser-a-series/ (Accessed on April 12, 2024), n.d.

[4] “WEW - water electrolysis works,” https://wewhydrogen.com (Accessed on April 16, 2024), n.d.

Figure 1
Experimentally-Validated CFD Model of an Anhydrous HCl Electrolyzer
Authors: Likit-anurak Kris , Teel Hunter , Shimpalee Sirivatch , Meekins Benjamin 
Published: December 2024

Chlorine is an important chemical used in many everyday products1. Most Cl2 has been produced from brine by the chlor-alkaline process, which also produces NaOH and H2 as byproducts2,3. Not only can the chlor-alkaline process produce Cl2, but Cl2 can also be generated from electrolysis of HCl. Polybenzimidazole (PBI) membranes, which are high temperature proton exchange membranes, have been shown to decrease cell potential in the oxygen depolarized cathode (ODC) HCl electrolyzer compared to Nafion membrane4,5. Because PBI membranes are acid-tolerant and do not require humidity, they were used to develop a fully anhydrous HCl electrolyzer that could generate dry H2 and Cl2 from anhydrous HCl with a single pass conversion efficiency approaching 100%6. Anhydrous HCl is a highly corrosive and toxic gas which could injure researchers and damage equipment if it leaked during an experiment. This risk is especially prominent when using high HCl flow rates or applying back pressure to the electrolyzer. To eliminate the risk, computational fluid dynamics (CFD) software was used to enhance the understanding of the transport phenomena in the electrolyzer and aid improvement of the electrolyzer performance.
We will show the development of the CFD model of the fully anhydrous HCl electrolyzer based on experiments using gel-type PBI and densified PBI prepared two separate ways. The CFD model can accurately predict electrolyzer performance and guide optimization of the anhydrous HCl electrolyzer. We show that cell temperature, HCl flow rate, and cell back-pressure can be optimized to improve electrolyzer performance. We also discuss potential pitfalls of the electrolyzer, especially when considering scale-up to industrial processes.

Reference

EuroChlor, (2016) https://www.eurochlor.org/wp-content/uploads/2021/04/02-The-Chlorine-Tree-Infosheet.pdf.

P. Schmittinger, Chlorine: Principles & Industrial Practice, 1st ed., p. 254, Wiley-VCH, (2000).

EuroChlor, (2023) https://www.chlorineindustryreview.com/wp-content/uploads/2022/08/Industry-Review-2021-2022.pdf.

L. A. Murdock and B. C. Benicewicz, Macromolecules, 56, 2729–2735 (2023).

K. Likit-anurak et al., ACS Appl. Energy Mater., 6, 5429–5434 (2023).

K. Likit-anurak et al., Int. J. Hydrog. Energy, 47, 26859–26864 (2022).
High-Performance Fuel Cell with Integrated Flow Distribution in Porous Transport Layer for Heavy-Duty Vehicular Applications
Authors: Sharma Preetam , Owejan Jon , Esan Oladapo Christopher , Fields Garrett , Aaron Douglas S , Mench Matthew M 
Published: December 2024

The U.S. Department of Energy (DOE) interim (2030) targets for polymer electrolyte fuel cells (PEFCs) in heavy duty vehicle applications call for reduced system cost (US $80/kW), increased peak efficiency (68%), and longer system lifetime (25,000 hrs) [1]. Designing high-performance, durable, low-temperature hydrogen fuel cells involves intricate trade-offs between cell-level geometries and materials, as well as considering system-level complexities and efficiencies. Optimal reactant gas management, particularly oxygen transport to the cathode, is a crucial part of the design process. Despite efforts to enhance convective mixing and reduce liquid water accumulation through novel flow distribution architectures, recent commercialization trends favor formed bipolar plates with a parallel/serpentine channel architecture. These plates with flow distribution channels prove to be the most cost-competitive for heavy-duty automotive applications. Porous and high-pressure-loss flow channel networks, while promising in performance under specific operating conditions, fall short in justifying the additional cost or parasitic power associated with implementation in commercial systems [2]. This study introduces a hybrid porous layer [3],[4] with organized convection pathways that significantly improves performance compared to conventional bipolar plates. Exceptional performance (see Figure 1) is demonstrated across diverse operating conditions (e.g. wet, cold conditions up to dry, hot). The results of this study offer the potential to achieve high performance with reduced weight, as well as manufacturing and assembly cost using this hybrid architecture.

