bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling of a Hollow-in Lithium-Ion Battery for Thermal Design
Authors: Koo Boram , Yi Jaeshin , Shin Chee Burm , Lee Yeongjae , Hong YeongJin 
Published: February 2020

The lithium-ion battery (LIB) is one of the preferred candidates for grid-scale energy storage systems due to its outstanding characteristics such as high energy density, modular scalability, long cycle life, and low self-discharge rate among others.In a batterymodule forgrid-scale energy storage applications, an uneven temperature distribution in thecell can be created depending on theoperating conditions and the types ofthermal management. Uneven temperature distribution in amodule couldcauseanelectricalimbalance and thus lead tothelower performance and shorter life of battery. It is, therefore, important to calculate accurately the uneven temperature distribution in a batterycell in order to achieve the optimum performanceand long lifeof the batterycell.
In this work,amodelingis performed toinvestigate the effects of thermal design on the thermal behavior of ahollow-in lithium-ion battery.The modeling of the potential and current density distributions on the electrodes is validated by the comparison between experimental and modeling discharge curves at various discharge rates from 0.5 C rate to 4 C rate. Then, the thermal modeling of the lithium-ion battery is carried out, which accounts for the ohmic heating and the heat generated due to charge transfer at the electrode/electrolyte interface. The heat generation rate is calculated using the results of the modeling of potential and current density distributions.
Fig.1 shows the schematic diagrams of hollow-in lithium-ion battery. The temperature distribution in hollow-in lithium-ion battery with 4 C rate constant current discharge is shown in Fig. 2.

Figure 1
(Invited) STEM / EELS Characterization of Passive Films Formed on Stainless Steels
Authors: Fujimoto Shinji , Kawano Akihiko , Tsuchiya Hiroaki , Saito Minoru 
Published: February 2020

Passive films formed on stainless steel were characterized using STEM / EELS and XPS. The Fe22Cr alloy was potenitostatically passivated in a pH 8.4 borate buffer solution and 0.5 M sulphuric acid solution. As usually observed Cr enriched passive film was formed in both solutions. The passive film formed in borate buffer solution was slightly ticker, and exhibit lower Cr concentration, compared to that formed in sulphuric acid solution. The EELS with using a position sensitive detector exhibited very detailed chemical sates across the cross section of the passive film. It is revealed that passive film is composed of Cr2O3 and Fe3O4 with small amount of γ-Fe2O3 located at the outer layer. These results did not necessarily coincide with the observation by XPS, that is, inner oxide layer rich in Cr and covering hydroxide of mainly Cr or Fe depending on solution pH are usually obtained by XPS. This inconsistency might be explained by the difficulty to keep top surface non-crystalline hydroxide layer during sample preparation using a FIB (focused ion beam) technique. The observation of passive film formed in ionic liquid using STEM / EELS will be also presented comparing the observation by AES with sputtering.
(Invited) Liquid Phase Ion-Gun Technique for Degradation and Evaluation of Oxide Films
Authors: Fushimi Koji 
Published: February 2020

