bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Synthesis of Hydrogen with Depolarization of the Anodic Process
Authors: Skatkov Leonid , Tulskiy Gennadiy , Tulskaya Alena , Bayrachniy Vladimir , Gomozov Valeriy , Deribo Svetlana 
Published: February 2020

World experience defines hydrogen as the most perspective energy carrier. Producing hydrogen by electrolysis helps effectively solve the problem of peak loads and failures arising from the different structure of energy consumption during the day .
Thermoelectrochemical cycles of producing hydrogen are intensively studied in Kharkov Polytechnic Institute, Kharkov, Ukraine. Further development of hydrogen production by electrolysis of water associated with implementation of Hybrid Sulfur cycle or "Westinghouse cycle") [1]. It is a two–step process, first a low–temperature electrochemical step (1):
2H2O + SO2 H2 + H2SO4 (1)
and second a high temperature (2):
H2SO4 H2O + SO2 + 0,5 O2 (2)
The clear advantage of the Hybrid Sulfur Cycle process is that the standard reversible voltage E0 of the net cell reaction (2) is only 0.17 V. For comparison, conventional water electrolysis requires E0 = 1.23 V. In laboratory–scale tests, the realized cell voltage of SO2 depolarization electrolysis has been 0.5¼1.3 V, depending on the current density and other operational parameters compared with the 1.8¼2.0 V of commercial alkaline water electrolysis. Thus, SO2 depolarization electrolysis would require 25¼60 % of the electrical energy required for direct water splitting by conventional electrolysis. The electrochemical process is far from technical implementation and intensively studied in recent years.Hybrid Sulfur cycle was intensively studied for practical implementation with using platinum, gold and palladium anodes . Further investigation is connected with using more affordable anode materials. According to the E–pH diagram, ruthenium, molybdenum, tungsten and their oxides are defined to be most perspective catalytic materials.
Active porous anode was obtained by covering the graphite basis by active carbon, Pt, MoO3, RuO2, WO3. Covering with active carbon was prepared by impregnating the graphite basis in sugar solution, followed by drying and thermal decomposition. The other composite coatings were prepared by impregnating a sugar solution and brine H2[PtCl6], (NH4)6Mo7O24·4H2O, (NH4)4W5O17, followed by drying and thermal decomposition at 600...650 K. The cylindrical anodes have diameter 20 mm and thickness 5 mm.
They were inserted into a special current source, consisting of a current–conducting tubes with welded sample holder (Fig. 1). Samples were fixed in a holder nut. Current supply material – titanium coated PTFE. Current–voltage measurements were carried out in plastic cell with anode and cathode separation space cation exchange membrane. Electrode potentials were measured relative to a mercury sulfate reference electrode and converted to the normal hydrogen electrode.
Nanostructured Nickel Iron Sulfide Grown on Nickel Foam for Highly Active and Durable Water Splitting Electrocatalyst in Alkaline Electrolyte
Authors: Shanmugam Sangaraju , Ganesan Pandian 
Published: February 2020

The increasing demand for the energy and environmental concerns has induced global efforts to find and explore alternative energy sources for fossil fuels. As an ideal candidate, hydrogen produced from water splitting is an attractive next generation energy conversion device [1]. The noble metals are the most active in catalyzing the water electrolysis to produce pure hydrogen, but the high cost and elemental scarcity greatly hinder their widespread applications. The development of low-cost, efficient, and robust electro-catalysts (both oxygen evolution (OER) and hydrogen evolution (HER) catalysts) for water splitting is a crucial step toward the conversion and storage of sustainable energy resources such as solar energy. Not only the catalysts need to be composed of inexpensive elements, they are also desirable to be prepared at low energy cost [2,3,4].
Here, we have investigated the inexpensive synthesis of electrochemically depositing the nickel iron sulfides on nickel foam for the highly efficient bi-functional water splitting to meet the current demand. Nickel iron sulfide on nickel foam (NiFeS/NF) showing the low over-potential about 230 mV for OER and 205 mV for the HER. This bi-functional catalyst also showing robust durability about 200 hours. The high performance and also the facile synthesis with strong coating on nickel foam make it commercial viable catalyst. The NiFeS/NF catalyst for large scale with highly efficient and durable bi-functional catalyst for water splitting outperform the noble metals such as IrO2, RuO2electrocatalysts. The details of direct synthesis, characterization of new transition metal sulfides on metallic substrates will be discussed in this presentation.

