bluuebunny/crossref_metadata_2025_split huggingface dataset:
State of Health Battery Estimator Enabling Degradation Diagnosis
Authors: Dubarry Matthieu , Berecibar Maitane , Baure George , Omar Noshin , Villarreal Igor 
Published: February 2020

The state-of-health (SOH) estimation is of extreme importance for the reliability and safety of battery operation in large scale energy storage systems. How to estimate SOH for an assembly of cells in a battery pack remains a subject of great interest.
In this work, a new approach for state of health (SOH) estimation via an automated diagnosis method that could be implemented directly into a battery management system (BMS) is introduced. The approach proposed in this work is a multi-step method that improves the accuracy of the estimation and only requires a multidimensional look-up table to be embedded into the BMS. The embedded look-up table enables a robust diagnosis of the battery degradation with a low computing cost.
The first step of the methodology is the emulation [1] of a cell from its half-cell data. The second step is the selection of features of interest (FOI) [2] from its voltage response. Next, the variations of these FOIs due to different degradation paths are compiled into a multidimensional look-up table. Lastly, SOH diagnosis is performed by comparing the experimental FOI values to the look-up table. The novelty of this approach resides in the consideration of the variations of all FOIs concurrently by using detection in an n-D space for n FOIs. This simultaneous analysis of multiple parameters provides accurate predictions even when each FOI taken separately cannot provide a conclusive diagnosis.
Our study presents a method which was very light on calculation at the BMS level and was accurate for 90% of all the possible degradation paths for commercial GIC//LFP and LTO//NMC cells. Moreover, the area where the method was not accurate can be identified and correlated with the data resolution and thus reduced the probability of an erroneous diagnosis in the field. This poster will present the methodology and its limitations.
Figure 1: Diagnosis error as a function of the LLI/LAMPE/LAMNE split at 10% capacity loss for the GIC//LFP cell (top) and the LTO//NMC cell (bottom). Diagnosis error on LLI, LAMPE and LAMNEestimations are respectively in the left, middle and right columns.
References
[1] M. Dubarry, C. Truchot, B.Y. Liaw, J. Power Sources, 219(2012) 204-216.
[2] M. Berecibar, F. Devriendt, M. Dubarry, I. Villarreal, N. Omar, W. Verbeke, J. Van Mierlo, J. Power Sources, 320(2016) 239-250.

Figure 1
Effect of Cathodic Kinetics on Intergranular Corrosion of AA5083 Under Atmospheric Conditions
Authors: Khullar Piyush , Kelly Robert G. 
Published: February 2020

Al-Mg 5XXX series alloys are widely used for marine applications due to their corrosion resistance. However, alloys containing more than 3 wt% Mg, when exposed to standard service temperatures for extended periods of time are known to become sensitized and susceptible to localized corrosion; particularly intergranular corrosion (IGC). Many studies have investigated this IGC phenomenon in AA5XXX and attribute it to precipitation of a more anodic β-phase (Al3Mg2) along grain boundaries after exposure to environments during service in which the surface temperatures can exceed 60 C repeatedly. The majority of the electrochemical studies to understand IGC for AA5083 have been conducted in full immersion under potentiostatic or galvanostatic conditions, but much of the marine infrastructure is exposed to atmospheric conditions/thin films.
This study aims to develop a quantitative understanding of the effect of cathodic kinetics on IGC propagation at open circuit conditions. A new experimental setup using a sintered Ag/AgCl electrode as a combined reference and counter electrode was used to measure cathodic kinetics in thin films. This setup avoided the counter electrode products usually associated with a platinum electrode (H+ or OH-) and maintained uniform current density by placing the electrode right above and parallel to the sample.
Preliminary results indicate that under open circuit conditions (as experienced during service), the cathodic kinetics govern the IGC behavior under droplets/thin films. Different oxidizers like ozone (introduced in the gas phase) and potassium persulfate (introduced in solution) were used to increase cathodic kinetics. AA5083 samples were also coupled to carbon steel, which acted effectively as a galvanostat by suppling the cathodic current required to sustain the anodic activity on AA5083.
Initial thin film electrochemical results agree well with the existing corrosion framework for IGC in full immersion. An understanding of IGC in thin films/atmospheric exposures will provide a basis for developing a framework for IGC in service conditions.
Superhydrophilic and Superhydrophobic Aluminum Alloys Fabricated By Pyrophosphoric Acid Anodizing
Authors: Kikuchi Tatsuya , Kondo Ryunosuke , Nakajima Daiki , Natsui Shungo , Suzuki Ryosuke O. 
Published: February 2020

