bluuebunny/crossref_metadata_2025_split huggingface dataset:
Framework for Analysis of Irreversible Fuel Cell Heat Engine Hybrids
Authors: Williams Mark C. , Gemmen Randall , Gerdes Kirk 
Published: February 2020

A thermodynamic and electrochemical framework for the analysis of the degrading fuel cell heat engine hybrid is developed and explored for various working reactions. Fuel cell hybrids are a combination of energy conversion sub-systems – fuel cells and heat engines. Fuel cell hybrids are important for the future for they are the most efficient devices when converting chemical energy of methane from natural gas and renewable fuels to electricity. While the perfect fuel cell would undergo no degradation, practical fuel cells with irreversibilities will degrade. The common practice is to linearize degradation. However, experimental evidence shows that ASR(t) is commonly an ohmic parabolic function. By the principle of superposition one can easily develop the equations for degrading hybrids from those developed for hybrids. The path of maximum power can be developed for degrading hybrids as a function of ASR and temperature. The maximum power for a degrading fuel cell hybrid is given by the Gaussian hypergeometric function. The range of the operation of the SOFC is likely most conducive to hybrid operation for hydrogen oxidation as the working reaction. Each working reaction has a characteristic transition temperature and a characteristic optimal operating temperature.
Enhancing Performance of Stabilized Bismuth Oxide-Based Cathodes via Infiltration Process for LT-SOFCs
Authors: Park Jin Wan , Yun Byeong Hyeon , Joh Dong Woo , Lee Kang Taek 
Published: February 2020

Solid oxide fuel cells (SOFCs) are the most efficient technology to directly convert chemical energy to electrical energy via electrochemical reactions. However, commercialization of SOFCs has been impeded due to the high cost associated with high temperature operation over 800 oC with conventional stabilized zirconia electrolytes. Thus, lowering the temperature of solid oxide fuel cells (SOFCs) is essential for the commercialization via availability to use cheap stainless steel interconnector, rapid start-up time, and higher mechanical and chemical stability, leading to significant reduction of system cost. To achieve this goal, at reduced temperatures the cathodic polarization mainly caused by oxygen reduction reaction at triple phase boundaries (TPBs) should be effectively reduced.
At lower temperatures below 700 oC, however, the cathode polarization exponentially increases due to its thermally activated nature, thus dramatically decreasing the performance. Previously, stabilized bismuth oxide-based composite cathodes (ex: LSM-ESB) have been reported as promising cathodes for LT-SOFC applications with their low area specific resistance (ASR) at LT region. This high performance would be explained that LSM has low activation energy for dissociative adsorption of oxygen in ORR on its surface and that ESB has exceptionally high ionic conductivity as well as excellent surface exchange properties. Therefore, one can expect that the microstructural optimization of these cathode could further increase the cathode performance as well as enhance the their durability.
In this study, we employed the infiltration process to tailor the surface morphologies of stabilized bismuth oxide-based composite cathodes for enhancing surface activity and their stability to achieve higher SOFC performance. Through infiltration, for example, LSM was infiltrated on the porous ESB scaffold with different manners. The microstructural evolution and electrochemical performance was characterized and their cross-effect will be discussed.
Dependence of Electrical Properties on Thermal Reduction of Protecting Oxides for SOFC Interconnect Applications
Authors: Tsai Shu-Yi , Fung Kuan-Zong , Ni Chung-Ta , Ho Hsin-Chia 
Published: February 2020

In this study, plasma sprayed (Mn,Co)3O4 (MCO) coatings with spinel structure are used to form protective layer for metallic interconnects of solid oxide fuel cells.
The temperature during thermal spraying is high enough to change the crystal structure and conductivity of protective oxides. The structure change is caused by the removal of oxygen ions at higher temperature. This behavior is so-called thermal reduction. Furthermore, the transformation of MCO Spinel to a NaCl-type structure causes the degradation in its conductivity by several orders of magnitude. With better understanding and control of thermal reduction and/or phase transformation, it is believed that the proper heat treatment is an adequate method to obtain desired properties for protective oxide.
Thus, the objective of this study is (1) to investigate the influence of thermal reduction on the conductivity and crystal structure; (2) to improve the performance of interconnect through proper annealing at desired temperatures. XRD, SEM, and impedance spectroscopy are used to characterize the protective oxides before and after annealing and thermal reduction.
Hydrogen Generation Via Sodium Borohydride Hydrolysis Using the Graphene Supported Platinum-Ruthenium-Cobalt Catalysts Prepared By Microwave-Assisted Synthesis
Authors: Semasko Miroslav , Tamasauskaite-Tamasiunaite Loreta , Stalnioniene Irena , Zieliene Albina , Vaiciuniene Jurate , Simkunaite-Stanyniene Birute , Selskis Algirdas , Norkus Eugenijus 
Published: February 2020