Halide ions in environments destabilize oxide films on materials and lead to a local corrosion of the material. In order to investigate a quantitative effect of halide ions on oxide degradation, an electrochemical technique with a concentrating method of halide ions on the oxide in an experimental setup is necessary. Liquid phase ion-gun (LPIG), in which silver halide layer on a silver microelectrode is reduced in liquid phase, is one of the beneficial techniques to concentrate halide ions the vicinity of the material surface. Fushimi and Seo developed an LPIG as a chloride ion-generator and successfully applied in boric acid-borate buffers to degrade passive film on pure iron locally and to induce the local corrosion [1, 2]. Degradation reaction of the film was classified into three processes; depassivation induction, film depassivation, and corrosion propagation or repassivation, from electric charges consumed by both LPIG microelectrode and specimen electrode. Since an electric charge consumed on the microelectrode for the generation of chloride ions during the induction process corresponds to the amount of chloride ions needed for the degradation of passive film, the stability of passive films on different crystallographic grains were also evaluated. LPIG was also combined with electrochemical quartz crystal microbalance and used to investigate local corrosion of copper [3]. Lee and Fushimi have developed another type of LPIG, in which silver sulfide layer on the silver microelectrode is reduced to generate sulfur species, and applied to sulfide surface of silver electrode [4] and type 316L [5], 304, 430 and 443 [6] stainless steels.
In this paper, the beneficial features of LPIG technique for investigating the initiation of local corrosion on iron-based materials are reviewed. The quantitative analyses for the halide ions generated from LPIG microelectrode will also be discussed.
References
[1] K. Fushimi, K. Azumi, M. Seo, J. Electrochem. Soc., 147(2), 552-557 (2000).
[2] K. Fushimi, M. Seo, J. Electrochem. Soc., 148(11), B450-B456 (2001).
[3] F. Falkenberg, K. Fushimi, M. Seo, Corros. Sci., 45(11), 2657-2670 (2003).
[4] J.-S. Lee, K. Fushimi, Y. Kitagawa, T. Nakanishi, Y. Hasegawa, J. Electrochem. Soc., 162(4), C115-C120 (2015).
[5] J.-S. Lee, Y. Kitagawa, T. Nakanishi, Y. Hasegawa, K. Fushimi, J. Electrochem. Soc., 162(14), C685-C692 (2015).
[6] J.-S. Lee, Y. Kitagawa, T. Nakanishi, Y. Hasegawa, K. Fushimi, submitted.
Effect of Cr Content on Pit Initiation Behavior at MnS Inclusions in Fe-Cr Steels
Authors: Asano Shinpei , Muto Izumi , Sugawara Yu , Hara Nobuyoshi 
Published: February 2020

It is well known that Cr improves the pitting corrosion resistance of stainless steels. In chloride-containing environments, MnS inclusions act as a preferential site for pit initiation of stainless steels. In this study, a microelectrochemical approach was applied to elucidating the effect of Cr addition on the corrosion resistance of pit initiation at MnS inclusions.
Fe-5Cr, Fe-12Cr, and Fe-18Cr steels, containing 0.027 mass% S, were prepared by vacuum induction melting. Heat treatment was performed at 1123 K for 600 s. After the heat treatment, the steels were water-quenched. Their surfaces were polished down to 1 μm diamond paste. Since the MnS inclusions are darker than the steel matrix, they are clearly visible in the as-polished condition without etching, and it was confirmed that the inclusions consisted of Mn, S, and a small amount of Cr. This type of inclusion was simply referred to as MnS inclusion.
In order to ascertain the dissolution potential of the MnS inclusion, the potentiodynamic polarization curves for the small areas with the inclusion were taken in a naturally aerated 0.1 M Na2SO4 solution at 298 K. As shown in Fig.1a, the increase in current density around 0.05 V was a characteristic common to all the specimens. After the polarization, the inclusions were observed by a field emission scanning electron microscope equipped with an X-ray energy-dispersive spectrometer, and it was concluded that the current increase around 0.05 V was due to the dissolution of the MnS inclusion.
Figure 1b shows the potentiodynamic polarization curves for the small areas with the inclusion in a naturally aerated 0.1 M NaCl solution at 298 K. In the cases of Fe-5Cr and Fe-12Cr, the large current increases were observed around 0.05 V. It was suggested that the MnS dissolution directly brings about the initiation of pit (Fig1c-e). On the other hand, no stable pit was initiated on Fe-18Cr. Moreover, even the initiation potential of meta-stable pit was higher than the inclusion dissolution potential. The addition of Cr in the steels was shown to improve the repassivation ability of the steel matrix.

Figure 1
Modeling the Effect of High-Temperature Alloys on Corrosion inside Molten Salt Systems
Authors: Tavakoli Bahareh Alsadat , Shimpalee Sirivatch , Weidner John W. , Garcia-Diaz Brenda L. , Martinez-Rodriguez Michael J. , Olson Luke Christopher 
Published: February 2020