References:

[1] N. Jiang, L. Bogoev, M. Popova, S. Gul, J. Yanob, Y. Sun, J. Mater. Chem. A, 2014, 2,19407–19414.
[2] P. Ganesan, M. Prabu, J. Sanetuntikul, S. Shanmugam, ACS Catal., 2015, 5, 3625-3637.
[3] X. Long, G. Li, Z. Wang, H. Y. Zhu, T. Zhang, S. Xiao, W. Guo, S. Yang, J. Am. Chem. Soc.
2015, 137, 11900−11903.
[4] C. Tang, Z. Pu, Q. Liu, A. M. Asiri, X. Sun, Electrochimica Acta. 2015, 153, 508–514
Catalysts, Nickel Phosphide (Cathodic) and LiCoO2 (Anodic), for Electrolysis of Water
Authors: Hwang Shinjae , Porter Spencer H , Laursen Anders B. , Gardner Graeme , Li Mengjun , Manichev Viacheslav , Amarasinghe Voshadhi , Taghaddos Elaheh , Safari Ahmad , Greenblatt Martha , Garfunkel Eric , Dismukes Gerard Charles 
Published: February 2020

Choice catalysts are required to lower the activation barriers for both the oxidative and reductive half reactions associated with electrolysis of water. Using models provided by natural systems, such as the Ca-Mn cubane motif in the water oxidizing complex of photosystem II and the Ni-S active site of hydrogenase, we have developed LiMO2 (M = Transition metal) 1 and Ni-P compounds which mimic their chemistry2. Thin films of the oxygen evolving reaction (OER) catalyst, cubic LiMO2 (M = Co), and the hydrogen evolving reaction (HER) catalyst, NixPy, are a potentially cost-effective and electrically efficient catalysts for water splitting. Thin films of both the OER and HER catalysts on a transparent conductive oxide substrate and on a light absorbing substrate [Si (100)] have been produced. We shall report the structural, surface, and atomic characterization of these films via x-ray photoelectron spectroscopy, atomic force microscopy, helium ion microscopy, x-ray diffraction, and Rutherford backscattering. These results aid in explaining the (photo-)electro-catalytic properties observed. The cathode and anode can be combined to create a monolithic device that splits water and is discussed in a complementary talk in section I07 titled: “Efficient Solar Water Splitting via Tunable Photoanode-Photocathode-Catalyst Interface Devices”.
References

Gardner, G. P.; Go, Y. B.; Robinson, D. M.; Smith, P. F.; Hadermann, J.; Abakumov, A.; Greenblatt, M.; Dismukes, G. C. Angew. Chem. Int. Ed.
2012, 51, 1616.

Laursen, A. B.; Patraju, K. R.; Whitaker, M. J.; Retuerto, M.; Sarkar, T.; Yao, N.; Ramanujachary, K. V.; Greenblatt, M.; Dismukes, G. C. Energy Environ. Sci.
2015, 8 (3), 1027.

Figure 1
Conditions Causing Edge Corrosion in Flow-Battery Stacks
Authors: Darling Robert M. , Shiau Huai-Suen , Weber Adam Z , Perry Mike L. 
Published: February 2020

Conventional redox-flow batteries (RFBs), like all-vanadium, contain reactors with many individual cells stacked in series electrically and in parallel fluidically. Because the positive and negative electrolytes are conductive (> 10 S/m), shunt currents flow in the fluidic manifolds connecting the individual cells. This is a long recognized source of inefficiency in RFBs and in some fuel-cell [1, 2] and electrolyzer [3] stacks with circulating liquid electrolytes. These undesirable shunt currents are typically managed by designing the manifold and port regions of the cell stacks to have large enough resistances to yield acceptable efficiency without causing excessive pressure drop [1, 4]. Equivalent-circuit models with resistor elements for the manifold and port are normally used to model the shunt and port currents when analyzing these tradeoffs (e.g., [2, 5]).
Considerably less attention has been paid to the electrochemical reactions that support the shunt currents. For example, at the positive electrodes at the positive end of an all-vanadium RFB cell stack at open circuit, V(V) is discharged to V(IV) in the active area (drain current), while V(IV) is converted to V(V) in the vicinity of the port to support the shunt current. The simultaneous occurrence of the V(IV)/V(V) reaction in the anodic and cathodic directions on the same electrode leads to interesting potential and current profiles. More importantly, it is possible to develop large overpotentials at the junction between the edge of the electrically-conductive bipolar plate and the insulating port region that can cause deleterious reactions like carbon corrosion.
In this talk, steady-state and transient numerical simulations of an all-vanadium RFB stack with two cells will be presented. The impact of the port and manifold resistances on the overpotential at the junction between the more positive bipolar plate and the adjacent insulating port will be discussed. Figure 1 shows a nonlinear relationship between port resistance and overpotential at the junction. High overpotentials, probably sufficient to cause carbon corrosion, are observed when the port resistance is low. The governing relationships and design criteria will be introduced.
References

