bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Mn-Based Cathode for Energy Dense Zn-Anode Batteries
Authors: Yadav Gautam Ganapati , Huang Jinchao , Turney Damon , Hawkins Brendan , Nyce Michael , Banerjee Sanjoy 
Published: February 2020

Research interest on zinc (Zn)-anode aqueous-based batteries have renewed recently because of its low equilibrium potential in aqueous electrolyte, low cost, non-toxic and nonflammable characteristics compared to lithium-ion batteries. Zn has a high theoretical capacity of 820mAh/g based on two electron reactions, thus it has the capacity to deliver high energy density if it is paired with an equally high capacity cathode. Silver and nickel are high capacity cathodes; however, they are very expensive and require the addition of expensive additives like cobalt in nickel to increase the rate of the battery. MnO2 is the best cathode to be paired with Zn because it has a high two electron capacity of 617mAh/g and it is extremely safe and economical. Recently, we showed that attaining the two electron capacity of 617mAh/g for over 3000 cycles was possible with the used of bismuth and copper additives. Energy densities >160Wh/L were attainable when the cathodes were paired with Zn at 15% utilization.1-4 However, they are still susceptible to Zn poisoning which lead to the formation of inactive phase called haeterolite (ZnMn2O4). To improve the energy densities of Zn-anode batteries new inexpensive and safe cathodes with higher capacity than MnO2 and increasing Zn utilizations to >20-25% are a must.
In this presentation, we will report the synthesis of a new Mn-based cathode that delivers capacity ~800mAh/g, which is almost comparable to the Zn anode theoretical capacity. This new Mn-based cathode is able to deliver its capacity at high rates and maintain its capacity at high cycle life. We will present the reaction mechanism of this Mn-based cathode through real time microscopy videos and images, high resolution transmission microscopy and electroanalytical methods. We also report on the use of new Zn-based anodes that utilize >20% of its theoretical capacity and, at the time of this writing, still cycle with much deterioration in capacity due to shape change or passivation. The combination of the new high capacity Mn-based cathode and high utilization Zn-based anode results in a cell that delivers energy density >200Wh/L.

Funding:

This work was supported by the New York State Research and Development Authority (NYSERDA) under Project Number 58068.

References:

1] Yadav, G. G.; Gallaway, J. W.; Turney, D. E.; Nyce, M.; Huang, J.; Wei, X.; Banerjee, S., Nat. Commun., 2017, 8, 14424
2] Yadav, G. G.; Wei, X.; Huang, J.; Gallaway, J. W.; Turney, D. E.; Nyce, M.; Secor, J.; Banerjee, S., J. Mater. Chem. A, 2017, 5 (30), 15845-15854
3] Yadav, G. G.; Wei, X.; Gallaway, J. W.; Chaudhry, Z.; Shin, A.; Huang, J.; Yakobov, R.; Nyce, M.; Vanderklaauw, N.; Banerjee, S. Materials Today Energy, 2017, 6, 198-210.
4] Yadav, G. G.; Wei, X.; Huang, J.; Turney, D.; Nyce, M.; Banerjee, S. International Journal of Hydrogen Energy, 2018, https://doi.org/10.1016/j.ijhydene.2018.03.061
Standard Hydrogen Electrode Potential Referenced to Inner Potential from Density Functional + Implicit Solvation Theory
Authors: Haruyama Jun , Ikeshoji Tamio , Otani Minoru 
Published: February 2020

Electrode potential is a general concept, in electrochemistry, which governs the charge transfer reactions such as ion insertion/extraction and reduction-oxidation at electrode/solution interfaces; the electrode potential should be appropriately included in the computational model. In this study, we consider how the standard hydrogen electrode (SHE) potential, which is the equilibrium potential of the charge transfer reaction of H+/H2, is theoretically evaluated.

Methods

We employed density functional theory (DFT) calculations combined with the effective screening medium (ESM) technique1 + the reference interaction site method (RISM);2 ESM-RISM formulation3 makes it possible to simulate the electrode (+ reactive ions) and the solution based on quantum mechanics and implicit classical solvation model, respectively. ESM-RISM calculations were performed on the configuration of a vacuum/slab/solvent system as shown in Figure 1, where the DFT slab domain is on the left-hand side, and the RISM solvents, that is, H2O, H3O+, and Cl− treated by the RISM equations, are on the right-hand side. Changing the chemical potential of electron, µ
e, referenced to the inner potential ΦS at the bulk solution region, we compared the grand potentials Ω for the following reaction R:
H3O+ (1M HCl aq.) + e− (electrode M, M=Pt, Al) ↔︎ 1/2 H2 (gas) + H2O (1M HCl aq.) (R).

