bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of pH and Salinity on Polarization Behavior of Cathodically Protected HY80 Steel, Inconel 625 and Nickel-Aluminum Bronze in Mexican Gulf Seawater
Authors: Baturina Olga A , Strom Matthew James , Martin Farrel J 
Published: February 2020

Metal structures submerged in seawater are subject to corrosion. Corrosion protection is usually implemented by applying negative potentials between -0.8 and -1.0 V vs Ag/AgCl reference electrode [1]. At these potentials, anodic metal dissolution is expected to be suppressed, and the typical dominant reactions that govern electron transfer on the protected surface in seawater are oxygen reduction reaction (ORR) and hydrogen evolution from water. The ORR in basic environments (pH~ 8.4) result in the generation of hydroxyl ions, eliciting an increase in the carbonate (CO3
2-) ions from the carbonate buffer system. When concentrations of CO3
2- and OH- near the electrode surface become sufficient to exceed solubility constants of CaCO3 and Mg(OH)2
compounds, they precipitate on the surface, decreasing the electroactive surface area, and making cathodic protection more efficient [2].
Formation of calcareous deposits on metal alloys is affected by applied potential, DO level, salinity, pH and temperature. Although the influence of DO, pH and temperature on the formation of calcareous deposits have been previously reported [3-5], the effect of salinity level has been overlooked. The effect of pH has been explored only minimally for a limited range of pH (usually ~ 7).
Here, we explore polarization behavior of three cathodically protected alloys (Inconel 625, HY 80 Steel, and C-632 Nickel-Aluminum Bronze used in marine environment as a function of seawater salinity and pH.
Electrochemical experiments were conducted in a three-electrode electrochemical cell (BioLogic, Inc). Freshly polished coupons of three different alloys served as working electrodes (WEs), while platinum mesh and Ag/AgCl in 3M NaCl (BioLogic, Inc) were used as a counter and reference electrodes, respectively. WEs held at -1.0 V were immersed into 0.5, 3.5 or 35 ppt seawater for 24 h, and polarization curves were recorded at 0.6 V/h prior and following the potential hold. Acetic acid, MES and MOPS organic buffers (Sigma Andrich) were used for maintaining pH levels of 5, 6, and 7, respectively. Seawater from Mexican Gulf was collected at Key West, FL.
The influence of salinity and pH on polarization behavior of HY 80 steel is shown in Figures 1 and 2, respectively. The presentation will discuss the reasoning behind the changes in HY 80 Steel, Inconel 625 and C-632 Nickel-Aluminum Bronze polarization behavior under different environmental conditions.
References
[1] V. Ashworth, C.J.L. Booker. Cathodic Protection, Theory and Practice; Ellis Horwood: Chichester, UK, 1986
[2] S.L. Wolfson, W.H. Hartt. Corrosion, 37 (1981) 70
[3] J.S. Luo, R.U Lee, T.Y. Chen, W.H. Hartt, S.W. Smith. Corrosion, 47(1991)189
[4] C. Barchiche; C. Deslouis; O. Gol; P. Refait; B. Tribolett. Electrochim. Acta, 49(2004)2833
[5] P. Refait; M. Jeannin; R. Sabot; H. Antony; S. Pineau, Corros. Sci 90(2015)375

Figure 1
Quantitative Examination of Porous Rust on Steel
Authors: Curry Nicholas , Wills Trevor , Gibbon Simon R , Lyon Stuart B 
Published: February 2020