C. Reiser, U.S. Patent 3,634,139 (1972).

M. Katz, J. Electrochem. Soc., 125, 515 (1978).

I. Rousar, J. Electrochem. Soc., 116, 676 (1969).

Q. Ye, J. Hu, P. Cheng, and Z. Ma, J. Power Sources,
296, 352 (2015).

E. A. Kaminski and R. F. Savinell, J. Electrochem. Soc., 130, 1103 (1983).

Figure 1
Effect of Ti(IV) Ion on Mn(III) Stability in Ti/Mn Electrolyte for Redox Flow Battery
Authors: Kaku Hirokazu , Dong Yong-Rong , Hanafusa Kei , Moriuchi Kiyoaki , Shigematsu Toshio 
Published: February 2020

Renewable energies such as wind power and solar power are now rapidly introduced worldwide. Energy storage systems, especially large-scale batteries become more necessary than ever for stabilizing the electric power fluctuations caused by renewable energies. Redox flow battery (RFB) is one of the strong candidates for this application, because of its easiness to scaling up and monitoring of state of charge, long cycle life, and safety. To accelerate the commercialization of RFB, reducing the cost of the battery system is one of the most important issues.
Nowadays, vanadium (V) electrolyte is generally utilized for commercial RFB. Because the electrolyte is one of the key and expensive components in RFB system, many alternative electrolytes are developed to decrease the cost of RFB system. We have investigated various metal ions as active materials that are abundant and common for industrial use. In our research, titanium/manganese (Ti/Mn) RFB system has good potential, which use the redox reactions of Mn2+/Mn3+ and Ti4+/Ti3+ as positive and negative side, respectively. We have already reported that the cell voltage and the energy density of Ti/Mn system are comparable to those of V system [1].
One of the challenges in Ti/Mn system is to improve the stability of Mn3+ ion in the positive electrolyte at charged state. Mn3+ ion can easily disproportionate to Mn2+ and MnO2, which leads to degradation of battery performance due to the precipitation of MnO2 particles. We reported that mixing Ti4+ ion in the positive electrolyte makes redox reaction of Mn2+/Mn3+ more reversible and prevents the precipitation of MnO2 particles. Ti4+ ion in the positive electrolyte also changes the color of the electrolyte with Mn2+ ion and the potential of positive electrolyte during charging, which strongly suggests the Ti4+ion interacts with Mn ion.
This time we investigated the effect of Ti4+ ion in the positive electrolyte with various ratios of Ti to Mn. The effect of the ratio of Ti4+ ion on the electrochemical properties and MnO2 morphologies will be closely discussed.
References
[1] Y. R. Dong, et.al., 228th ECS Meeting, 120 (2015)
The Advantages of the Use of Porous Metal Fiber Media in Different Alloys As Gas Diffusion Layer in Various Energy Storage Systems
Authors: Goossens Davy , Synhaeve Kris , De Baerdemaeker Jérémie 
Published: February 2020

Large scale energy storage systems are a possible alternative to buffer the variability and the intermittency of electricity generated from renewable sources such as solar and wind. The main requirements of such energy storage systems are high efficiency, good rate capability, long life and low cost.
The electrodes in these large energy storage systems like e.g. Electrolysers and Redox Flow batteries are becoming more and more important attributers to the cost and performance drivers in the BOP. As the working environment in the different available system vary significantly, an optimization of the structure and material use in the electrodes is clearly needed.
In this study, different metal fiber media which can be used as porous electrode, produced in a variety of different metals and structures were evaluated on the performance drivers needed to achieve an improved energy storage system. The different materials are compared with alternative technologies on a variety of parameters like corrosion resistance, conductivity, permeability, mechanical strength, … and evaluated on the performance in an electrochemical cell.
This talk will give an overview on the progress of each of the different drivers.
Cr Poisoning of (La,Sr)(Co,Fe)O3 SOFC Cathodes at the Micrometre to Nanometre Scale
Authors: Ni Na , Skinner Stephen J. , Jiang San Ping , Wang Cheng Cheng 
Published: February 2020