Introduction

Recently, we demonstrated the fabrication of anodic alumina nanofibers via anodizing in a new electrolyte, pyrophosphoric acid (H4P2O7). Interestingly, the aluminum surface covered by the anodic alumina nanofibers exhibited a superhydrophilic behavior with a contact angle measuring less than 10°. In the present investigation, we described the fabrication of superhydrophilic and superhydrophobic aluminum alloys via pyrophosphoric acid anodizing and subsequent SAM modification.

Experimental

Two kinds of aluminum specimens (5N aluminum and 3004/1N30/8021 aluminum alloys) were ultrasonically degreased and chemically polished. The specimens were anodized in a concentrated pyrophosphoric acid solution at a constant cell voltage of 25-75 V for 60 min. The anodized specimens were immersed in a 0.5 mM fluorinated phosphoric acid SAM (3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctylphosphonic acid: FOPA)/ethanol solution at 293-323 K for 48 h. anodized specimens were examined by field emission scanning electron microscopy (FE-SEM). The water contact angles were measured by an optical contact angle meter (2 µL in water volume for hydrophilic measurements and 4 µL for hydrophobic measurements).

Results

Anodizing of aluminum and its alloys in a pyrophosphoric acid solution caused the formation of numerous anodic alumina nanofibers on the aluminum surface. During anodizing of aluminum alloys, many intermetallic compounds were exposed to the surface with anodizing time increase, and the nanofiber-tangled intermetallic particles were formed on the surface. The contact angle decreased with the anodizing time, and the nanofiber-covered aluminum alloys exhibited a superhydrophilic behavior measuring less than 3° in the contact angle (Figure 1, anodizing voltage: Ua = 75 V). As the surface of the nanofiber-covered aluminum alloys was modified with fluorinated phosphoric acid SAMs (solution temperature: Tim = 293-313 K), the contact angle drastically increased with the immersion time and temperature. These aluminum alloys exhibited a superhydrophobic behavior measuring more than 150° (Figure 2).

Figure 1. Changes in the water contact angle, θ, with the anodizing time, ta, on the 5N aluminum and 3004 aluminum alloy surfaces after anodizing in a pyrophosphoric acid solution (293 K) at 75 V.

Figure 2. Changes in the water contact angle, θ, with the immersion time, tim, on the nanofiber-covered aluminum alloys (3004). The specimens were anodized at 75 V for 10 min, and then were immersed in a 0.5 mM FOPA-SAM/ethanol solution.

Figure 1
Influence of Major Alloying Elements on the Corrosion Resistance of Trivalent Chromium Conversion Layer Coated AA 2024
Authors: Saillard Romain , Viguier Bernard , Odemer Gregory , Zanna Sandrine , Seyeux Antoine , Marcus Philippe , Fori Benoît , Blanc Christine 
Published: February 2020

This work was performed in the framework of the NEPAL FUI project. CIRIMAT was financially supported by the French Ministry of Economy and industry (BPI-France), the Région Occitanie/Pyrénées-Méditerranée and the European Union (FEDER/ERDF).

