Abstract The automotive industry sees hydrogen‐powered fuel cell (FC) drives as a promising option with a high range and short refueling time. Current research aims to increase the profitability of the fuel cell system by reducing hydrogen consumption. This study suggests the use of an electrochemical hydrogen compressor (EHC) for hydrogen recirculation. Compared to mechanical compressors, the EHC is very efficient due to the almost isothermal conditions and due to its modular structure, can only take up a minimal amount of space in vehicles. In addition, gas separation and purification of the hydrogen takes place in an EHC, which is a significant advantage over the standard recirculation with a blower or a jet pump. The high purity of the hydrogen at the cathode outlet of the EHC, also increased partial pressure of the hydrogen at the fuel cell inlet and its efficiency. The study carried out shows that replacing the blower with the EHC reduces the hydrogen loss by purging by up to ∼95% and the efficiency of the FC system could be further improved. Thus, the EHC has a great potential for recycling hydrogen in FC systems in the automotive industry and is a great alternative to the current blower.

Abstract Liquid organic hydrogen carriers (LOHCs) are promising means for hydrogen transportation. They are compatible with existing liquid fuel transport infrastructure and enable for efficient and safe hydrogen storage and transfer over long distances. Toluene and dibenzyltoluene are considered the two most promising LOHCs. Toluene is probably a contaminant found in hydrogen released from these LOHC liquids.The impact of hydrocarbon contaminants on automotive type fuel cells has been analyzed to a limited extent, and a few species only have specific limits (CO, CO2, HCOOH, HCHO, CH4). Currently, hydrocarbons are limited to a total of 2 ppm (methane basis) in the automotive hydrogen fuel standard, ISO 14687:2019. This may lead to strict impurity levels for species from LOHC, and therefore higher costs of hydrogen purification and quality assurance.This work presents contamination studies with toluene. The measurements were conducted using a PEMFC short stack with anode recirculation and with high fuel utilization (98%). The results show no effect or only a small contamination effect with up to 20 ppm toluene, and clear contamination with 50 ppm toluene. This supports the need for more studies so that a separate limit can be defined for toluene in future versions of the ISO 14687.

Abstract A Ni/Yttria‐stabilized zirconia (YSZ) cell with a (La0.60Sr0.40)0.95Co0.20Fe0.80O3–δ cathode is tested both in fuel cell and electrolysis modes. In fuel cell mode under dry air and wet H2, the cell is operated between the open circuit voltage (OCV) and 0.4 V and reaches 330 mW cm−2 at 850 °C for 157 mL min−1 H2 supply. The influence of temperature and air or hydrogen flow rate is studied, and impedance measurements show that below 0.8 V the electrolyte becomes the more resistive part of the cell. Nevertheless, fuel utilization yields are higher under oxygen or hydrogen depletion. If it is possible at 750 °C to work at low voltage during several hours in the entire voltage range, the voltage decrease must be limited at 850 °C. The cell can also be operated under wet air. The same cell can be operated in electrolysis mode, and a power density of 340 mW cm−2 can be obtained at 0.3 V/OCV under 100 mL min−1 wet (3% H2O) 5% H2–95% Ar mixture on the fuel side and dry or wet 100 mL min−1 air flow on the air side. Nevertheless, bubbling air providing the air electrode in saltwater has an irreversible detrimental effect on the cell.

Abstract With the advantages of high energy density and low operating temperature, direct methanol fuel cell (DMFC) has been rated as the most promising portable energy device to replace the traditional lithium cell. However, the development of DMFC is limited by methanol crossover (MCO) and catalyst poisoning. To alleviate MCO, a DMFC with an integrated ultrasonic atomization fuel feeder is proposed in the present research. The open circuit voltage (OCV) and the polarization curves of the cell under a series of conditions are analyzed. The performances of the proposed DMFC are evaluated at different methanol concentrations and fuel feed rates. The mechanism of MCO is discussed from above experiments. Compared with liquid feed style, atomization feed style can reduce characteristic response time (CRT) and greatly alleviate MCO because the DMFC obtains a larger OCV value. It can be found from our experiments that atomization feed style can effectively improve cell performance and energy density. Moreover, atomization feed style under different methanol concentrations can obtain the best cell performance by adjusting feed rate. When the feed rate is 0.24 mL min−1 and 0.6 mL min−1, the best cell performance is obtained at 8M and 4M, respectively.

The cover picture shows a schematic illustration of an ammonia-fueled solid oxide fuel cell stack. The supplied ammonia fuel is first decomposed into hydrogen and nitrogen in the Ni-YSZ porous anode and then the produced hydrogen electrochemically reacts with oxide ion to generate electric power. The stack consists of 30 anode-supported planar cells with an active area of 95 cm2. The output power of over 1 kW and 1,000 h durability have been achieved.