References:

[1] D. A. Cullen, K. C. Neyerlin, R. K. Ahluwalia, R. Mukundan, K. L. More, R. L. Borup, A. Z. Weber, D. J. Myers, and A. Kusoglu, “New roads and challenges for fuel cells in heavy-duty transportation,” Nat Energy, vol. 6, pp. 462–474, 2021, doi: 10.1038/s41560-021-00775-z.
[2] G. Zhang, Z. Qu, W. Q. Tao, X. Wang, L. Wu, S. Wu, X. Xie, C. Tongsh, W. Huo, Z. Bao, K. Jiao, and Y. Wang, “Porous Flow Field for Next-Generation Proton Exchange Membrane Fuel Cells: Materials, Characterization, Design, and Challenges,” Chemical Reviews, vol. 123, no. 3. American Chemical Society, pp. 989–1039, Feb. 08, 2023. doi: 10.1021/acs.chemrev.2c00539.
[3] P. Sharma, J. Owejan, D. Aaron, and M. M. Mench, “Porous Carbon Fiber Flow Fields for Heavy-Duty Polymer Electrolyte Fuel Cell (PEFC) Applications,” ECS Meeting Abstracts, vol. MA2023-01, no. 38, p. 2255, Aug. 2023, doi: 10.1149/MA2023-01382255mtgabs.
[4] J. P. Owejan and S. G. Goebel, “Performance evaluation of porous gas channel ribs in a polymer electrolyte fuel cell,” J Power Sources, vol. 494, May 2021, doi: 10.1016/j.jpowsour.2021.229740.

Figure 1
Numerical Modeling of a Polymer Electrolyte Membrane Fuel Cell for Electric Aircraft Propulsion
Authors: Oka Haruya , Katsuki Yusaku , Nakajima Hironori , Inoue Chihiro 
Published: December 2024

Electrified propulsion systems with hydrogen-fueled fuel cells can potentially reduce carbon dioxide emissions from aircraft. However, achieving a substantial increase in the gravimetric/volumetric power density of fuel cell systems poses a considerable challenge. In this study, we focus on polymer electrolyte membrane fuel cells (PEMFCs) working between 100 and 200°C. To design an optimized PEMFC structure for an electric aircraft, we have developed a numerical model that employs the finite element method (FEM) (COMSOL Multiphysics) to couple electrochemistry, gas diffusive and convective transports, and heat transfer in fuel cell components such as separators, gas flow channels, gas diffusion layers, catalyst layers, and a PEM1)2). We thereby three-dimensionally visualized the current, hydrogen, oxygen, and water vapor concentration distributions, as well as the temperature distributions, assuming conditions in aircraft operations. Moreover, we developed a machine learning model from the data outputs of the FEM model, which serves as training data, to reduce the computational costs for the fuel cell stack design incorporated in a system-level numerical model.
Acknowledgement
This study is based on results obtained from a project, JPNP14004, commissioned by the New Energy and Industrial Technology Development (NEDO). We are indepted to Boeing Research & Technology, Boeing Japan for their support and discussions. We are also grateful to Professor Motoaki Kawase of Kyoto University for his fruitful suggestions. Thanks are offered to Professor Kohei Ito and Associate Professor Tatsumi Kitahara of Kyushu University for their valuable discussions.
References
1) Ö. Aydın, T. Ochiai, H. Nakajima, T. Kitahara, K. Ito, Y. Ogura, J. Shimano, Mass transport limitation in inlet periphery of fuel cells: Studied on a planar Solid Oxide Fuel Cell, Int. J. Hydrogen Energy, 43 (2018) 17420–17430. https://doi.org/10.1016/j.ijhydene.2018.07.030
2) X. Wang, H. Nakajima, Y. Iwanaga, K. Ito, Numerical and experimental investigation of a cathode-supported microtubular solid oxide electrolysis cell from current and temperature variations in-situ assessed with electrode-segmentation method, J. Energy Storage, 72 (2023) 108459. https://doi.org/10.1016/j.est.2023.108459
Diagnosing the Nature of Oxygen Site in Yttrium Doped Barium Calcium Niobates and Its Impact Towards Electrochemical Oxidative Coupling of Methane
Authors: Ramaiyan Kannan , Benavidez Angelica , Garzon Fernando H. 
Published: December 2024