This work is a part of the NEPAL project (NEw Protections for ALuminum) that aims to replace hexavalent chromium treatments largely used in aeronautic industry by new trivalent chromium conversion layer. We studied here the influence of major alloying elements of the alloy on the growth on the conversion layer and therefore its corrosion properties.
The study was carried out on an AA 2024 cold rolled 3 mm thin sheet. Three microstructures were studied: i) a T3 metallurgical state ii) a T3 state followed by a tempering at 190°C for 12 h to induce Cu precipitation (aged sample) and iii) a T3 state followed by a prolonged solution heat treatment at 494°C for 40 minutes to induce the formation of a Mg-depleted zone on the near surface of the alloy (solution heat treated sample). The microstructures were characterized by transmission electron microscopy (TEM).
The corrosion behavior of both uncoated and coated samples was evaluated by corrosion potential (Ecorr) measurements, plotting of polarization curves and electrochemical impedance spectroscopy (EIS) measurements performed at Ecorr for various immersion times. For a better understanding of the conversion layer coated alloy corrosion properties, surface analyses of the AA 2024 samples at each step of the conversion layer process were performed by combining X-ray photoelectron spectroscopy (XPS), Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and cyclic voltammetry measurements.
Results showed the growth of a thick Mg-rich naturally formed oxide for the solution heat treated sample leading to a widening of the passivity plateau observed on the polarization curve for the uncoated sample compared to T3 uncoated sample. This was associated with the formation of a Mg-depleted zone on the near surface of the alloy; however, preferential dissolution of Mg occurred during the pre-treatment (degreasing and deoxidation) for both the T3 and solution heat treated samples so that the kinetics and mechanisms of the conversion layer growth and its corrosion properties were similar for both samples. For the aged alloy, TEM observations showed a dense precipitation of intergranular and intragranular Al2CuMg. These precipitates were assumed to contribute significantly to the Cu enrichment observed on the sample surface after degreasing and deoxidation leading to a Cu-rich conversion layer with a lower corrosion resistance compared to that formed on the T3 sample.
Depth Profiling of TiO2 Nanotubes in Morphology, Composition and Structure
Authors: Schmuki Patrik 
Published: February 2020

Depth profiling of TiO2 nanotubes in morphology, composition and structure

Shiva Mohajernia, Anca Mazare, Patrik Schmuki

Department of Materials Science WW-4, LKO, University of Erlangen-Nuremberg, Martensstrasse 7, 91058 Erlangen, Germany

In the past decade, anodically formed self-organized TiO2 nanotube layers attracted considerable scientific interest (see e.g. reviews [1,2]). This is mainly due to the fact that these layers combine the defined nanotubular geometry with a broad range of functional features inherent to TiO2. Particularly in photoelectrochemical and photocatalytic applications nanotubular layers have shown remarkable results.
In this work, we compare composition, structure and morphology of the tube layers using depth profiling techniques (GDOES, TOF-SIMS), sectioning techniques (ion milling), TEM, and integral methods (thermal desorption), to achieve an understanding of how key functional features are and can be embedded in TiO2nanotube arrays.
REFERENCES

P. Roy, S. Berger, P. Schmuki, Angew. Chem. Int. Ed. (2011), 2904

K. Lee, A. Mazare, P. Schmuki, CHEMICAL REVIEWS, 114 (2014) 9385
(Invited) Charge Traps, Temperature- and Bias-Stress Stability of Alumina Dielectric / Indium Gallium Arsenide Gate Stacks
Authors: McIntyre Paul C. 
Published: February 2020

Both interface defects and border traps - charge traps in the gate oxide - influence the behavior of InGaAs metal-oxide-semiconductor (MOS) devices. This presentation will summarize the different effects of interface and border traps on the temperature- and bias-stress behavior of aluminum oxide/InGaAs MOS gate stacks, with particular emphasis on threshold voltage stability. The influence of local interface chemistry and the complex role of hydrogen as a defect passivant are highlighted.
In one set of experiments, a temperature dependent border trap response for Al2O3 gate dielectrics is investigated. This behavior is unexpected for defects that have typically been reported to charge and discharge through direct tunneling of electrons from the n-type substrate. Temperature dependent border trap frequency dispersion of the accumulation capacitance and conductance is found to be correlated with the presence of a defective interfacial layer, which can be intentionally produced either by excessive exposure to hydrating or oxidizing species during atomic layer deposition of Al2O3 or by use of a previously-reported aqueous HCl wet clean of the InGaAs surface prior to ALD. These results point out the sensitivity of the temperature dependence of the border trap response in metal oxide/III-V MOS gate stacks to the presence of processing-induced interface oxide layers, which alter the dynamics of carrier trapping at defects that are not located at the semiconductor interface.
We also report on the effects of pre- and post-atomic layer deposition (ALD) defect passivation with hydrogen on the trap density and reliability of Al2O3/InGaAs gate stacks. Reliability is characterized by capacitance-voltage hysteresis measurements on samples prepared using different fabrication procedures and having different initial trap densities. Despite its beneficial ability to passivate both interface and border traps, a final forming gas (H2/N2) anneal (FGA) step is found to induce a significant hysteresis. This is caused by hydrogen depassivation of defects in the gate stack under bias stress, supported by the observed bias stress-induced increase of interface trap density, and strong hydrogen isotope effects on the measured hysteresis. Additional strategies, beyond hydrogen annealing, for more stable interface defect passivation on InGaAs will be discussed briefly.
Development of Environmentally Conscious Electrodeposition Process "Solid Electrodeposition (SED)"
Authors: Yanagimoto Hiroshi , Hiraoka Motoki , Sato Yuki , Iisaka Hirohumi , Murai Jyunya , Itagaki Masayuki , Akamatsu Kensuke 
Published: February 2020