Despite innumerable years of research, very little is known about the physical structure of rusts on steel, which are presumed to possess a complex structure of pores of various shapes and sizes. There have been few detailed investigations into rust pore structure and no studies that focus specifically on understanding the role that rust porosity plays on the adhesion and performance of protective organic coatings. It is commonly believed that paints that are formulated for “compromised” (i.e. rusty and salty) steel penetrate surface and through thickness pores in order to stabilise and bind the rust together. However, no convincing experimental evidence exists for such a mechanism.
Here we develop a detailed, quantitative, understanding of the porous structure of rust and attempt to directly measure its evolution over time. Characterization of porosity in rust layers is non-trivial, as pore sizes span many orders of magnitude and there is no single technique that can measure across the size range. Thus, a range of complementary techniques have been utilised to measure pore sizes: gas (BET) sorption, mercury porosimetry and helium pycnometry, each of which measures different porosity characteristics across different length scales from the “microporous” (i.e. < 2 nm) through the “mesoporous (2 – 50 nm) to “macropores” of size > 50 nm. We find that for rusts developed using cyclic corrosion testing up to 50% of the porous volume exists in the mesoporous and microporous size ranges with surface areas between 20 and 40 m2 g-1 and that there is significant stratification of porosity between "inner" and "outer" rust layers
X-ray computerised tomography (XRCT) has been subsequently used to directly image pores at a voxel size of around 1 micron in order to follow the evolution of the pore structure with time as a function of environmental exposure. The figure shows the experimental protocol whereby projection images of a corroded wire sample are obtained using x-ray absorption contrast and later combined to generate the 3D volume reconstruction.

Figure 1
Fabrication of Metal-Supported Solid Oxide Fuel Cells by Sinter-Joining Method with Silver Bonding Layer
Authors: Lee Sanghun , Jang Young-hoon , Shin Hoyong , Bae Joongmyeon 
Published: February 2020

Solid oxide fuel cell (SOFC) is an energy conversion device which generates electricity from hydrogen. SOFC is attracting attentions because of its high energy conversion efficiency and low material cost. For these reasons, SOFC are widely studied to be applied to various power generation systems such as stationary power plant, residential power system, auxiliary power unit (APU), etc. For APU applications, high mechanical strength is required to endure mechanical vibration and external shock during the driving of vehicles, which makes ceramic-based SOFC unsuitable. To overcome this limitation, metal-supported SOFC has been proposed. Metal-supported SOFCs are composed of metal substrate which supports ceramic layers of anode, electrolyte, and cathode. For more than past ten years, various types of metal-supported SOFC have been developed in many organizations. However, conventional metal-supported SOFCs had limitations of high cost thin film coating process such as sputtering, plasma spray, etc, sintering at reducing atmosphere, and unsintered cathode. In our research group, metal-supported SOFCs fabricated by sinter-joining method were developed. To fabricate metal-supported SOFCs by sinter-joining method, metal substrates were bonded to conventional ceramic cells by bonding paste composed of mixture of stainless steel, nickel oxide, yittria-stabilized zirconia (YSZ). Recently, silver has been proposed as bonding materials. By using silver as bonding materials, bonding of ceramic cell can be performed at temperature lower than 950 °C at air atmosphere, which enables full sintering of cathode. This has been rarely reported because conventional metal-supported SOFCs were fabricated by sintering at reducing atmosphere to prevent oxidation of metal substrate during the sintering. Furthermore, it is believed that electrical conductivity, thermal conductivity are improved, leading to lower ohmic resistance and better temperature distribution of metal-supported cells.
In this work, 5 x 5 cm2 metal-supported SOFCs with silver bonding layer was successfully fabricated. The microstructure of bonding layer was investigated, which showed good adhesion of silver bonding layer. Electrochemical performance and impedance spectra were studied. Power density of 433 mW/cm2, ohmic resistance of 0.52 Ω cm2, polarization resistance of 0.16 Ω cm2 at 800 °C were obtained, and it is believed that high power density was attributed to low polarization resistance by full sintering of cathode. Metal-supported SOFCs fabricated by sinter-joining method showed 10 times higher mechanical strength than conventional ceramic cells.
Suppression of Chromium Poisoning in SOFC Cathode Using Chromium Trapping Materials
Authors: Lee Jong-Ho , Kim Hyojin , Yoon Kyung Joong , Park Mansoo , Kim Hyoungchul , Son Ji-Won , Kim Byung-Kook , Lee Hae-Weon 
Published: February 2020