The corrosion of high-temperature alloys is a major challenge for the development of concentrated solar power (CSP) systems using molten halide salts. High-temperature alloys are usually iron-, cobalt- or nickel-based alloys containing more than 20% chromium (or 30% for cobalt), which is adequate to form a protective passive layer against further oxidation. Unlike the more conventional oxidizing media, most oxide films are chemically unstable and tend to be completely soluble in the corroding molten halide melts. Therefore, passivating oxides are not adequate and corrosion occurs primarily through the oxidation and subsequent dissolution of alloying elements into the melts.
USC-Columbia and SRNL have developed a corrosion model that predicts corrosion rates and mechanisms of high-temperature alloys in contact with molten halide salt under conditions predicted for a prototypical high temperature CSP heat transfer system. The corrosion model is coupled to a computational fluid dynamics (CFD) component that considers temperature and fluid flow effects on the corrosion rates predictions. Several high-temperature alloys such as Incoly 800H, Haynes NS-163 and Haynes 230 are considered. Kinetic and mass transfer parameters for the alloys undergoing corrosion in the model are baselined to experimental corrosion measurements. Baseline corrosion measurements were conducted in static immersion cells at 850°C and in a thermosiphon designed to allow exposure of the coupons to flowing molten salt at a hot zone temperature of ~933°C and a cold zone of ~880°C. The model is also capable of considering the effect of magnesium cathodic protection for these alloys in contact with molten halide salts. The model has been validated against experimental investigations and good agreement has been achieved between model predictions and experimental observations.
Figure 1 shows a comparison of the model prediction and experimental results of corrosion rate, i(A/m2) at 850°C for different alloys in MgCl2-KCl molten salt.

Acknowledgements

The authors gratefully acknowledge the financial support for this work from the DOE EERE SunShot Initiative (DE-AC36-08GO28308) under a subcontract from SRNL to the University of South Carolina. The authors also thank the University of South Carolina Center for Fuel Cells and the CD-adapco group for their support. Figure caption: Comparison of the model prediction and experimental results of corrosion rate, i(A/m2) at 850°C for different alloys in MgCl2-KCl molten salt.

Figure 1
The Effect of Environmental Stress Crazing on the Corrosion Performance of PET Coated Packaging Steel
Authors: Warren David , de Vooys Arnoud C.A. , McMurray Hamilton Neil 
Published: February 2020

The market for polymer laminated packaging steel is currently growing due to the improved barrier performance, reduced processing by the can maker and increasingly as a result of environmental concerns associated with solvents and health concerns with bisphenol A (BPA), a major component in epoxy phenolic lacquers. Despite the benefits of these laminated systems a concern exists around environmental stress cracking/ crazing (ESC) of the polymer, a phenomenon that accounts for 15% of bulk polymer failures [1].
The primary aim of this paper was to examine the effect ESC has on the corrosion performance of Electro Chromium Coated Steel (ECCS) laminated with polyethylene terephthalate (PET). Electrochemical Impedance Spectroscopy (EIS) was used to characterise the ESC/corrosion phenomena. EIS is a recognised system for assessing organic coatings however it gives a global measure of coating performance thus dye penetrant and scanning vibrating electrode technique (SVET) have been used to spatially characterise the EIS signal.
EIS measurements were carried out over a 4 day period in aqueous 5 wt % NaCl to measure the drop in coating impedance as the coating degrades. This was fitted to an equivalent circuit that is correlated back to the coated system. Dye penetrant (figure 1) and SVET (figure 2) were subsequently used to characterise the influence the crazing has on the failure of the coating.
In brief, an argument is presented that two main features exist; initially there is the openness of the crazes at the surface that provide diffusion routes into the surface although a significant time delay occurs due to the complex diffusion routes offered by the crazes. After the time delay the second feature occurs as diffusion increases and then in turn the conductivity of the coating also increases until conditions become sufficient at the metal/polymer interface for the steel to be attacked. Due to the poor protection offered by the nano scale chromium coating corrosion then ensues.
[1] D. C. Wright, Environmental stress cracking of plastics Shrewsbury: Rapra Technology, 1996.

Figure 1
Effects of CNT-Zinc Hybrid Structure on Corrosion, Scratch and Adhesion Strength of Epoxy Composite Coating
Authors: Daneshvar Fatah Farhad , Sue Hung-Jue , Castaneda Homero 
Published: February 2020