Sodium borohydride is of interest as a source for a hydrogen generation during its catalytic hydrolysis. Various catalysts have been developed for this purpose. In the present study the graphene supported platinum-ruthenium-cobalt catalysts (denoted as PtRuCo/GR) with the different Pt:Ru:Co molar ratios, prepared by means of microwave-assisted synthesis, were used as catalysts towards hydrogen generation via sodium borohydride hydrolysis. The morphology and composition of catalysts were examined using Field Emission Scanning Electron Microscopy and Inductively Coupled Plasma Optical Emission Spectroscopy. Catalytic activity of PtRuCo/GR with the different Pt:Ru:Co molar ratios was determined by measuring the amount of hydrogen generated directly from aqueous alkaline solutions of sodium borohydride and compared with that of Co/GR. The data on hydrogen generation volume with respect to time at different concentrations of sodium borohydride and different temperatures have been presented.
It has been determined that the PtRuCo/GR catalysts were synthesized with the Pt:Ru:Co molar ratios equal to 1:2:2, 1:1.7:5.6 and 3.5:1:23. The EDX spectra confirm the presence of Pt, Co and Ru nanoparticles in the investigated PtCoRu/GR catalysts.
It was found that the temperature and composition of catalysts have exceptional influence on the rate of hydrogen generation from alkaline sodium borohydride solutions. Significantly greater hydrogen generation rate is obtained at the synthesized PtRuCo/GR catalysts as compared with that at Co/GR. Highest rates of hydrogen generation were obtained at 60 oC and are 207.5, 82.8 and 53.1 L min-1 gMtotal
-1 for the PtRuCo/GR catalysts with the Pt:Ru:Co molar ratios equal to 1:2:2, 1:1.7:5.6 and 3.5:1:23, respectively. The activation energy (E
a), determined from the kinetic data, is 45.6, 55.9 and 50.2 kJ mol-1 for PtRuCo/GR with the above mentioned Pt:Ru:Co molar ratios, indicating a high catalytic activity of the synthesized catalysts towards hydrolysis of sodium borohydride.
Neutron Radiography of PEM Water Electrolysis Cells
Authors: Seweryn Jakub , Biesdorf Johannes , Boillat Pierre , Schmidt Thomas J. 
Published: February 2020

In the past neutron radiography has been successfully applied to investigate the water transport behavior in polymer electrolyte fuel cells and its influence on overall cell performance [1-2]. The same technique can be also used to visualize the gas and water transport inside working polymer electrolyte membrane (PEM) electrolyzers.
While it is obvious that under operating conditions, a two phase flow of water and its gaseous splitting products occurs inside the porous layers and the flow channels, it is not clear to what extent this can influence overall electrolysis cell performance. In theory gas bubble formation can block the catalyst surface on the anode, decreasing the overall efficiency In addition, the resulting inhomogeneity of the current density over the active area can lead to a local overheating and membrane damage. Strong attenuation of the neutron beam inside liquid water, as compared to typical electrolyzer materials like steel and titanium, makes neutron radiography a perfect technique to investigate these phenomena.
Neutron radiograms of PEM electrolysis cells (1 cm2 active area) were obtained at varying working parameters. Our experimental setup is designed to provide maximal imaging capabilities at simulated local conditions which can occur in real scale devices. Special attention will be put to the water – gas transport perpendicular to the porous layer. Figure 1 shows the typical patterns with gradients of water thickness being little dependent on the operating conditions.
This presentation is intended to provide the fundamentals about both the experimental possibilities as well as the water/gas transport behavior during PEM electrolysis cell operation, stimulating the development of numerical models describing this complex system.