Results

ESM-RISM calculations revealed Ω of the left side state of reaction R and that of the right state on Pt(111) electrode. They cross at µ
e = −5.27 eV, which is equilibrium chemical potential of electron at SHE reaction (= µ
SHE). This indicates that the electrode potential vs. SHE, E(SHE), is evaluated as E(SHE) = −(µ
e − µ
SHE)/e. We also obtained the almost same value of µ
SHE on Al(111) electrode. On the other hand, Pt(111) and Al(111) is negatively and positively charged at µ
e
=
µ
SHE, respectively. In the presentation, we will compare the potential profile of metal/solution/vacuum region obtained from ESM-RISM and the first-principles molecular dynamics calculation using ESM.4 We further discuss on the difference between µ
SHE and the absolute SHE obtained by Trasatti.5

References

M. Otani, O. Sugino, Phys. Rev. B
73, 115407 (2006).

F. Hirata, P. J. Rossky, Chem. Phys. Lett.
83, 329, (1981).

S. Nishihara, M. Otani, Phys. Rev. B
96, 115429 (2017).

M. Otani, I. Hamada, O. Sugino, Y. Morikawa, Y. Okamoto,T. Ikeshoji, J. Phys. Soc. Jpn.
77, 024802 (2008).

S. Trasatti, Pure Appl. Chem.
58, 955 (1986).

Figure 1
Galvanic Corrosion between AA5052 Aluminum-Magnesium Alloy and SS400 Carbon Steel in Aqueous NaCl Solutions
Authors: Ota Kengo , Tada Eiji , Ooi Azusa , Nishikata Atsushi 
Published: February 2020

Aluminum alloys (AAs) such as 5000 and 6000 series have relatively good corrosion resistance and plastic workability. The use of these alloys for automobile body parts have been increased significantly because of reducing the weight of the body and improvement of fuel consumption. Although aluminum alloys themselves have relatively good corrosion resistance in atmospheric environments, galvanic corrosion between aluminum alloys and other materials should be taken into consideration in automotive application. This is because the body parts made of Al alloys should be jointed with other materials such as steel parts by welding or other methods and because the jointed parts can be exposed to atmospheric corrosion environments. In this study, galvanic corrosion between AA5052 aluminum-magnesium alloy and SS400 carbon steel is investigated in aqueous NaCl solutions.
A galvanic couple used in this study was made of AA5052 Al-Mg alloy (Mg: 2.65, Si: 0. 08, Fe: 0.27, Cu: 0.01, Cr: 0.17, Zn: 0.01, Al: bal. (mass%)) and carbon steel (JIS SS400). The plate of both materials was 10-mm width and 15-mm length and 3-mm thickness. After lead wire was connected on the surface of the plates, they were embedded in an epoxy resin. At this time, both materials were separated with a 500-um gap. The surface of the galvanic couple was polished with SiC papers up to JIS 2000 grit and rinsed in EtOH. Galvanic corrosion experiments were performed for 2 hours in aqueous NaCl solutions at various concentrations ranging from 5 mM to 500 mM. Galvanic current and corrosion potential of the couple were measured during the immersion in the solutions.
Corrosion potentials measured during the immersion in various concentrations of NaCl were almost constant for 2 h. The corrosion potentials changed in the less noble direction with increasing NaCl concentrations. Galvanic currents between AA5052 and SS400 showed positive values during the immersion in the solutions, indicating that aluminum-alloy side was basically an anode. However, the galvanic currents were almost the same independent of NaCl concentrations. From the results of polarization behaviors for AA5052 and SS400, a significant anodic current increase due to the propagation of localized corrosion on aluminum alloy and a diffusion-limiting current for the reduction of dissolved oxygen on steel were observed at the corrosion potentials of the galvanic corrosion tests. These results indicated that galvanic corrosion between AA5052 and SS400 in the early stage of immersion progressed under a diffusion-limiting condition for the reduction of dissolved oxygen on steel.
(Corrosion Division Morris Cohen Graduate Student Award) Local Hydrogen Detection Techniques for Atmospheric Uptake in Ultra-High Strength Steels
Authors: Schaller Rebecca Filardo , Thomas Sebastian , Birbilis Nick , Scully John R. 
Published: February 2020