For developing solid oxide fuel cells (SOFCs) operating at intermediate temperatures, metallic materials have become a preferential choice for the interconnect due to their low cost and excellent physical and chemical properties. However the presence of chromium in all commonly used metallic alloys has been found to cause poisoning of the cathode leading to rapid electrochemical performance degradation of the cathodes including one of the most promising (La,Sr)(Co,Fe)O3-δ (LSCF) perovskite oxides [1-4]. Despite the extensive research on the chromium deposition and poisoning processes, careful microstructural studies at multi-scale lengths are rare, which can provide valuable information for the fundamental understanding of the Cr poisoning mechanisms required for developing Cr tolerant cathode materials.
In this paper, we examine the Cr poisoning mechanisms in LSCF materials by correlating the bulk electrochemical properties of the cell with their structural and chemical change at multi-scales down to the nanometer level. Cells with LSCF cathodes were prepared, and the effect of Cr poisoning on the electrochemical behavior of the cell was assessed by electrochemical impedance spectroscopy. The change in nano/microstructure and chemistry due to poisoning were studied in parallel by a combination of several advanced electron microscopy techniques including focus ion beam (FIB) tomography, high resolution and analytical (scanning) transmission electron microscopy ((s)TEM). Our results show that apart from change at the micrometer level, Cr poisoned samples with an increase in the total polarization resistance by one order of magnitude exhibit subtle nanoscale changes such as formation of nanometer size Cr rich phases, Cr segregation at LSCF grain boundaries and alternation of LSCF bulk stoichiometry. This nanoscale evolution correlates well with the impedance results obtained from the same samples, which shows that the area specific resistance of poisoned sample increased due predominantly to the increase of the oxygen reduction component related with a decrease both in the oxygen exchange rate at the LSCF internal surface and the oxygen diffusion in the electrode.

References

[1] M.C. Tucker, H. Kurokawa, C.P. Jacobson, L.C. De Jonghe, S.J. Visco, J. Power Sources
160 (2006) (1) 130.
[2] S.P. Jiang, X.B. Chen, Int. J. Hydrog. Energy
39 (2014) (1) 505.
[3] S.N. Lee, A. Atkinson, J.A. Kilner, J. Electrochem. Soc.
160 (2013) (6) F629.
[4] B. Wei, K. Chen, C.C. Wang, Z. Lü, S.P. Jiang, Solid State Ion.
281 (2015) 29.
Study on Solid Oxide Fuel Cell with Porous Scaffold Electrode Manufactured By Tape Casting Process
Authors: Bae Joongmyeon , Jang Young-hoon 
Published: February 2020

Solid oxide fuel cell (SOFC) is energy conversion device which can converts chemical energy of hydrogen and oxygen to electrical energy. Conventional SOFC is fabricated by preparing anode support and coating electrolyte and cathode by spin coating or screen printing. One alternative way to fabricating SOFC is making porous scaffold on electrolyte support by same material with electrolyte and infiltrating electrode catalyst in porous scaffold. By this procedure, nano-sized catalyst network can be distributed in electrode and microstructure of electrode become easy to control and gas diffusion in electrode can be enhanced. However, conventional scaffold type SOFC has high ohmic resistance because of thick electrolyte support. To enhancing the performance of scaffold type SOFC, electrolyte thickness should be reduced. Moreover, there is problem that connectivity of electrolyte support and porous backbones is increased but porosity of scaffold is decreased as sintering temperature is increased. For solving these problems, tape casting process was applied to fabricate SOFC. By laminating tapes of each layers and co-sintering process, both connectivity and porosity can be obtained in high temperature sintering process.
In this study, performance of scaffold electrode was compared with thick film electrode and SOFC single cell with porous scaffold electrode was fabricated by tape casting process. First, performance of scaffold electrode was compared with thick film electrode by electrochemical impedance spectroscopy analysis. La0.4Sr0.6Ti0.4Mn0.6O3-δ was infiltrated to porous scaffold as electrode catalyst and symmetric cells of scaffold electrode and thick film electrode were prepared. Area specific resistance (ASR) of scaffold electrode was 0.6 Ω·cm2 and ASR of thick film electrode was 3.4 Ω·cm2 at 800℃. SOFC single cell with porous scaffold electrode was fabricated by tape casting process. 8 mol % Yttria-stabilized Zirnocia (8YSZ) was used as electrolyte material. Electrolyte slurry and porous scaffold slurry with pore former were prepared and sequentially casted to make thin electrolyte and anode support. Cathode backbone tape was laminated on the sample by hot pressing. By sintering at 1400℃, thin electrolyte and porous scaffold were fabricated. La0.4Sr0.6Ti0.4Mn0.6O3-δ and La0.8Sr0.2MnO3 were infiltrated as anode catalyst and cathode catalyst, respectively. Open circuit voltage of the sample was 1.09V at 800℃, indicating that thin and dense electrolyte was formed. And the effects of porous scaffold were also investigated with respect to different porosity and different catalyst loading amount.