Conventional electrodeposition process is widely used for various kinds of functional parts such as electronics, anti-corrosion, decoration and so on. However, this process has serious problem due to a large quantity of waste fluid including toxic substance. Recently, environmental regulation has been strengthened, so that the production line may be needed to be closed system for recycling the waste fluids. Moreover, the additionl processes such as masking and etching is indispensable in producing the patterned circuit board, leading to high cost for final products. We have developed the novel electrodeposition process to solve the environmental and cost problems of a conventional electrodeposition. As shown in Fig. 1, the novel deposition system is simply composed of electrodes, metal solution and polyelectrolyte. By applying potential between two electrodes, metal films are deposited at solid-solid interface, i.e., cathode electrode and polyelectrolyte; electrolyte solution is separated from cathode electrode by polyelectrolyte in which metallic ions can be diffused through ion-exchange reaction. Therefore, when this system is accumulated into small probe system, this process enables electrodeposition of metals only by attaching polyelectrolyte surface into cathode surface in a serial patterning manner, whereas conventional electrodeposition process is based on immersing the substrate of interest into electrolyte solution. We call this novel system, “solid electrodeposition (SED)”. The characteristics of the process are as follows.
1) The system needs only small amount of electrolyte solution, and washing of the cathode substrate after metal deposition is not necessary because of growth of the films at solid-solid interface, leading to much small amount of waste solution.
2) Site-selective deposition can be achieved only by controlling the contact area of the polyelectrolyte used for deposition (Fig. 2a).
3) Since the deposition can proceed through diffusion of metal ions through fine, large amount of ion channels in polyelectrolytes, metal films constructing of tiny crystallites are deposited (Fig. 2b).
Electrical resistivity of the copper films deposited by SED process is comparable with that of bulk copper, indicating high purity, well-defined copper films are deposited on the substrates. From these results, this process offers an effective, environmentally friendly methodology for fabricating metal films in atmospheric conditions and can be, therefore, applied for various microelectronic applications.

Figure 1
Discovery to Product – an Engineer's Perspective
Authors: Mah Dennie T 
Published: February 2020

Electrochemical science and technology has been both a rewarding and intriguing challenge for engineers from all disciplines. Conventional chemistry and chemical engineering curricula do not fully prepare future practitioners to take advantage of the potential money making opportunities lying in this area, After 40 years of working in the chemical industry, many involving electrochemical technology, I have encountered and accumulated some practical tips, traps and heuristics that are not guaranteed to be optimal or perfect, but sufficient for the immediate goals of meeting business objectives. Discussion will include a global outlook of the necessary steps to accomplish a viable commercial scale electrochemical application starting from laboratory bench scale studies, through intermediate pilot plant scale demonstration and finally operation of a industrial facility. Whether the business objective is the production of chemicals trough the use of electrochemistry or the production and storage of energy, many basic principles apply. Commercialization requires a multidisciplinary approach and the earlier a comprehensive engineering work plan is formulate the smoother will be the transition from laboratory to plant. Hopefully, the insights presented will enable current and future practitioners of electrochemical technology to achieve their business goals and expand the utility of this area of science and technology.
Effect of MPL Properties on Temperature and Liquid Water Distribution in a GDL
Authors: Hashimura Sota , Minami Ryotaro , Tamada Yusuke , Hasegawa Noriyoshi , Araki Takuto 
Published: February 2020