Hydrogen embrittlement (HE) is a concern specifically in ultra-high strength steels (UHSS) prevalent in key structural and vehicle components. In full immersion environments, hydrogen production and uptake in high strength materials has been well documented, such as in the case of cathodic protection. However, for atmospheric exposures, there is a large lack of information regarding hydrogen production and uptake. Under atmospheric conditions, acidic pits can form in UHSS due to the breakdown of the passive film, metal dissolution, hydrolysis, and acidification which are prone to local H production and uptake. An understanding of the effects of marine aerosols, industrial pollutants, and other environmental factors, such as UV and relative humidity, on hydrogen production and uptake in UHSS is necessary to develop new alloys with improved corrosion resistance as well as to anticipate and manage the effects of environment severity on embrittlement susceptibility of currently employed UHSS.
However, at present, the majority of available techniques for the measurement of hydrogen dissolved in metals and effective hydrogen diffusivity (DH,eff) lack spatial resolution at the micrometer scale. This is not only of significance for atmospheric exposures, with localized H uptake occurring at pits and/or within droplets, but is also of great importance since the hydrogen-metal interactions and processes occurring at the micrometer to nanometer length scales govern hydrogen embrittlement (HE). This presentation discusses and demonstrates select novel local hydrogen probes; the Scanning Kelvin Probe (SKP) and the Scanning Electrochemical Microscope (SECM). The detection of the spatial distribution of diffusible H concentrations was demonstrated on pre-exposed metallic surfaces with the SKP and SECM. SKP and SECM scans of H uptake in samples from controlled atmospheric pre-exposures are also presented. The application of these techniques is shown to provide local and spatial information on H concentrations produced through atmospheric corrosion. An understanding of the H severity at this local scale can provide significant information on severity of atmospheric exposure environments in terms of H production, uptake, and transport. Furthermore these techniques are adaptable to even higher resolution measurements with the application of the SKP atomic force microscope (SKPFM) or SECM-AFM.

Acknowledgement:

Research was sponsored by the US Air Force Academy under agreement number FA7000-13-2-0020 and ONR under PROJ0007990. The authors would like to acknowledge the Army Research Laboratories, as well as Monash University, in particular Dr. Sebastian Thomas and Prof. Nick Birbilis. The research was partially supported by a 2014 Australia Endeavour Award Research Fellowship with support from Dr. Kishore Venkatesan and Dr. Ivan Cole at CSIRO.
Ascorbic Acid as Antioxidant
Authors: Agrisuelas Jeronimo , Cuenca Alejandro , García Jose , Vicente Francisco 
Published: February 2020

The use of ascorbic acid as a food additive is well known in health fields because it is a natural substance that is present in many fruits and vegetables, especially citrus fruits. Its beneficial actions in living beings is frequently associated with its inhibitory action of oxidative biochemical processes. On the other hand, it has also been found to inhibit the corrosion of metal alloys despite the fact that the metals in contact with acidified aqueous media react with the hydrogen ions to give molecular hydrogen and metal derivatives.
When checking in our laboratory that the juice of different citrus fruits and solutions of ascorbic acid and citric acid cause this effect on different technological metals and also check the protective action of ascorbic acid on the superficial atmospheric oxidation of carbonaceous particles, such as those of graphene or graphite, the idea arose to analyze the inhibitory effect of the anodic solution of a known system easy to study using electrochemical techniques that could be model of the inhibitory mechanism caused by ascorbic acid. In this work the inhibitory effect of ascorbic acid on copper anodic dissolution is studied by means of spectrum-electro-gravimetric techniques, since the Cu / acid solution system is a relatively simple model of possible utility to interpret the inhibitory effect of ascorbic acid on other more complicated systems.
The spectro-electro-gravimetric studies are useful to explain the corrosion and electrodeposits kinetics of copper in acid media [1,2]. If we analyze the mass evolution at open circuit potential of copper in sulfuric and ascorbic media, it is showed that in the chase of sulfuric media the mass decreases, but the process is slower at the end attending to the passive layer formation. However, when we analyze the mass evolution for the ascorbic acid dissolution, we can see that the mass grows proportionally to the acid concentration. First, takes place the adsorption on non-charged species over the electrode surface. This fact increases the rigidity over the electrode surface decreasing the values of the motional resistance. When the electrochemical process begins, there is an accumulation of copper ions over the electrode surface. The accumulation of copper ions allows the catalytic oxidation of the ascorbic acid.
1) D. Giménez-Romero, C. Gabrielli, J.J. García-Jareño, H. Perrot, F. Vicente Electrochemical quartz crystal microbalance study of copper electrochemical reaction in acid medium containing chlorides,. J. Electrochem. Soc. 153 (2006) J32-J39.
2) A. Cuenca, J. Agrisuelas, J.J. García-Jareño, F. Vicente, Oscillatory Changes of the Heterogeneous Reactive Layer Detected with the Motional Resistance during the Galvanostatic Deposition of Copper in Sulfuric Solution, Langmuir.31(46) (2015) 12664-12673.
Arrays of Permanent Nanomagnets Produced By Bi-Metal Deposits within Nanostructured Silicon
Authors: Rumpf Klemens , Granitzer Petra , Gonzalez-Rodriguez Roberto , Coffer Jeffery , Poelt Peter , Michor Herwig 
Published: February 2020

