bluuebunny/crossref_metadata_2025_split huggingface dataset:
Model-Based Investigation of Dual Energy Storage Selection for Advanced Start-Stop Vehicles
Authors: Zhang Zhenli , Jin Zhihong , Sisk Brian C 
Published: February 2020

Dual energy storage solutions have seen significant interest as a means to combine high energy content and high power capability in a single energy storage architecture. Such architectures, which can consist of batteries, capacitors, fuel cells, and other devices, have been used automotive and other applications, allowing the requirements of long-term energy support, high charging power, and high discharge power to be supplied by different devices. Examples include 12V li-ion/lead-acid architectures for advanced start-stop, fuel-cell/li-ion high-voltage hybrids, Li-ion/capacitor combinations, and others.
A challenge in combining multiple energy storage devices is ensuring that they are matched in terms of operating characteristics, such as voltage, resistance, and other characteristics. While power electronics (such as DC/DC convertors) are often used, another approach is to simply passively couple the devices. Doing so requires that the energy and power of the devices should be compatible in terms of capacity, voltage and resistance to achieve the optimal system performance. Typically, that means ensuring a high degree of voltage overlap between the two devices over their operational ranges, usually with a focus on open-circuit voltage.
In this work, we consider an alternate approach for highly-dynamic power profiles, such as those found in automotive hybrid or grid-based power regulation. Here, we utilize mismatch between both the open-circuit voltages and resistances of the two devices to steer current into a higher-voltage, lower-resistance device during a high-current pulse, and then toward a low-voltage, high-energy device during periods of low current. We use electrochemical and equivalent-circuit models to study the current split, voltage, and SOC response during a variety of charge and discharge pulses and some designed driving profiles in order to understand the trade-offs between these different selections.
High-Performance Aqueous Redox Flow Battery Using Non-Toxic Organic-Inorganic Electrolyte
Authors: Lin Kaixiang , Chen Qing , Marshak Michael P. , Gerhardt Michael R. , Eisenach Louise , Gordon Roy G. , Aziz Michael J. 
Published: February 2020

The use of quinone/hydroquinone couples in aqueous redox flow batteries is a promising pathway toward cost-effective stationary electrical energy storage.[1]-[3] Remaining challenges, such as membrane crossover of undesired species, molecule stability, and cost of containment for toxic and corrosive electrolytes, are the subject of active research. Here we report a novel quinone-based aqueous redox flow battery employing inexpensive, stable and non-toxic electrolyte materials. The open circuit voltage is over 1.2 V, the peak galvanic power density exceeds 0.35 W/cm2, the membrane crossover rate is orders of magnitude lower than with inorganic redox couples, and capacity fade is less than 0.1% per cycle.
[1] B. Huskinson, M.P. Marshak, C. Suh, S. Er, M.R. Gerhardt, C.J. Galvin, X. Chen, A. Aspuru-Guzik, R.G. Gordon and M.J. Aziz, “A metal-free organic-inorganic aqueous flow battery”, Nature
505, 195 (2014), http://dx.doi.org/10.1038/nature12909
[2] B. Huskinson, M.P. Marshak, M.R. Gerhardt and M.J. Aziz, “Cycling of a quinone-bromide flow battery for large-scale electrochemical energy storage”, ECS Trans.
61, 27 (2014)
[3] B. Yang, L. Hoober-Burkhardt, F. Wang, G.K. Surya Prakash, and S.R. Narayanan, J. Electrochem. Soc.
161, A1371 (2014).
Neutron Radiography Applied to All-Vanadium Redox Flow Batteries for Side Reaction Detection
Authors: Clement Jason T. , Aaron Douglas , Hussey Daniel S , Jacobson David L , Mench Matthew M. 
Published: February 2020