Effective conversion of methane into value added chemicals such as ethylene will help reduce its venting and flaring from oil and gas wells. Oxidative coupling of methane (OCM) is shown to produce ethylene although over oxidation products such as CO2 and CO reduce the C2 hydrocarbon selectivity. The industrial target for OCM process is a single pass conversion of at least 30% and a C2 selectivity around 80% although catalysts with satisfactory performance has not been identified yet despite four decades of intense research.1 Electrochemical OCM is recently gaining renewed interest due the ability to control the conversion rate and product selectivity though temperature and applied potential. We demonstrated a potential dependent C2 selectivity using Fe and Ca codoped barium niobates as E-OCM catalysts.2–4 However, introduction of yttrium as a dopant in barium calcium niobate (BCNY) resulted in a remarkable change in its electrical conductivity and methane activation properties. We present our results on BCNY’s methane activation properties and possible correlation between the nature of oxygen species in the BCNY crystal matrix. Electrical conductivity measurements, E-OCM measurements and temperature programed reactions in oxidizing and reducing conditions are utilized to establish the role of yttrium and compare with other transition metal dopants such as Fe and Ni.
References

Zavyalova U, Holena M, Schlögl R, Baerns M. Statistical Analysis of Past Catalytic Data on Oxidative Methane Coupling for New Insights into the Composition of High-Performance Catalysts. ChemCatChem. 2011;3(12):1935-1947. doi:10.1002/cctc.201100186

Ramaiyan K, Denoyer LH, Benavidez A, Garzon FH. Role of Dopants in Fine-Tuning the Electrical and Catalytic Properties of Barium Niobate Perovskites Towards High-Temperature Electrolyzer Application. ECS Trans. 2023;111(6):1139. doi:10.1149/11106.1139ecst

Denoyer LH, Benavidez A, Garzon FH, Ramaiyan KP. Highly Stable Doped Barium Niobate Based Electrocatalysts for Effective Electrochemical Coupling of Methane to Ethylene. Adv Mater Interfaces. 2022;9(27):2200796. doi:10.1002/admi.202200796

Denoyer LH, Benavidez A, Brearley A, Ramaiyan K, Garzon FH. Chemical Stability of BaMg0.33Nb0.67-XFexO3-δ in High Temperature Methane Conversion Environments. ECS Trans. 2023;111(6):587. doi:10.1149/11106.0587ecst
Resolving the Impact of Sr and Ni Diffusion on Moderate-Temperature Sintered BaZr0.44Ce0.36Y0.2O3/SrZr0.4Ce0.4Y0.1O3–NiO Half-Cells Interface for PCEC/PCFC
Authors: Kwati Leonard , Povstugar Ivan , Kindelmann Moritz , Meulenberg Wilhelm , Ishihara Tatsumi , Matsumoto Hiroshige 
Published: December 2024

Proton-conducting solid oxide electrolytes are poised to play a transformative role in steam electrolysis (PCEC) and fuel cells (PCFC) application at moderate to low temperatures, given their high ionic conductivity and inherent advantages in the gas flow configuration over traditional solid oxide cells. However, their refractory nature necessitates high sintering temperatures to ensure sufficient densification which also compromises the protonic conductivity of the material. This paper investigates the impact of Sr and Ni segregation at the electrode/electrolyte interface in BaZr0.44Ce0.36Y0.2O3 (BZCY(54)8/92) proton conductinghalf-cells using a combination of high-resolution STEM-EDX, 3-dimensional atom probe tomography (APT), and Raman spectroscopy to understand structural modifications of the half-cells upon sintering at varying temperatures. Our half-cells are fabricated using an industrially established inverse tape-casting route with NiO-SrZr0.5Ce0.4Y0.1O3-δ as the substrate, ensuring minimal warping and no cracks in the end-fired state. After co-sintering at 1300 °C for 5 hours, the tri-layered green tapes achieved dense, gas-tight electrolyte layers with a He leakage rate well within the threshold necessary for cell operation (~5 × 10–5 hPa dm3 (s cm2)–1). Using Ba0.5La0.5CoO3−δ as the air electrode demonstrates remarkable capabilities and endurance within the 450-600°C temperature range, achieving a peak power density of 1.13 W cm-2 at 600 °C in the fuel cell mode and a high current density of 1.5 A cm-2 at 1.3 V in the electrolysis mode. Furthermore, It is apparent from the latter techniques that upon sintering above 1350 °C, the electrolyte material undergoes evident structural changes with new crystal defects that affect the perovskite host. Ni diffuses into the electrolyte layer and gets dissolved in the bulk while some segregate at the grain boundary, below monolayer coverage in either case (GNi 2.0 at%/nm2).
Acknowledgment: The authors gratefully acknowledge financial support through JSPS KAKENHI Grant-in-Aid for Scientific Research (C), No. 19K05672, NEDO (International collaboration) JPNP20005, JSPS Core-to-Core (Solid Oxide Interfaces for Faster Ion Transport) and WPI-I2CNER sponsored by the World Premier International Research Center Initiative (WPI), MEXT, Japan.
Influence of Local Environment Under Polarization on Wettability of Ni/YSZ Interface
Authors: Ihara Sota , Muroyama Hiroki , Matsui Toshiaki 
Published: December 2024