This work presents the investigation of the magnetic behavior of bi-metal nanostructures within nanostructured silicon with the aim to exploit the magnetic properties of both metals and gain control of the exchange coupling between the two metals especially with respect to their volume ratio. Furthermore a variation of the structure size and the proximity of the metal deposits modify the exchange coupling and thus the energy product. Finally nanocomposite systems with an energy product as high as possible are achieved to give rise to on-chip applications using permanent nanomagnets, especially arranged in arrays.
Magnetic nanostructures of two different metals are deposited within nanostructured silicon to control the magnetic switching behavior of the silicon/metal nanocomposite. Two different templates, porous silicon and porous silicon nanotubes are utilized to achieve such nanocomposites. The morphology (pore diameter, tube diameter) of the two systems is comparable. In the case of the utilization of porous silicon templates a mesoporous morphology with average pore diameters of 50 nm is used and these oriented and separated pores are filled with two different metals, namely Ni and Co. The two metals are deposited alternatingly by electrodeposition. A further approach is the chemical growth of Co nanoparticles within porous silicon nanotubes (SiNTs) and the additional deposition of a Ni layer on the outer surface of the tubes. The inner diameter of the silicon tubes is around 50 nm and the wall thickness is about 10 nm. Since the silicon wall of the tubes offers a porous structure the Co particles, which are localized near the pore surface on the wall of a given nanotube, can touch the Ni layer. An alternative structure involves the deposition of an additional Si layer (after the growth of Co particles inside the tubes) as a spacer before the Ni deposition.
The morphology of the deposited bi-metal Ni/Co structures is figured out by SEM and EDX.
In the presented work the dependence of the magnetic properties of a nanostructured silicon/bi-metal nanocomposite on the volume ratio of the metals, on the proximity of the nanostructures and also on the size of the metal deposits has been figured out. If the distance between the deposited bi-metal structures is small enough magnetic exchange coupling between them is present which could be observed. By tuning the bi-metal deposition an optimized energy product is achieved which gives rise to self-assembled nanocomposite systems containing permanent nanomagnets and arrays of them, respectively for on-chip applications.
Nanopore-Organized Nanoparticle Arrays for Tunable Optical Materials Using Nanobioplar Electrodeposition
Authors: Crouch Garrison , Han Donghoon , Fullerton Susan , Go David B. , Bohn Paul W. 
Published: February 2020