Solid oxide fuel cells (SOFCs) represent one of the most environmentally friendly and versatile technologies for generation of electrical power and heat from a variety of fuels through electrochemical reactions. Currently, one of the major challenges for commercialization of SOFC technology is the lack of long-term reliability at high temperatures. Especially the high-temperature degradation of SOFC materials with respect to contaminants, structural degradation and material decomposition is known to be the main cause of poor reliability of SOFCs which makes significantly mitigating a broad implementation of SOFCs. Thus, a fundamental understanding of the degradation mechanisms of SOFC materials is needed to find the best degradation mitigation strategies and apply them in order to advance the commercialization of SOFCs.
Among many sources of degradation of solid oxide fuel cells (SOFCs), chromium poisoning of cathode has been one of the major concerns for commercial development and deployment. Chromium evaporates from the metallic components of the stack and system in oxidizing atmosphere, and deposits on the active sites of the cathode, leading to degradation of electrode performance. One of the most general approaches to suppress chromium poisoning is to cover the metallic components with protective coating, and various coating materials and deposition techniques have been proposed. However, it is difficult to form sufficiently dense and stable coating on entire part of the potential chromium source of the system. Therefore, solely relying on protective coating for suppression of chromium poisoning is not considered to be reliable, and it is desirable to have additional means to further block chromium vapor from reaching cathode.
In this presentation, effect of chromium poisoning on cathode reaction was studied using impedance spectroscopy to illuminate the degradation process in SOFC cathode. From this investigation, especially focused on the air side of SOFCs which occupies the largest portion of SOFC deterioration, we want to identify the underlying degradation mechanisms and propose possible mitigation strategies based on our experimental results.
Development of Ceramic Materials and Application of Novel Physical Analysis Methods to Enhance Solid Oxide Fuel Cells and Solid Oxide Electrolysis Cells
Authors: Lust Enn , Lillmaa Kadi , Nurk Gunnar , Kanarbik Rait , Möller Priit , Kivi Indrek , Vestli Mihkel , Maide Martin , Korjus Ove , Salvan Laur Kristjan , Kukk Freddy 
Published: February 2020

Various physical methods (SEM-EDX, TEM, EXAFS, FIB-TOF-SIMS, high temperature X-ray diffraction, gas adsorption, etc.) and electrochemical methods have been used complexly for detailed analysis of ceramic materials with the perovskite structure, considered as promising alternatives to Ni-based solid oxide fuel cell (SOFC) anodes as well as solid oxide electrolysis cell (SOEC) cathodes. Comparative analysis of the data obtained by novel in situ/in operando and electrochemical methods used for characterizing the electrode materials and processes gives deeper insight into the background of various processes taking place in the materials and enables to develop new materials for various purposes. Some examples including in operando high-temperature X-ray diffraction, in operando X-ray absorption and FIB-TOF-SIMS studies will be discussed. Unit cells relaxation and interdiffusion in solid oxide fuel cells and carbon dioxide and water co-electrolysis cells will be discussed. Influence of chemical composition and preparation methods of the materials for electrolytes, electrodes and chemical barrier layers on the SOFC and SOEC characteristics will be analyzed.
Quality Assurance of Solid Oxide Fuel Cell (SOFC) and Electrolyser (SOEC) Stacks
Authors: Lang Michael , Auer Corinna , Couturier Karine , Sun Xiufu , McPhail Stephen J. , Malkow Thomas , Fu Qingxi , Liu Qinglin 
Published: February 2020

Many research facilities and industrial companies worldwide are engaged in the development and the improvement of solid oxide fuel cells/stacks (SOFC) and also of solid oxide electrolysis cells/stacks (SOEC). However, the different stacks cannot be easily compared due to non-standardized test programs. Therefore the EU-funded project “SOCTESQA” which started in May 2014 has the aim to develop uniform and industry wide test modules and programs for SOC cells/stacks. New application fields which are based on the operation of the SOC cell/stack assembly in the fuel cell (SOFC), in the electrolysis (SOEC) and in the combined SOFC/SOEC mode are addressed. This covers the wide range of power generation systems, e.g. stationary SOFC µ-CHP, mobile SOFC auxiliary power unit (APU) and SOFC/SOEC power-to-gas systems.
In order to optimize the test programs, which consist of different test modules, several testing campaigns have been performed. The project partners apply the developed test procedures on identical SOC stacks. In this project 5-cell short-stacks with anode supported cells (ASC) were used, which were provided by an established stack supplier. Altogether 10 pre-normative test modules were developed: Start-up, current-voltage curve, electrochemical impedance spectroscopy, reactant utilization, reactant gas composition, temperature sensitivity, operation at constant current, operation at varying current, thermal cycling and shut-down.
The presentation compares the results of the test modules of the different project partners. Important aspects are the evaluation of the results in terms of repeatability of the different testing campaigns and the reproducibility of the results among the partners. Electrochemical properties, e.g. open circuit voltage (OCV), area specific resistance (ASR), power density, fuel utilization (FU) and impedance values of both stack and repeat units (RU) are presented. Moreover, the results are discussed in context to the test input parameters. Another important issue is the reproducibility of the different test methods, e.g. jV-characteristics and EIS-spectra. Finally, important aspects for the determination of reproducible degradation rates of SOC stacks will be presented and discussed.
In-Situ Formation of Nano-Structured Cathode on Metal Supported SOFC
Authors: Zhu Tenglong , Zhong Qin , Han Minfang 
Published: February 2020