In solid oxide fuel cells (SOFCs) and solid oxide electrolysis cells (SOECs), degradation of hydrogen electrode during long–term operation is one of the issues to be solved. Migration and aggregation of Ni particles are major factors of this degradation, and especially after steam electrolysis operation, intense Ni migration has been observed at the hydrogen electrode/electrolyte interface [1]. This phenomenon is assumed to be related to the change in wettability of the Ni/electrolyte interface under polarization [2]. A quantitative measurement of interface wettability is the concept of contact angle. It is known that the contact angle is determined by the balance between the surface tension of contacting materials and the interfacial tension. Contact angle analysis is usually used for liquid–solid interfaces, but it has also been suggested to be useful for the characterization of solid metal–oxide interfaces [3]. Therefore, the aim of this study was to directly measure the contact angle between Ni and YSZ electrolyte under various conditions in order to quantify the changes in wettability at the interface.
Ni thin film electrodes were prepared by sputtering Ni on YSZ electrolyte. Using this model electrode, electrochemical measurements were performed under open circuit holding or a potentiostatic operation (SOFC operation or SOEC operation) at high temperatures. Subsequently, postmorterm analysis of the samples was performed using a Focused Ion Beam–Scanning Electron Microscope (FIB–SEM). Using the cross–sectional SEM images of the model electrode, the contact angle was calculated by distinguishing the three phases of Ni, YSZ, and pores based on the difference in contrast of each phase. The analysis revealed that the wettability of the Ni/YSZ electrolyte interface changed depending on the operation mode. Specifically, the contact angle after SOEC operation increased compared to values after open circuit holding or SOFC operation. This phenomenon is thought to be related to changes in oxygen potential.
Acknowledgements
This paper is based on results obtained from a project, JPNP20003, commissioned by the New Energy and Industrial Technology Development Organization (NEDO).
References
[1] M.B. Mogensen,
et al.
,
Fuel Cells
, 17, 434 (2017).
[2] Z. Jiao and N. Shikazono,
Acta Materialia
, 135, 124 (2017).
[3] H. Kishimoto,
et al.
,
Solid State Ion.
, 225, 65 (2012).
Surface Proton Conductivity of Sm-Doped SrCeO3-BaCeO3 Solid Solution Ceramic and Thin Film
Authors: Tabuchi Riku , Morizane Ryota , Notake Go , Higuchi Tohru 
Published: December 2024