Proton exchange membrane fuel cell (PEMFC) is expected to be used as a power source of next-generation automobiles and household cogeneration systems, because of its high power density, fast startability, high efficiency and clean power source. There are many problems for the practical use of the PEMFC. One of the important problems is difficulty to optimization of water and heat management within PEMFC. Proper water management of the PEMFC is important to achieve high power density and durability of components. At the high current density operation, gas transport is blocked by liquid water remaining in a GDL and a gas channel, causing a performance decline with increasing concentration overpotential. Water condition is influenced by temperature in the cell. In particular, at the high current density, temperature gradient strongly affects the water transport. Therefore, it is important to grasp the mechanism of water and heat transport inside the PEMFC. In this study, we investigated the effect of a MPL properties on temperature and liquid water distribution.
In order to visualize the liquid water in the PEMFC, an X-ray CT apparatus was used. The resin impregnated graphite was used as the material of a separator, because its X-ray permeability is close to liquid water. The separetor temperature was controlled by a thermocouple and a cartridge heater inserted in the separator. For the temperature measurement at the CL / GDL interface, an Au - Ni thin film thermocouple with a thickness of about 9 μm was fabricated using MEMS technology.
Differences between with and without MPL in liquid water distribution was observed. The presence of a MPL reduce the amount of liquid water near the CL.
Investigation of Microstructure and Pt Distribution in Catalyst Layer after Accelerated Degradation Test in PEMFC
Authors: Zeng Rong , Zhang Hongyu , Jiang Lijun , Liu Xiaopeng 
Published: February 2020

The membrane electrode assembly (MEA) is the key part of the Proton Exchange Membrane Fuel Cell (PEMFC). Except applying the high efficiency catalyst, to improve the Pt efficiency for oxygen reduction reaction (ORR) by optimizing the microstructure of MEA is also a key point to achieve the high performance and longevity of the low Pt loading MEA. However, it is still difficult to correlate the microstructure of the MEA, especially the microstructure of the catalyst layer (CL) and the performance of the MEA due to the complex physical and chemical processes in the catalyst layer.
In this study, we reported our work on the low Pt loading MEA and the preliminary results of the accelerated degradation test (ADT) of the MEA. The ADT test was conducted under the DOE’s ADT protocol. SEM, associated with back scattered electron imaging (BSE), EDX mapping, EDX linear scan technique, was applied. The spatial distribution of aggregated Pt particles at cathode of our self-made MEAs (Pt loading at anode is kept at 0.05mg/cm2, the Pt loading at cathode is 0.05, 0.15, 0.55mg/cm2 respectively.) was revealed. It suggested three different region of Pt accumulation – the interface between the membrane and the catalyst layer, the main part of the catalyst layer, and the interface between the catalyst layer and the micro porous carbon layer. The significant Pt aggregation happened at the two interface area of the catalyst layer. This implies the different spatial utilization of the Pt catalyst in the catalyst layer. For clarity, Fig 1 shows the BSE images of MEA cathode with Pt loading of 0.1mg/cm2 and the voltage degradation of the MEA during the ADT test. The detailed discussion of the spatial distribution of aggregated Pt particles will be presented at the symposium.

Figure 1
Membrane/Electrode Assembly Water Content Measured with 2 µm Spatial Resolution Neutron Imaging
Authors: Hussey Daniel S , LaManna Jacob M , Baltic Elias , Jacobson David L , Stariha Sarah , Spernjak Dusan , Mukundan Rangachary , Borup Rod L. 
Published: February 2020

Neutron imaging is a completely non-destructive probe of the water content in operating fuel cells. However, the spatial and temporal resolution of the method limits the application range. We report on our continued imaging detector resolution improvements, where we have achieved a spatial resolution of 2 µm. We applied this new detector capability to measure the water content of two different membrane/electrode assemblies where the ionomer to carbon mass ratio (I/C) was the only variable. A 1 cm2active area test section with parallel flow channels was operated as a differential cell at 80 °C at constant voltage. Shown in the figure are the imaged water content at 0.4 V, 100% inlet relative humidity for the I/C = 0.9 and I/C = 1.1.
Figure Caption: Neutron images of the water content of an operating fuel cell at 0.4 V; a) I/C of 1.1, b) 2I/C of 0.9. In both cases, the cathode is toward the top of the image and the anode toward the bottom.
The authors from LANL are supported by DOE Fuel Cell Technologies Office, through the Fuel Cell Performance and Durability (FC-PAD) Consortium; Fuel Cells program manager: Dimitrios Papageorgopoulos. The authors from NIST are supported by the U.S. Department of Commerce, the NIST Radiation and Physics Division, the Director's office of NIST, the NIST Center for Neutron Research, and the Department of Energy interagency agreement No. DE_AI01-01EE50660, program manager: Nancy Garland.

Figure 1