Redox flow batteries are a technology of interest due to their potential for large-scale energy storage [1]. Recent progress has led to improvements in materials, performance, and stability; however much improvement is still possible. In order to make further progress, these systems must be understood at a more fundamental level. In situ diagnostic techniques provide deeper insight into the underlying mechanisms governing their operation and limitations. Such tools have proven useful in enhancing understanding of other electrochemical cells. One diagnostic tool that has been implemented for fuel cells is neutron radiography [e.g. 2,3].
Neutron imaging of fuel cells involves the detection of liquid water in a gas-phase cell. Since the neutron attenuation coefficient of liquid is significantly larger than that of gas phase, the identification of liquid water droplets in a gas-phase cell is straightforward. When applied to a redox flow battery however, reactants are in liquid phase, so the implementation is the exact inverse: gas-phase products generated within the cell will be detected by greatly reduced neutron attenuation.
For an all vanadium redox flow battery, undesirable side reactions between the liquid electrolyte and porous carbon electrodes or flow field plates can cause gas evolution. Currently, no published studies have attempted to experimentally determine conditions under which these side reactions begin to generate gas within an operating cell. This work address the implementation of neutron imaging as an in situ diagnostic technique to identify unfavorable operating conditions resulting in side reactions in vanadium redox flow battery systems. Figure 1 demonstrates the viability of this technique by illustrating that gas bubbles, identified by lighter colors, have been generated and detected within an all vanadium redox flow battery. Results from experiments at the National Institute of Standards and Technology Center for Neutron Research will be presented which show the bubble volume and onset of side reaction as a function of electrode materials and operating voltage.
1. A. Z. Weber, M. M. Mench, J. P. Meyers, P. N. Ross, J. T. Gostick and Q. Liu, Journal of Applied Electrochemistry, 41, 1137 (2011).
2. D. S. Hussey, D. L. Jacobson, M. Arif, K. J. Coakley, and D. F. Vecchia, Journal of Fuel Cell Science and Technology, 7, 021024 (2010).
3. A. Turhan, K. Heller, J. S. Brenizer, and M. M. Mench, Journal of Power Sources, 160, 1195–1203 (2006).

Figure 1
Comprehensive Impedance Analysis of Carbon Electrode Materials in Vanadium Redox Flow Batteries
Authors: Pezeshki Alan , Aaron Douglas , Tang Zhijiang , Zawodzinski Thomas A. , Mench Matthew M. 
Published: February 2020

Vanadium redox flow battery (VRFB) electrodes have been the subject of numerous studies, as they play a key role determining kinetic and mass transport losses within an operational battery1. Many studies have investigated modification of the electrodes through chemical and thermal treatments. These studies are typically confined to one type of electrode material. Enhanced performance is generally attributed to improved electrode kinetics or enhanced wettability.
Quantitative analysis of kinetic, ohmic, and mass transport losses is possible with electrochemical impedance spectroscopy (EIS), as Sun and coworkers have recently shown2. With this technique, the effects of electrode treatments on kinetics and mass transport can be resolved. In this work, a method by which to obtain noise-free low-frequency impedance data at flow rates much higher than the 1.5 mL min-1 by Sun and coworkers will be demonstrated. Fig. 1 shows the impedance-resolved losses of the negative electrode at a flow rate of 30 mL min-1.
The kinetics and mass transport overvoltages in carbon paper and carbon felt electrodes typically used in VRFBs will also be shown. Furthermore, the effects of chemical modification on both carbon paper and carbon felt will be shown; specifically resolving the effects of the treatments on both electrode kinetics and mass transport processes. A comparison of the ways in which specific treatments affect paper vs. felt will be discussed.

References

1. A.Z. Weber, M.M. Mench, J.P. Meyers, P.N. Ross, J.T. Gostick, Q. Liu, J. Appl. Electrochem., 41, 1137, (2011).
2. C.-N. Sun, F.M. Delnick, D.S. Aaron, A.B. Papandrew, M.M. Mench, T.A. Zawodzinski, J. Electrochem. Soc., 161, A981, (2014).
Figure 1.Impedance resolved losses on negative electrode in VRFB.

Figure 1
Engineering Chemical Functionality in Graphene
Authors: Hernandez Sandra Catalina , Sheehan Paul , Tsoi Stanislav , Dev Pratibha , Robinson Jeremy , Junkermeier Chad , Whitener Keith , Lee Woo , Reinecke Thomas , Walton Scott 
Published: February 2020