Solid oxide fuel cell (SOFC) device that generates electrical power by hydrogen or oxygen gas is one
of clean and renewable energy sources. SOFC at medium temperature (MT) range operating at 400-
600 °C is highly attractive because operating time become shorter than SOFC using YSZ ceramic
electrolyte. Although the ion conduction at MT been extensively studied in acceptor-doped BaCeO3
or BaZrO3 bulk ceramics, no practical ion conductivity has been achieved so far [1][2]. Although Y-SrCeO3 and Y-BaCeO3 have confirmed proton conductivity at medium temperature (MT), so we focused on SrCeO3 and BaCeO3, which are extremely chemically stable perovskite-type oxides [3][4].
In this study, we have prepared the Sm-doped BaCeO3-SrCeO3 (Sr0.7Ba0.3Ce0.8Sm0.2O3-δ: SBCS)
composite thin film on Al2O3 (0001) substrate with the aim of improving chemical stability and high conductivity, and investigated its ionic conduction [5].
The SBCS thin films were prepared on Al2O3 (0001) substrates by RF magnetron sputtering using ceramic targets. The flow rate of Ar gas controlled by a mass-flow controller was kept at approximately 2.81 sccm. The pressure of Ar gas was fixed at 3.5 × 10−3 Torr during the deposition. The prepared thin films were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and A.C impedance method using a frequency response analyzer.
The XRD pattern results showed a 121 peak and a 242 peak, indicating successful crystallization of the films. The prepared thin films exhibit plane index of 121.
Figure 1 shows an Arrhenius plot of the conductivity of the wet-annealed SBCS thin films with various thicknesses. The conducting carrier is considered to be proton, although the contribution of oxide ion also exists. These conductivities exhibit relatively high conductivity in this temperature region. Moreover, the conductivity is enhanced by the addition of Ba, as indicated by the improved conductivity compared to SrCe0.8Sm0.2O3-δ (SCSO). A thinner film thickness results in higher conductivity. This is believed to be due to the contribution of surface proton conductivity.
Reference
[1] D.Pergolesi et al., NATURE MATERIALS, 9, (2010), 846-852
[2] T.Hibino et al. ,J Phys Chem,B ,Vol.105,No.46,2001
[3] S. Shin et al., Solid State Ionics (1990)
[4] T. Higuchi et al., Solid State Ionics, 270 (2015) 1-5.
[5] E. Gorbova,Journal of Power Sources,181,(2008)207

Figure 1
Mixed Protonic and Electronic Conduction in N-Type Oxide Semiconductor MgIn2O4 Under Hydrogen Atmosphere
Authors: Yamasaki Tomoyuki , Kudo Saki , Omata Takahisa 
Published: December 2024

There is an emerging interest in mixed protonic-electronic conductors for use as hydrogen-permeable membranes and electrodes of fuel cell and water electrolyzer working at 300–500℃. Up to now, the research for mixed protonic-electronic conductors has been limited to a common approach: an acceptor cation is doped to a perovskite-type oxide, creating positively charged compensating defects, notably oxygen vacancy, then hydrate these1;
H2O(g) + VO
•• + OO
× → 2OHO
•.
Since the doped acceptor has an effective negative charge relative to the species they replace, the introduced protons are plausibly trapped surrounding the acceptors (proton trapping). Therefore, to achieve mixed protonic-electronic conductors with high proton conductivity at intermediate temperatures.
In n-type oxide semiconductors, such as In2O3, SnO2, and ZnO, hydrogen is a ubiquitous impurity that acts as an electron donor. Hydrogen is incorporated into interstitial sites and forms a shallow donor state2, according to
H2(g) → 2H
i

• + 2e’.
Here, we reveal that the interstitial proton introduced via this mechanism conducts through n-type conducting MgIn2O4
3 at intermediate temperatures. We show that hydrogen is incorporated into MgIn2O4 in a hydrogen atmosphere, leading to an increase in the electronic conductivity. To assess the partial proton conductivity of hydrogen-incorporated MgIn2O4, we prepared an electron-blocking cell. A MgIn2O4 thin film was deposited by RF magnetron sputtering on a proton-conducting phosphate glass4. We conducted chronoamperometry and electrochemical impedance spectroscopy for the electron-blocking cell. The proton partial conductivity of MgIn2O4 was determined as 1.1×10−6 Scm−1 at 250℃. In the presentation, the proton mobility of MgIn2O4 will be discussed in comparison with perovskite-type proton conductors, showing that n-type conducting oxides are promising for mixed protonic-electronic conductors.

References

Kreuer, K.-D. Proton Conductivity: Materials and Applications. Chem. Mater.
8, 610–641 (1996).

Kılıç, Ç. & Zunger, A. n-type doping of oxides by hydrogen. Appl. Phys. Lett.
81, 73–75 (2002).

Ueda, N. et al. New oxide phase with wide band gap and high electroconductivity, MgIn2O4. Appl. Phys. Lett.
61, 1954–1955 (1992).

Ishiyama, T. et al. Transport properties of proton conducting phosphate glass: An electrochemical hydrogen pump enabling the formation of dry hydrogen gas. Int. J. Hydrog. Energy
44, 24977–24984 (2019).