References

[1] P. Boillat, P. Oberholzer, A. Kaestner, R. Siegrist, E. H. Lehmann, G. G. Scherer and A. Wokaun, J. Electrochem. Soc.
159, F210-F218 (2012).
[2] P. Boillat, G. Frei, E.H. Lehmann, G.G. Scherer, A. Wokaun, Electrochem. Solid-State Lett.
13(3), B25-B27 (2010).

Figure 1. Image recorded for the dry cell (section A) and the cell with flooded anode (section B). The difference in horizontal and vertical scales results from the use of a tilted detector setup [1].
Section C shows images of cells taken at increasing current density (denoted in bottom - right corner [A cm-2]) with the same configuration as in section A and B. The pixel values have been divided by reference values of the cell with flooded anode – white pixels on anode side corresponds to gas, while black on the cathode side to water.

Figure 1
Redox Flow Battery Membranes with Improved Vanadium-Ion Barrier Properties
Authors: Gubler Lorenz , Nibel Olga , Bonorand Lukas , Schmidt Thomas J. 
Published: February 2020

The crossover of active redox species in flow batteries leads to a decrease in the faradaic efficiency and, in case of cells with different species on the positive and negative side, to cross-contamination of the electrolyte solutions. In the all-vanadium redox flow battery (VRB) typically vanadium sulfate in a background electrolyte of sulfuric acid is used as electrolyte. In case of commonly used proton exchange membranes, vanadium species can pass through the electrolyte more or less easily.
In this contribution, an approach to improve the vanadium-ion barrier properties of a membrane is presented, while largely maintaining its area resistance [1]. Ethylene tetrafluoroethylene (ETFE) films of 25 µm thickness were grafted with styrene and acrylonitrile (AN) using the radiation-induced grafting technique. Subsequently, the grafted AN units were amidoximated using hydroxylamine. Amidoxime groups are metal-ion complexing agents. The styrene units were sulfonated to introduce cation exchange sites. The composition of the obtained membranes was analyzed by FT-IR spectroscopy and the elemental distribution by energy-dispersive x-ray spectroscopy (EDX) coupled with scanning electron microscopy (SEM). The key properties of the membranes for the application in the redox flow cell, i.e., vanadium ion permeability and area resistance, were investigated. It was found that the permeability of vanadium ions was effectively reduced by increasing the amount of amidoxime groups in the membrane, while the area resistance, measured in a redox flow cell setup, did not considerably increase.
In this contribution, the key polymer design aspects to tune the ohmic resistance and vanadium barrier properties of the membrane are highlighted, relevant ex situproperties of membranes discussed, and redox cell test data presented to demonstrate the features of the grafted amidoxime membranes compared to Nafion 212.
[1] L. Gubler, O. Nibel, L. Bonorand, European Patent Application EP15154151, Paul Scherrer Institut, 2015

Figure 1
Localised Electrochemical Impedance Measurement Using an Innovative Reference Electrode Array
Authors: Brightman Edward , Engebretsen Erik , Lyu Chao , Hinds Gareth 
Published: February 2020

Electrochemical impedance spectroscopy (EIS) is an increasingly popular diagnostic tool for polymer electrolyte membrane fuel cells (PEMFCs) and other electrochemical energy conversion devices. Data are commonly fitted to an equivalent circuit model enabling empirical determination of overpotentials, double layer capacitance, and other key parameters. However, conventional experimental configurations are limited to two-electrode measurements, which rely on the assumption that the anode contribution to impedance is negligible. An additional limitation is that an average response for the whole cell is obtained, whereas it is generally accepted that local inhomogeneity in reactant concentration, water distribution and catalyst utilisation is a significant factor affecting fuel cell durability. The use of segmented cells to obtain a functional map of fuel cell performance is well established, but their application to impedance spectroscopy requires complicated equipment and expensive hardware.
Here we report the first localised EIS measurements in a single cell PEMFC using an innovative reference electrode array developed at NPL. By making contact directly with the electrode of interest using a Nafion tube salt bridge inserted through the end plates of the cell, the NPL reference electrode gives an iR-free, localised potential measurement, with the advantage that commercial MEAs can be tested directly with minimal modification to cell hardware. An array of reference electrodes is used to measure the spatial variation in impedance across the active area of the cell under a range of operating conditions, before and after accelerated aging of a commercial MEA. The advantages and disadvantages of this technique and the implications for modelling and optimisation of fuel cell design are discussed.
Use of Hybrid Cathodes to Reduce Platinum Content in High Temperature Proton Exchange Membrane Fuel Cells (HT-PEMFCs)
Authors: Pavlicek Ryan , Strickland Kara , Mukerjee Sanjeev 
Published: February 2020