Metal supported solid oxide fuel cells (MS-SOFC) possess several advantages like good mechanical property, easy assembling, fast start-up and capability to maintain redox stable due to fuel leakage. However, it has been a critical challenge to deposit cathode on the metal supported cell in the oxidizing atmosphere, which is mainly limited by the low calcination temperature yielding vulnerable electrolyte-electrode interface. The cathodes prepared in the protecting atmosphere are also not satisfied, instead it will increase the complexity of the cell fabrication process.
Lower down the cathode deposition temperature using aqueous infiltration has become one of the optimized methods for MS-SOFC. Also, we have proposed an alternative way for the fabrication of metal supported single cell with robust cathode through whole cell reduction. Here, we present results of both above two approaches for the fabrication of nano-structured cathodes in MS-SOFC. The cells in this study are based on Fe-Ni (1:1 in mol ratio) support, Fe-Ni/YSZ anode and YSZ electrolyte prepared through tape-casting, thermal isostatic pressing and co-firing.
As illustrated in the following schematic configuration, La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) cathodes were deposited in the porous YSZ layer of the pre-reduced Ni-Fe|Ni-Fe-YSZ||YSZ||P-YSZ substrate by infiltration and fired at the cell operation temperature around 700 oC. A-site deficiency of ~4-8% was introduced into LSCF cathode and was expected to enhance the sintering activity of LSCF nano particles at low calcination temperature and to enhance the cathode performance by the excess cobalt and iron oxide at LSCF surface. As in the second approach, Sr0.95Ti0.3Fe0.63Ni0.07O3-δ – Gd0.1Ce0.9O1.95 (STFNi-GDC) graded cathode will be screen printed on the NiO-Fe2O3|NiO-Fe2O3-YSZ||YSZ|GDC substrate and fired at high temperature in air as normal cathode preparation procedure. Then the whole cell will be reduced in H2-Ar to obtain Fe-Ni alloy support and reduced STFNi cathode with in-situ exsolved (Fe,Ni) alloy nano particles anchored in the oxide surface. During the cell test, the reduced STFNi-(Fe,Ni) will be re-oxidized in air, forming the surface decorated iron and cobalt oxide particles, which were presumably to be expected to increase the cathode performance through improvement of oxygen surface exchange coefficient.

Figure 1
All-Solid-State “Lithim-Free” Microbatteries Characterization By Electrochemical Impedance Spectroscopy Coupled Wih X-Ray Photoelectron Spectrometry
Authors: Ferreira Gomes Franck Ferreira , Franger Sylvain , Guy-Bouyssou Delphine 
Published: February 2020