The combination of polymers with nanopores has been of interest recently in many areas, from polymer-hybrid nanotube materials to functionalized membranes. Tightly-controlled nanopore arrays fabricated via Focused-Ion Beam (FIB) have demonstrated advantages in isolating small numbers of molecules or nanoscale objects, as with single molecule electrochemistry, and are well-suited to further engineering including multiple electrode rings and advanced surface functionalization techniques.
In this work, we discuss the ability of nanopore arrays to create ordered polymer cylinder arrays for testing the formation of nanofilaments in constrained polymer conditions as well as bipolar electrodeposition using nanoparticles. Previous work examined the kinetics of nanoscale bipolar electrodeposition by creating conductive filaments through a single nanoparticle, which demonstrated unique behavior due to the inherent limitations of nanoscale mass transport. Bipolar electrochemistry has demonstrated advantages in examining electrochemical effects under high electric fields, optically-coupled experiments, and other geometries where conventionally-connected electrodes would be prohibitively complex. In macro-scale bipolar electrochemistry, the difference in electric potential between the electrode and the surrounding electrolyte provides the driving force for a chemical reaction, such as the deposition of a metal ion from solution onto a surface. If that deposition is suitably controlled, a conductive filament may be created by electrodeposition, for example, in a nanoscale gap between two electrodes to create an atomic-scale junction.
This work examines the connection of multiple nanoparticles constrained in a nanopore array via the creation of conductive filaments, and the resultant change in optical behavior due to modified nanoparticle plasmonics. Preliminary theory suggests that the optical permittivity of the nanoparticle array may be tuned via formation and dissolution of the filaments. With application areas ranging from massively-parallel chemical sensing arrays to non-contact tunable metamaterials, this work uses advanced nanopore arrays to further the mechanistic understanding of nanoelectrodeposition and explore the unique challenges involved, both aspects vital to advancing the use of similar technology in real-world devices.
Special thanks to the Defense Advanced Research Projects Agency (DARPA) FA8650-15-C-7546 and the NASA Space Technology Research Fellowship (NSTRF) NNX16AM45H for providing funding for this research.
Ex-Situ Evidence on the Transition of Anodic Nanopores into Nanotubes Formed on Iron
Authors: Shahzad Khurram , Fadillah Laras , Kowalski Damian , Zhu Chunyu , Aoki Yoshitaka , Habazaki Hiroki 
Published: February 2020

Anodizing is a high voltage electrochemical conversion process that forms barrier-type oxide layers or self-organized nanoporous/nanotubular structures. So far, the Al2O3-like nanopores and TiO2-like nanotubes could be successfully synthesized on many valve metals and alloys. The proposed models of anodic oxide nanotubes growth, however, sacrifice from lack of evidence on the transition from nanopores to nanotubes. Recently, anodizing become possible for more oxidizable metals such as iron and its alloys. The challenge in anodizing of iron lies in the proper control of corrosion/passivity of iron which can be successfully realized in organic electrolytes containing small amount of water. 1-3

Herein, we investigate the origin of the growth of nanotubes on iron in ethylene glycol electrolyte containing ammonium fluoride and desired amount of water. The composition of the nanoporous/ nanotubular anodic films formed on iron at various water concentrations is examined by high resolution electron microscopy/EDS elemental mapping.
The anodizing of iron in organic electrolytes containing fluorides typically leads to formation of nanopores and nanotubes depending on anodizing voltage. The kinetics of transition from nanopores to nanotubes is relatively slow for iron oxide and therefore allows for ex-situ observation of metal-fluoride layer upon nanopores/nanotubes transition. The TEM image shows pseudoporous structure in which anodic oxide is surprisingly in the form nanotubes as demonstrated by corresponding compositional TEM/EDS mapping. 4 The oxide nanotubes are separated by metal fluoride matrix which dissolves during anodizing process. The presented compositional fingerprints of the transition of nanopores into nanotubes are an evidence on the role of fluorides in the growth of anodic nanotubes.
References:

H. E. Prakasam, O. K. Varghese, M. Paulose, G. K. Mor and C. A. Grimes, Nanotechnology, 2006, 17, 4285-4291.

H. Habazaki, Y. Konno, Y. Aoki, P. Skeldon and G. E. Thompson, Journal of Physical Chemistry C, 2010, 114, 18853-18859.

Y. Konno, E. Tsuji, P. Skeldon, G. E. Thompson and H. Habazaki, J. Solid State Electrochem., 2012, 16, 3887-3896.

K. Shahzad, D. Kowalski, C. Y. Zhu, Y. Aoki and H. Habazaki, Chemelectrochem, 2018, 5, 610-618.

Figure 1 Bright field TEM micrograph for FIB cross-section of anodic iron formed at 100V in ethylene glycol electrolyte containing 1.5M H2O and 0.1M NH4F. The corresponding EDS maps show the elemental distribution of oxygen (green) and superimposed fluorine (red) and oxygen (green).

Figure 1