An investigation into the development and use of hybrid cathodes in high temperature proton exchange membrane fuel cells was undertaken. Previously, non-pgm materials had been developed for use as oxygen reduction catalysts in proton exchange membrane fuel cells[1, 2]. Compared to platinum, long term durability of these non-pgm materials at the elevated temperatures associated with high temperature fuel cells is negatively impacted by the low active site density. In this work, these non-pgm materials are combined with low platinum loadings in order to take advantage of the high activity of the non-pgms as well as the high active site density of platinum. This reduction of platinum content allows for a drastic reduction in the price of membrane electrode assemblies (MEAs). Additionally, these non-pgm materials have shown very high tolerance towards phosphate poisoning (Figure 1) when compared to platinum[3]. Hybrid cathodes were fabricated and used in conjunction with proprietary membranes (TPS Membrane, Advent Technologies) and operated between 160°C and 180°C in order to evaluate performance and stability.

Acknowledgment:
The authors gratefully acknowledge the financial support from the Department of Energy-Energy Efficiency and Renewable Energy, Fuel Cell Technology Office under an Incubator grant (DE-EE0006965). Use of the Stanford Synchrotron Radiation Light source, SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515. Use of Beamline 2-2 at SSRL was partially supported by the National Synchrotron Light Source II, Brookhaven National Laboratory, under U.S. Department of Energy Contract No. DE-SC0012704. Use of the beamline 9-BM in Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357. MRCAT operations are supported by the Department of Energy and the MRCAT member institutions. This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.
References
1. Strickland, K., et al., Highly active oxygen reduction non-platinum group metal electrocatalyst without direct metal-nitrogen coordination. Nat Commun, 2015. 6.
2. Serov, A., K. Artyushkova, and P. Atanassov, Fe-N-C Oxygen Reduction Fuel Cell Catalyst Derived from Carbendazim: Synthesis, Structure, and Reactivity. Advanced Energy Materials, 2014. 4(10): p. n/a-n/a.
3. He, Q., et al., Mitigating Phosphate Anion Poisoning of Cathodic Pt/C Catalysts in Phosphoric Acid Fuel Cells. The Journal of Physical Chemistry C, 2013. 117(10): p. 4877-4887.

Figure 1
Single-Ion-Conducting Glass-Polymer Hybrid Electrolytes for Lithium Batteries
Authors: Villaluenga Irune , Wujcik Kevin , Tong Wei , Devaux Didier , Wong Dominica H.C. , DeSimone Joseph M. , Balsara Nitash P 
Published: February 2020