For several decades, the miniaturization of nomadic electric systems has made the world of energy storage evolve. Indeed, these devices are getting progressively smaller and smaller, and more powerful. This makes more difficult the integration of conventional batteries into these modern devices including; incompatibilities due to their sizing, life-time and limited cyclability, risks of inflammation, risk of liquid electrolyte leakage. In response to these difficulties, the "lithium-free" all-solid-state thin film microbatteries provide answers to the manufacturers. They can reach a potential of 0V [1], far below the capability of lithium and lithium-ion batteries. Furthermore, these micro batteries are thinner, more flexible, safer due to the absence of liquid electrolyte. These micro-devices can be integrated into diverse applications as connected watches, SmartCards, RFID Tags, or even be integrated into contact lenses to power the autofocus system.
Li-Free microbatteries are composed of a platinum current collector, LiCoO2 as positive electrode, LiPON glass as solid electrolyte and a current collector of copper. The lithium initially contained in the cathodic insertion material is electroplated on the copper current collector during the initial charge, to create a metallic lithium anode and make the battery operational. However, this technology, offering a lot of advantages, still remains not fully understood and consequently difficult to control.
The thin-film design makes individual characterization difficult after cycling. Analysis of the surface with X-ray Photoelectron Spectrometry (XPS) and Auger Electron Spectroscopy (AES) enable determining the chemical composition of the Li-Free microbatteries after cycling. The use of Electrochemical Impedance Spectroscopy (EIS), can also provide information about the operating behaviour and ageing of these technologies and finally help in better manufacturing. This study is focused on the non-destructive characterization of lithium-free microbatteries by means of the Electrochemical Impedance Spectroscopy coupled with X-ray Photoelectron Spectrometry and Auger Electron Spectroscopy, and shows necessary mechanisms during the first charges and discharges of the battery for ulterior good performances upon cycling. With this adapted protocol [2], the battery can now exhibit a lifetime and cyclability similar to conventional lithium metallic and lithium-ion microbatteries.
References :
[1] Neudecker and al., J. Electrochem. Soc., 147 (2) 517-523 (2000)
[2] Larfaillou and Guy-Bouyssou. U.S. Patent 2015325878 (2015)
Thick Binder-Free Electrodes for Li-Ion Battery Fabricated Using Templating Approach and Spark Plasma Sintering Reveals High Areal Capacity
Authors: Elango Rakesh , Demortiere Arnaud , De Andrade Vincent , Morcrette Mathieu , Seznec Vincent 
Published: February 2020

The templating approach is a powerful method for preparing porous electrodes with interconnected well-controlled pore sizes and morphologies. The optimization of the pore architecture design facilitates electrolyte penetration and provides a rapid diffusion path for lithium ion, which becomes even more crucial for thick porous electrodes. In the present work, we used NaCl micro-size particles as templating agent for the fabrication of 1 mm-thick porous LiFePO4 (LFP) and Li4Ti5O12 (LTO) composite electrodes using Spark Plasma Sintering (SPS) technique. These sintered binder-free electrodes are self-supported and present a large porosity (40%) with relatively uniform pores. The electrochemical performances of half and full batteries reveals a remarkable specific areal capacity (20 mAh/cm2), which is four times higher than those of 100 µm thick electrodes present in conventional tape-casted Li-ion batteries
(5 mAh/cm2). 3D morphological study of both electrode types was carried out using µCT full field TXM technique to obtain tortuosity values and pore size distributions leading to a strong correlation with their electrochemical properties. These results also demonstrate that the coupling between salt templating method and SPS technique turn out to be a promising way to reach the ultimate goal in the fabrication of thick electrodes with high energy density.
(Invited) Exploring Exciton Physics in Liquid-Exfoliated 2D Materials
Authors: Rashvand Farnia , Synnatschke Kevin , Chernikov Alexey , Coleman Jonathan N , Backes Claudia 
Published: February 2020

Transition metal dichalcogenides (TMDSs) are a diverse source of semiconducting 2D materials interesting for a number of application areas. Group VI-TMDs are direct bandgap semiconductors in the monolayer form making them attractive in optoelectronics due the possibility of efficient light emission. Their optical properties are dominated by tightly bound excitons with typical binding energies of 100s of meV – significantly larger than in bulk materials or traditional inorganic semiconductors. The physics of these excitons is of both fundamental interest and importance for exploiting these properties in applications and has been explored by linear and nonlinear optical techniques typically on micromechanically cleaved nanosheets.
In this talk I will review our progress on investigating the exciton physics of layered materials exfoliated in the liquid phase. Liquid phase exfoliation has become a popular technique to obtain nanosheets in the form of colloidally stable dispersions suitable for solution processing. It’s an extremely versatile technique that can be applied to a whole host of layered crystals. While dispersions of nanosheets are usually polydisperse containing broad distributions of lateral sizes and thicknesses, they can nonetheless be used to study fundamental physical properties once the distributions are quantified by statistical microscopy. The advantage of the technique is the broad applicability and characterisation of an ensemble eliminating potential variations across different nanosheets. In addition, environmental effects can be conveniently studied by exchanging the liquid environment.