Metal-rich organic coatings are one of the most common methodes to hinder the corrosion in metals. These coatingsDue to environmental concerns and technical challenges there is an intrest in decreasing the required amount of these metals within the organic coatings. Conventionally graphite or carbon black is added to provide a conductive network and decrease the amount of metal within the coating. However due to high perculation thresholds for these filers, high amount of them is required which leads to inferior mechanical properties and promotion of galvanic corrosion. On the other hand it has been shown that Carbon nanotubes (CNT) can form a conductive network in very low amounts. Moreover, CNTs can improve the mechanical properties and tribological properties of the coatings. Damages such as scratch can significantly reduces the protective properties of organic coatings. In this work the effect of CNT-Zn addition and the dispersion method on the corrosion resistance and tribological properties of the epoxy-Zn/CNT hybrid coatings are studied.
Performance Improvement of Organic Solar Cells By the Integrated Antireflection System with Moth Eye Surface and High-Refractive-Index Glass
Authors: Kubota Shigeru , Harada Yoshiki , Sudo Takenari , Kanomata Kensaku , Ahmmad Bashir , Mizuno Jun , Hirose Fumihiko 
Published: February 2020

Organic photovoltaics (OPVs) are considered to have a great potential to solve future energy supply scenarios due to their advantages such as low production and material costs. The power conversion efficacy and lifetime of bulk heterojunction OPVs have been significantly increasing in the last decade, although further improvements will be required for the large-scale commercialization. Because the OPV cell includes a stack of several thin layers, a certain percentages of light energy is always lost by the reflection at the interfaces between the different materials and the absorption in the layers different from the photoactive layer. In addition, due to a low carrier mobility of organic semiconductors, the active layer of OPVs should be very thin (around 100 nm), which makes it difficult to fully absorb incident light. To enhance light absorption in the thin active layer, it is important to adequately design antireflection (AR) system that can trap light into OPVs. Recently, many studies on the AR technique have applied the moth eye texture, which is a nanostructure inspired by the corneal surface of moth’s eyes. In the moth eye coating, the device surface is covered with two-dimensional array of cones with a period and height of a few hundred nanometers. Since the effective refractive index (RI) within the moth eye gradually changes in the direction of the cone axis, the level of reflection can be significantly weakened. In cases where the moth eye texturing is applied to OPVs, it is required that the material used in the texture should have compatibility with the advantage of the OPVs, such as low costs. Therefore, in this study, we employ moth eye structure made by organic polymers, since the textured pattern can be fabricated cost-effectively by nanoimprint lithography with polymeric resists. To reduce the effects of optical mismatch between the low-RI organic polymers and high-RI materials in the OPV cell (e.g., indium-doped tin oxide), we propose a new design of AR system. In this system, the hybrid AR structure, which is composed of the moth eye and multilayer interference coatings, is integrated with a high-RI glass substrate. We numerically investigate the optical properties of OPVs and demonstrate that the proposed AR system is quite useful for attaining broadband and omnidirectional antireflection. In addition, we experimentally measure the effect of the integrated AR design on the photocurrent generation of OPVs to verify the simulation results.
Acknowledgement: This study was partially supported by KAKENHI (26390025) from the Japanese government, and by JST, CREST.
Characterization of Cu-Based I-V-VI Thin Films Using Hybrid Inks
Authors: Cho Ara 
Published: February 2020

Cu(In,Ga)Se2 (CIGS) and Cu2ZnSnSe4 (CZTSe) have been studied as the most promising materials in solar cell research and production area. Until now, CIGS solar cell has already reported over 21 % conversion efficiency. Despite the real progress of efficiency, however, CIGS and CZTS absorbers in photovoltaic cells have been challenged by many problems, such as elemental scarcity, toxicity and structural complexity. Especially, complex stoichiometry and high process temperature are important obstacles to overcome because the elemental ratio of absorbers is hard to control and the bottom-cell can be easily degraded for fabricating high efficient tandem solar cell while the top-cell process is carrying on.
Recently, Cu-based I-V-Vl materials, especially Cu-Sb-S phases, have been highlighted because of their characters, such as a band gap and a high optical absorption co-efficient. In the Cu-Sb-S phases, there are four major phases (CuSbS2, Cu3SbS3, Cu3SbS4, Cu12Sb4S13) but most of research have reported only about synthesis and characterization of nanocrystals.
In this study, thin films of Cu-Sb-S phases were formed using non-vacuum process which is cost-effective. To form thin films of Cu-Sb-S using a non-vacuum hybrid ink, Cu and Sb precursors were coated and sulfurized with a rapid thermal annealing (RTA) process. However, each optimum sulfurization condition is needed to obtain single phase thin films of each material. The fabricating thin films were analyzed and confirmed as target phases. The characteristics of each Cu-Sb-S absorber and photovoltaic performances of fabricated cells will be presented.
Nanostructure Provides a Major Breakthrough in Properties of Transparent Polymer, and Solar Cells, Which Are Encapsulated By Nanopolymer
Authors: Shembel Elena M , Redko Vlad I , Klyui Nikolai I , Yashchenko Larisa , Yarova Nataly 
Published: February 2020