Electrolytes used in lithium-ion batteries that power personal electronic devices and electric vehicles comprise lithium salts dissolved in flammable organic liquids. Catastrophic battery failure often begins with the electrolyte decomposition and combustion. Mixtures of liquids and salts have additional limitations. The passage of current results in an accumulation of salt in the vicinity of one electrode and depletion close to the other electrode, because only the cation participates in the electrochemical reactions. These effects are minimized in the case of single-ion-conducting-solid electrolytes due to the absent of concentration polarization and the limited solubility and slow diffusion (1). Therefore, non-flammable single-ion-conducting solid electrolytes have the potential to dramatically improve safety and performance of lithium batteries (2,3). Solid electrolytes such as inorganic sulfide glasses (Li2S–P2S5) are single-ion-conductors with high shear moduli (18-25 GPa) and high ionic conductivity (over 10−4S/cm) at room temperature (4,5). However, these materials, on their own, cannot serve as efficient electrolytes as they cannot adhere to moving boundaries of the active particles in the battery electrode as they are charged and discharged.
In this study, we describe hybrid single-ion-conducting electrolytes based on inorganic sulfide glasses and perfluoropolyether polymers for lithium batteries. Herein, it is demonstrated that hybrid electrolytes provide a compelling alternative to the traditional glass, ceramic, or polymer battery electrolytes. These electrolytes present high transference numbers, unprecedented ionic conductivities at room temperature, excellent electrochemical stability, and limit the dissolution of lithium polysulfides. The results in this work represent a significant step toward addressing the challenges of enabling the next generation cathodes such as lithium nickel manganese cobalt oxide and sulfur.
_______________________
[1] J.M. Tarascon, M. Armand, Nature, 414 (2001) 359-367.
[2] R. Bouchet, et al., Nature Materials, 12 (2013) 452-457.
[3] N. Kamaya, et al., Nature Materials, 10 (2011) 682-686.
[4] Z. Liu, et al., Journal of the American Chemical Society, 135 (2013) 975-978.
[5] A. Sakuda, A. Hayashi, Y. Takigawa, K. Higashi, M. Tatsumisago, Journal of the Ceramic Society of Japan, 121 (2013) 946-949.
Thermal Analysis and Modeling of an Ultracapacitor Module
Authors: Koo Boram , Park Sung June , Yi Jaeshin , Shin Chee Burm , Choi Jongrak , Lee Ha-Young 
Published: February 2020

Electricity generated from renewable sources such as wind and solar power is intermittent. Electrical energy storage devices are therefore critical for effectively leveling the intermittent nature of renewable energy sources. Ultracapacitors (UCs), also known as supercapacitors, have the potential to meet the power requirements for the grid-scale renewable energy storage systems. As compared to batteries, UCs offer a higher power density, higher efficiency, and longer shelf and cycle life. Because the performance of UC depends on temperature, it is important to calculate accurately the thermal behaviors of an individual UC cell in the module composed of multiple UC cells for the efficient and reliable systems integration of UC in grid applications.
In this work, modeling is performed to study the thermal behaviors of the module composed of 18 UC cells. The thermal behaviors of the ultracapacitor cells in the module are measured during the charge/discharge cycling of the ultracapacitor module with constant-current. The charge/discharge current values examined are 50, 100, 150, and 200 A. The validation of the modeling approach is provided through the comparison of the modeling results with the experimental measurements.
Fig. 1 shows the schematic diagram of the ultracapacitor module composed of the 18 ultracapacitor cells (3.7V/3000F) from LS Mtron Ltd. (Anyang, Republic of Korea). The red dots with numbers in Fig. 1 indicate the positions for thermocouple measurement. In Fig. 2, the variations of surface temperature with time from the modeling are compared with those from the experiment during the charge-discharge cycles with the constant current of 200 A. The modeling results shown in Fig. 2 are in good agreement with the experimental measurements.

Figure 1
Synthesis and Characterization of Cross-Linked Anion Exchange Membrane Materials Based on Poly(p-phenylene)s for Redox Flow Battery Applications
Authors: Lee Jang Yong , Cha Min Suc , Kim Tae-Ho , Yoon Sangjun , Hong Young Taik 
Published: February 2020

Recently, the most commonly used membrane in vanadium redox flow battery(VRFB) are ion exchange membrane, especially, cation exchange membrane. The state-of-the-art perfluorosulfonic acid polymers, Nation®, are widely used because of their outstanding ion conductivity and chemical stability. However, high cost and vanadium crossover have limited the commercialization of VRFB technology.
Dislike cation exchange membrane, anion exchange membrane has been widely investigated because it could fundamentally decrease permeability of vanadium ions. Nevertheless, the high level of difficulty and low mechanical property have been considered as major obstacles to the practical use of AEM in RFB applications.
In this study, we synthesized hydrocarbon-based AEM materials by Ni(0)-catalyzed coupling polymerization. In addition, synthesized polymers were simply crosslinked by diamine-based cross-linker in order to improve their physical property. We have investigated their physical properties, vanadium crossover and VRFB performance.