Graphene has attracted enormous attention due to its unique properties. Equally important is the ability to further tailor these properties through modification of select attributes such as surface chemistry, number of layers, sheet width, and edge structures. Manipulating the surface chemistry of graphene is important since the chemical composition strongly impacts the electronic properties as well as chemical reactivity both globally and locally. Precise control of the surface chemistry of graphene can also allow for subsequent surface procedures focused on band gap engineering, device fabrication and sensor applications. Given the strong impact of adsorbates, global chemical modification provides opportunities towards greater control over the properties of graphene films. Control over the spatial distribution of these groups provides an even greater functionality in that the local graphene reactivity can be manipulated, opening up a wealth of opportunities in biosensing, plasmonics, catalysis, smart surfaces, and heterojunction devices.
This work demonstrates the ability to manipulate the chemistry of graphene while regulating the spatial distribution of various functional groups on the surface. Spatial control over structural and chemical changes is characterized through micro (m-Raman and high-resolution x-ray photoelectron spectroscopy (XPS) mapping and electrical measurements are used to determine how local changes in chemistry influence the electronic properties. Lastly, we show that the resulting chemical moieties can be used to manipulate the local surface reactivity of graphene, enabling programmable, site-specific electrochemical deposition. These findings demonstrate the ability to tailor the locality of the surface chemistry on graphene surfaces opening up a wide range of reactivity studies and synthesis capabilities, such as programmable material deposition.
Intelligent Self-Healing Coatings: Investigating the Role of Self-Healing Kinetics at the Delaminating Interface
Authors: Rohwerder Michael 
Published: February 2020

The ultimate aim in the development of novel self-healing coating systems is to heal larger defects inflected into the coating reaching down to the metal, such as deep scratches. For this great amounts of self-healing agents have to be transported from the coating system to the defect site. This is a considerable challenge, especially since the self-healing agents to be stored in the coating system should safely stay inside it as long as they are not needed and they should still be available and active even after years of exposure. This requires reliable storage and very case-selective release mechanisms. At the same time, once the agents are released they should reach the defect site as fast as possible and in sufficient amounts. In many self-healing concepts found in the literature this is achieved by release through the coating surface. The transport to the defect site then occurs through the electrolyte. However, in most cases the self-healing coating will be covered by other coatings, such as e.g. for providing color or scratch resistance. Then the transport has to occur laterally. The best option for this is transport along the delaminating interface, as was recently shown for the release of inhibitors from conducting polymer based capsules incorporated in a PVB matrix [1, 2]. However, for really self-healing coating systems the transport of the active agents to the defect site will be impeded, if the delamination is stopped too early by a too fast self-healing at the interface before the defect site is healed [3]. First results of a more in-depth study of this problem will be shown. An important issue is to assess the degree of self-healing at the buried interface. For this a novel approach for studying the degree of interfacial degradation will be presented.
References
[1]A. Vimalanandan, L.P. Lv, T.H. Tran, K. Landfester, D. Crespy, M. Rohwerder

Redox-Responsive Self-Healing for Corrosion Protection

Advanced Materials 25(48) (2013) 6980-6984
[2]L.P. Lv, Y. Zhao, N. Vilbrandt, M. Gallei, A. Vimalanandan, M. Rohwerder, K. Landfester, D. Crespy,

Redox Responsive Release of Hydrophobic Self-Healing Agents from Polyaniline Capsules

J. Am. Chem. Soc. 135 (2013) 14198-14205
[3]T.H. Tran, A. Vimalanandan, G.Genchev, J. Fickert, K. Landfester, D.Crespy, and M. Rohwerder Regenerative Nano-Hybrid Coating Tailored for Autonomous Corrosion Protection

Advanced Materials, accepted
Electrical Resistance-Emission Spectroscopy for Determining the Electrochemical Behavior of Anodized Aluminum in Aqueous Solutions
Authors: Habib Khaled 
Published: February 2020