Abstract Several studies relying on the improvements to the important oxygen reduction reaction (ORR) activity for increasing the performance of fuel cells have been reported. However, the application of catalyst conditions used for realizing the excellent activity in a half‐cell to a single‐cell does not guarantee the translation of the excellent performance. Therefore, we investigated the performance characteristics of various types of commercially available catalysts, including alloy catalysts, and compared the trends between the half‐cells and single‐cells using linear scan voltammetry (LSV), polarization curves (IVP), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) measurements. Furthermore, regression analysis was performed to identify the influential factors for examining the complex relationship between the half‐cell and single‐cell performance parameters. The study reveals, that it is highly challenging to express the performances of the catalyst and single‐cell using isolated factors. Additionally, even though the measured activity of the catalyst in a half‐cell is higher than that in the other half‐cells, the difference does not manifest significantly in the single‐cell when the conditions required for its activity are not optimized, indicating that the overall performance of the fuel cell membrane electrode assembly (MEA) is not determined solely by the catalyst.

Abstract In this study, the behavior of an electrochemical hydrogen compressor (EHC) able to compress hydrogen up to 32 bar was investigated. The current density distribution along the EHC was measured using a segmented cell. It was found to decrease from 0.75 A cm−2 to 0.65 A cm−2 along the EHC when using Nafion 117 and when high relative humidity hydrogen was fed to the EHC (at 0.66 A cm−2 and 0.36 V). This drop corresponded to a decrease of the relative humidity of the hydrogen flow from 90 to 55% along the gas channels at the anode side, evidencing the local dehydration of the PEM due to the unbalanced water transport across the membrane. As a consequence, the membrane resistance increased, thus a higher voltage had to be supplied to the EHC in order to maintain good performances, decreasing the overall efficiency. On the other hand, unstable operating conditions were observed when using hydrogen with a low relative humidity.A pseudo‐2D model was developed along with experimental studies to estimate the physical parameters enhancing the efficiency of the EHC. A higher efficiency was obtained when using a thinner membrane than Nafion 117 (53% vs. 37%, at 60 °C and 0.66 A cm−2).

Abstract A novel cathode material of (Nd0.9La0.1)1.6Sr0.4Ni0.75Cu0.25O3.8 (NLSNC4), is synthesized by solid state reaction and is further investigated in combination with samarium doped ceria (SDC) as composite cathodes including 0, 10, 30, 50, and 70 of SDC electrolyte phase. The X‐ray diffraction analysis showed that NLSNC4 was produced in pure phase and was chemically compatible with SDC electrolyte. Electrical conductivities of single phase and composite cathode materials along with their electrochemical performances on SDC electrolytes in symmetric cells were measured by DC four‐probe method and electrochemical impedance spectroscopy (EIS), respectively. Results indicated that the maximum electrical conductivity is 135.56 S cm−1 at 350 °C, measured for single phase NLSNC4, sintered at 1,300 °C. Polarization resistance of pure NLSNC4 cathode was 2.71 Ω cm2 at 800 °C, and NLSNC4‐x wt.% SDC composite cathodes displayed Rp value of 0.35, 0.14, 0.12, and 0.32 Ω cm2 at 800 °C, for x = 10, 30, 50, and 70, respectively.

Fuel CellsVolume 19, Issue 4 p. 309-309 Cover PictureFree Access Cover Fuel Cells 4/2019 First published: 19 August 2019 https://doi.org/10.1002/fuce.201970041AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Graphical Abstract In the framework of the annual conference series, organized by the European Fuel Cell Forum (www.efcf.com), EFCF2018 covered the 13th European Solid Oxide Fuel Cell & Solid Oxide Electrolyzer Forum chaired by Prof. Ellen Ivers-Tiffée and Dr. André Weber, Karlsruhe Institute of Technology, Germany. Traditionally located in Lucerne, Switzerland, the conference welcomed 440 participants from more than 30 countries representing 6 continents. The conference demonstrated the progress in solid oxide technologies on different levels ranging from fundamental studies to commercial systems. Science and technology of solid oxide materials, devices, systems and products, including their wide range of potential applications were intensively discussed. Besides the classical fuel cell and electrolyzers applications also further solid oxide membrane reactors are presented in gas and energy transformation processes. This special issue comprises papers selected from the 280 presentations given by researcher from universities, research centers and industry at the conference. The papers reflect the growing importance of SOFC and SOE systems. Next to papers in the field of novel materials and fabrication processes, the focus is on design and the resulting performance and lifetime of stacks and systems. Volume19, Issue4Special Issue: 13th European SOFC & SOE ForumAugust 2019Pages 309-309 RelatedInformation