Figure 1
Simultaneously Coupled Mechanical-Electrochemical-Thermal Simulation of Lithium-Ion Cells
Authors: Santhanagopalan Shriram , Zhang Chao , Sprague Michael A. , Pesaran Ahmad 
Published: February 2020

Understanding the combined electrochemical-thermal and mechanical response of a system has a variety of applications. For instance, such behavior is characterized routinely in reactor design to understand structural failure of components from electrochemical fatigue. In energy storage, the potential induced changes to properties of materials (e.g., swelling or surface oxidation induced fracture) have often been categorized as reliability concerns. For lithium ion batteries, there is the added concern over safety of the system in the event of mechanical failure of the cell components.
In this work, we study different mechanical test conditions and examine the interaction between mechanical failure and electrochemical-thermal responses, by developing a simultaneously coupled model. We begin with a model system to demonstrate the steps involved in building the coupling framework and proceed to model a pouch-format cell with explicit representations for each individual component such as the active material, current collector, separator, etc. Anisotropic constitutive material models are presented to describe the mechanical properties of active materials and separator. Some initial results are shown in Figure 1. The model predicts accurately the force-strain response and fracture of battery structure, simulates the local failure of separator layer, and captures the onset of short circuit for lithium-ion battery cell under different test conditions. The difference in the electrochemical response and the implications for follow on chemical reactions under these test conditions are discussed.
Acknowledgement

This study was supported by Computer Aided Engineering for Batteries (CAEBAT) project of the Vehicle Technologies Office, Office of Energy Efficiency and Renewable Energy, U.S. Department of Energy. The research was performed using computational resources sponsored by the Department of Energy's Office of Energy Efficiency and Renewable Energy, located at the National Renewable Energy Laboratory.

Figure 1
(Invited) Modeling the Chemically Induced Stress in Lscf Oxygen-Separation Membranes
Authors: Euser Bryan , Zhu Huayang , Berger John , Kee Robert J. 
Published: February 2020

Strontium- and iron-doped lanthanum cobaltite perovskites (La1-xSrxCo1-yFeyO3-δ) are used for a number of electrochemical applications, including solid oxide fuel cells (SOFCs), oxygen separation membranes, chemical sensors, and catalysts. This paper focuses specifically on La0.6 Sr0.4Co0.8Fe0.2O3-δ, LSCF6482. The material is a mixed ionic and electronic conductor (MIEC), with good oxide-ion conduction. The electronic conduction is via small polarons associated with reduced and oxidized states of cobalt. An important aspect of the present study is to understand the coupled effects of defect transport and stress, especially in oxygen-separation membranes. Varying the environmental oxygen pressure on the membrane surfaces induces spatially transient responses of the charge-carrying-defect concentrations, electrostatic potential, and hydrostatic stress. The stress is the result of atomic-scale strain and distortion within the crystal lattice structure. Sufficiently high stress, especially tensile stress, can cause material degradation or failure.
A Nernst–Planck–Poisson (NPP) model is extended to account for the coupled effects of defect transport and chemically induced stress. In addition to the effects of concentration and electrostatic-potential gradients, the Nernst–Planck fluxes include the influence of hydrostatic-stress gradients. The stress model is based on the elastic response of a thin plate, including the effects of oxide-ion vacancy concentrations. The material properties for LSCF6482, including mechanical properties, thermodynamic parameters for the defect chemistry, and charged-defect diffusivities, are obtained by interpreting previously published experimental data. The model is formulated as a system of partial differential equations and solved computationally, predicting transient profiles of defect concentrations, electrostatic potential, and hydrostatic stress.