Holographic interferometry was utilized for the first time to determine the rate change of the electrical resistance of aluminum samples during the initial processes of anodization of the samples in aqueous solution without any physical contact. In fact, because the electrical resistance values in this investigation were obtained by holographic interferometry, electromagnetic method rather than electronic method, the abrupt rate change of the electrical resistance was called the electrical resistance –emission spectroscopy. The anodization process of the aluminum samples was carried out by the electrochemical impedance spectroscopy (EIS) test in different sulfuric acid concentrations (1.0–2.5% H2SO4) at room temperature. In the meantime, the real time holographic interferometry was used to determine the difference in the electrical resistance of two subsequent values, dR, as a function of the elapsed time of the EIS test for the aluminum samples in 1. 0, 1.5, 2.0 and 2.5% H2SO4 solutions. The electrical resistance–emission spectra of the present investigation represent a detailed picture of not only the rate change of the electrical resistance throughout the anodization processes but also the spectra represent the rate change of the growth of the oxide films on the aluminum samples in different solutions. Consequently, holographic interferometry is found to be very useful for surface finish industries, especially for monitoring the early stage of anodization processes of metals, in which the rate change of electrical resistance of the aluminum samples can be determined in situ.
Keywords: holographic interferometry; electrochemical impedance spectroscopy (EIS); anodization process; oxide film thickness; sulfuric acid; aluminum.
The Effects of Hydrophobic Coatings on an Insulative Skirt Layer to Decouple Galvanic Corrosion Between Mechanically-Coupled Aluminum Alloy and Carbon-Fiber Reinforced Polymer-Matrix Composites
Authors: Srinivasan Raghu , Hihara Lloyd H. , Nelson Jeffrey 
Published: February 2020

Lightweight metals such as aluminum (Al) are being frequently coupled to polymer-matrix composites (PMCs) to reduce weight and improve performance in a multitude of applications in the defense, aerospace, automotive and civil-infrastructure industries. The intimate contact of carbon-fiber reinforced (CFR) PMCs with Al alloys can result in galvanic corrosion of the Al alloys. The electrically conductive carbon fibers in the CFR PMCs serve as cathodes and induce galvanic corrosion of the Al.
The galvanic corrosion between 6061-T6 Al and CFR PMC can be effectively attenuated by decoupling Al from CFR PMC using an insulating skirt layer. The deposition of salts on the insulative skirt, however, can create a continuous ionically-conductive electrolyte film that can bridge the CFR PMC and Al, thus reducing the effectiveness of the skirt. The utilization of hydrophobic coatings on the skirt can help to attenuate galvanic corrosion by breaking up the continuous electrolyte film.
In this study, the effect of hydrophobic coatings on insulative skirt materials was investigated to attenuate galvanic corrosion between mechanically coupled 6061-T6 Al and CFR PMC. Experiments were conducted in accelerated laboratory and outdoor conditions. The galvanic corrosion rates were monitored for coatings of different degrees of hydrophobicity, various skirt lengths, and exposure conditions and.
Initially, the galvanic corrosion rates for couples with different insulating-skirt lengths coated with a silane-based ceramer (i.e., Siloxel) were monitored in a humidity chamber at 30o C and 90% RH over a period of up to 3 days using the zero resistance ammeter (ZRA) technique. The couples were sprayed with salt solutions of different concentrations. Results from this accelerated humidity ZRA experiment showed that a skirt length of only 0.5 inch was very effective in attenuating galvanic corrosion. To study the effectiveness of different coatings, specimens were fabricated with a 0.5-inch long skirt and coated with either Siloxel, epoxy, polyurethane or latex. The resulting galvanic corrosion rates were then compared.
The two best coatings in attenuating galvanic corrosion (i.e., Siloxel and polyurethane) were selected for outdoor exposure. CFR PMC/Al galvanic couples with 0.5 inch insulating skirts (with either the Siloxel or polyurethane coatings, or no coatings) were exposed at rain forest (Manoa) and severe marine (MCBH) environments for 2 months. The CFR PMC/Al galvanic specimens at the severe marine site were exposed in two conditions: sheltered and unsheltered. The sheltered specimens were subjected to significant salt build up; whereas, the unsheltered specimens were subjected to cleansing effects of rain. The effect the salt deposition characteristics on galvanic corrosion between the sheltered and the unsheltered conditions was studied.
(Invited) Inhomogeneity of Barrier Layer Inducing Irregularity of Porous Anodic Oxide Film on Aluminum
Authors: Ono Sachiko , Asoh Hidetaka 
Published: February 2020