Enerize nanostructured transparent polymer for encapsulation the solar cells provides a new achievements, including the increasing the efficiency of the solar cells even under conditions when the illumination falls on the surface of the polymer coating at an angle; transparency 20% even in the wavelength 250 nm. Additional advantages include reduced weight, increased resistance to degradation by UV and high mechanical strength, stability under prolonged exposure to high and low temperatures, thermal-cycling, mechanical impact, and high relative humidity. Enerize nanostructured polymers are promicing for encapsulation other optical devices including organic light-emitting diodes (OLED).
The nanostructure of the proprietary transparent polymer include the nano clusters and micro-domains in the volume of the polymer. This results in micro lenses, which improve the optical properties of transparent polymer, and add the novelty and feature for solar cells and other optical devices. Composition of the initial materials for the polymer synthesis, parameters of the encapsulation, nature of the semiconductor material of the solar cell provide the synergetic effect on the efficiency of the solar cells after encapsulation. Results of the testing of the properties of the nanopolymer film, including light absorption and reflection; and different types of solar cell based on the silicon, thin film flexible non - silicon solar cell will be discussed during presentation
Perpendicular Stt-Mram Scaling Challenges and Potential Solutions
Authors: Zhong Tom , Thomas Luc , Jan Guenole , Zhu Jian , Liu Huanlong , Lee Yuan-jen , Le Son , Tong Yu-Ring , Shen Dongna , He Renren , Haq Jesmin , Teng Jeffrey , Guisan Santiago Serrano , Iwata-Harms Jodi , Patel Sahil , Lam Vinh , Wang Yu-jen , Torng Terry , Wang Pokang 
Published: February 2020

Significant progresses have been made in recent years in perpendicular spin torque transfer magnetic random access memory (pSTT-MRAM) technology development by many companies or organizations. Commercialization of pSTT-MRAM is more real today than ever in the long history of MRAM technology development. We have recently reported fully functional pSTT-MRAM chips and macros with sub-5ns writing speed based on 90nm and 40nm node CMOS technologies [1,2]. These technologies can be potentially used to replace current embedded non-volatile memories such as embedded flash memories or SRAM and be applies to energy efficient applications such as internet of thing (IOT). In this presentation, we will review recent progresses and discuss STT-MRAM scaling challenges for product at 28nm technology node and beyond in terms of integration schemes as well as magnetic and electrical transport properties. We will also discuss the potential solutions that we see for these challenges.
References:
[1] G. Jan, Symp VLSI Tech, 2014. pp 50-51.
[2] Yu Lu et al, IDEM Technical Digest, 2015 (in press)
Charge Trap Memory Based on Few-Layer Black Phosphorus and High-K Materials
Authors: Wang Kaiyou 
Published: February 2020

Due to the unique properties of the two dimensional material, it has great potential for future information technology devices. Based on field-effect transistors with large hysteresis, consisting of a few-layer black phosphorus channel and a three dimensional (3D) Al2O3/HfO2/Al2O3, we successfully made the nonvolatile charge-trap memory devices. Because of the extraordinary trapping ability of the high-k HfO2, an unprecedented memory window exceeding 12 V is obtained. The device shows a high endurance of over 120 cycles and a stable retention of ∼30% charge loss after 10 years, even lower than the reported MoS2 flash memory. The high program/erase current ratio, large memory window, stable retention and high on/off current ratio, provide a promising route towards flexible and transparent memory devices utilizing atomically thin two-dimensional materials. The combination of 2D materials with traditional high-k charge-trap gate stacks opens up an exciting field of nonvolatile memory devices[1].

References

(1) Qi Feng, Faguang Yan, Wengang Luo and Kaiyou Wang, Nanoscale, 8(2016)2686.