Porous anodic oxide films formed on various metals, especially anodic alumina, have attracted huge attention as a starting material in the fabrication of nano-devices because of the high controllability of porous structures in nanometer scale such as pore size, pore interval, as well as pore depth by changing electrolysis condition in addition to their high regularity of pore arrangement. In recent years, mechanism of self-ordering of anodic alumina films has been intensely studied. We proposed anodizing under high electric field strength as a key factor for self-ordering of pore arrangement (1). However, only a few reports are found on the mechanism of irregularity or defects formation of porous anodic oxide films. For example, an regular deposition of metals into all anodic pores are often difficult because of irregularity of the barrier layer. In the case of anodic films formed on aluminum in chromic acid solution, for example, sever pore blanching appears especially at the higher voltage. Anodic alumina films formed in phosphoric acid and Ematal bath also indicates numerous pore branching and caved pores in the cell wall (2, 3) where anodizing conditions such as high formation voltage and relatively low dissolution ability of electrolytes to anodic oxides are used. These irregularities were caused by defects/holes induced by electric breakdown between pore bottom and protrusion at triple points of cell boundary. Impurity elements in metals and alloys also bring defects and irregularity into porous structures. Furthermore, anodic films formed at some specific condition, especially on titanium, yielded tubular structure having interspaces at cell boundaries. All of these irregularities should be created only at the barrier layer grown under the anodic field by specific reactions other than stable anodic oxide growth. This inhomogeneity of barrier layer such as unevenness of the thickness and voids that induce irregularity in porous oxide seems to be playing an important role at an application for industry both in a positive and negative way. In this paper, we report the specific futures of irregularity appeared in porous anodic oxides films formed on aluminum and evaluated to get unified formation mechanism of such imperfections to be induced in the oxides grown on various substrates.
[1] S. Ono, M. Saito, M. Ishiguro and H. Asoh, J.Electrochem. Soc., 151, B473 (2004).
[2] S. Ono, H.Ichinose and N. Masuko, J.Electrochem.Soc.,
138, 3705 (1991)
[3] S. Ono and N. Masuko, J. Jpn Inst. Light Metal,
43, 453 (1993).
Electrochemical and Thermal Contributions to Ultra-Deep AAO Growth: Aspect Ratio >104
Authors: Solomon Mitchell L , Schwartz Nicholas R , Cox Philip , Hill Justin J 
Published: February 2020

Self-ordered anodic aluminum oxide (AAO) nanopores is the focus of intense research for many diverse fields including photocatalysts, electrochemical energy storage, thermoelectrics, and optics. Furthermore, the self-ordering of densely packed pores serves as an ideal template for 1-D nanostructure fabrication. Currently, hard anodization has achieved the highest growth rates (50 – 100 μm h-1) to >1000 aspect ratio1, but no further research has been presented on extended depth regimes. Technical and economic success of many of these technologies, is dependent on fast fabrication of ultra-high aspect ratio (>104) AAO arrays. We present here the high-speed growth of AAO pores with ultra-high aspect ratios achieved by balancing the thermal and electrochemical physics of pore ordering during initiation and extended steady-state growth rate.
Effective management of reaction and joule heating is paramount to achieving self-ordering and preventing thermal failure of AAO during pore initiation. Traditionally, slow ramp rate (1 v/s), low concentration (~0.05M), and low electrolyte temperature (~0°C) conditions have been used to prevent initial thermal failure of potentiostatic anodizations at the cost of well-defined pore ordering. However, recent studies have shown that thermal control of the working electrode is much more effective than chilling the electrolyte2. The effect of direct potential application with sufficient heat removal by electrode cooling is discussed.
Furthermore the effect of temperature was studied to optimize the rate of hard anodization at steady-state. During steady-state, isothermal anodization rate decays exponentially as a function of time making the rate infeasible to economical production of deep arrays. Electrode temperature step experiments were conducted and its effect on steady-state anodization rate is discussed.
Long-term, isothermal anodizations exhibit a radial distribution of pore lengths with pore lengths decreasing with increasing radial dimension, resembling a cone structure. This effect is unfavorable as it suggests a non-ideal distribution of current thus complicating the geometry of the array. Forced ideal current distribution and its effect on extended depth anodizations is discussed. Additional technical hurdles and the results of these tests will be presented.
1. Lee, W., et al., Fast Fabrication of Long-Range Ordered Porous Alumina Membranes by Hard Anodization. Nature Materials
2006,
5 (9), 741.
2. Aerts, T., et al., Control of the Electrode Temperature for Electrochemical Studies: A New Approach Illustrated on Porous Anodizing of Aluminium. Electrochemistry Communications
2009,
11 (12), 2292.