bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphology Controlled Fabrication of Nanostructured Molybdenum Oxides By Different Mineralizers Via Hydrothermal Synthesis Method
Authors: İnel Eren , Karahan Billur Deniz 
Published: February 2020

Recently, the “chemistry of form” turns into an interesting subject for scientists of various disciplines. Thus, designing novel structured materials and controling their morphologies become an attractive and value-added research topic. Among alternative materials, molybdenum oxides have been researched in depth as they find a large variety of applications in electrochemistry. The evaluation of molybdenum oxide as anodes for Lithium Ion Batteries (LIBs) is an example for their various applications. Their higher discharge capacity (over the state-of-the-art anode, graphite) revealed upon cycling makes them a strong candidate for being the anode material of next generation LIBs.
So far, solid state reactions at temperatures up to 1000 °C, ball-mill, co-precipitation, sol-gel synthesis and hydrothermal processes have been used in the production of molydenum oxides.
In this study, hydrothermal method being environmental friendly process is chosen as production method due to its low investment cost, practical application and good control over the crystal structure as well as the morphology of the particles. Although, previously the effect of different mineralizers on the particle morphology has been studied a comparitive study based on investigating the effect of same cationic based mineralizers on the particule properties has not been done yet.
In this work, first in literature, three different sodium based mineralizers (sodium nitrate, sodium chloride and sodium acetate) has been added into the ammonium heptamolybdate (AHM) precursor solution, separetly (pH=0), and their effects on the crystal structure and morphology of molybdenum oxide particles have been investigated. Among alternatives mineralizers, alkali chemicals stand out as cationic ions are expected to be the most influencing factor on the nucleation and growth of molybdenum oxide particles. During the experiments, the hydrothermal reaction takes 12 hours and the temperature is set to 1800C. The resulting powders’ surface morphologies are analyzed by secondary electron microscope, and their structures are characterized based on X-ray Diffraction method. The results are used to propose a nucleation and growth mechanism of molybdenum oxide particles during the hydrotermal treatment, in the presence of different sodium based mineralizers. The possible use of the resulting molybdenum oxides as anode materials for lithium ion batteries has been also discussed based on electrochemical tests.
(Invited) Model Guided Design and Analysis of Experiment
Authors: Brady Nicholas W , Mayilvahanan Karthik , West Alan C 
Published: February 2020

Batteries are complex, with phenomena emanating from multiple length scales that may impact performance and life. Advances thus require multiscale experimental inquiries, and mathematical models, including multiscale models, may be employed to design, analyze and integrate studies. In early-stage research efforts, close collaboration with experimental efforts may result both in dramatically improved model fidelity and in more optimal utilization of experimental resources.
We present approaches to augment physics-based models of Li-ion cathodes with applied statistics algorithms based on Markov-chain Monte Carlo simulations. Several examples are illustrated. The use of model regularization algorithms as a tool to efficiently introduce new physics in cathode-performance and degradation models is demonstrated. Additionally, model selection algorithms are demonstrated within the context of studies of mesoscale transport processes. Identification of the better model leads to an understanding of the dominant length scale in terms of impedance. Such tools can inform decisions in terms of where to focus experimental resources. Finally, the model-guided design of experiment (MGDOE) is discussed. Specifically, the use of simulation tools to identify experimental approaches to minimize parameter uncertainty is discussed, and the use of MGDOE for synchrotron-based operando experiments is considered.
(Invited) Effect of Gravitational Level on the Initial Stage of Cu Electrodeposition
Authors: Fukunaka Yasuhiro 
Published: February 2020

Material tailoring of nanostructured devices emphasizes the importance to separately control the nucleation rate from the growth process. It is indispensable to uniquely create the heterogeneous interface to result in the required electronic or physical properties. Then, the multi-scale modeling to link the atomic scale process on the heterogeneous interface with the shape evolution phenomena based on the continuous media process is required.
It is well known that natural convection is accompanying with physicochemical reactions under ground level (1 G).　Microgravity experiments are conducted over 10 s with JAMIC drop tower in order to understand the effect of gravitational level on electrodeposition as well as electrochemical dissolution. Less nucleation rate was observed in μ-G. On the other hand, a centrifugal field has been applied widely in order to create high G environment in electrochemical processing. Various differences in physical and chemical properties were found as well as morphological variations.
The main purpose of this study is to clarify the effect of gravitational level from m-G to high G level on the coupling phenomena between the ionic mass transfer rate and the morphological variations of the electrodeposits. The possibility to control the nucleation phenomena, film morphology and nanostructure is explored.
In particularly, the effects on the electrodeposited copper are analyzed in a cavity-type electrolytic cell from microgravity field in parabolic flight to high G field in centrifugal field. Cathode over anode configuration simulates the ionic mass transfer rate under quasi-microgravity environment because no macroscopic natural convection is induced in this cell configuration. Copper electrodeposition is conducted in order to examine the nucleation rate of copper on TiN substrate. The effects of cell configuration and gravitational level are focused on these phenomena.
Cyclic Voltammetry of Ge and Te in Basic Conditions: An Investigation of Surface Coverages.
Authors: Sisk Peter W , Stickney John Lewellen 
Published: February 2020

Cyclic Voltammetry of Ge and Te precursors in basic solution can lead to a better understanding of the surface limited reactions taking place at the substrate-solution interface. GeTe is a phase-change chalcogenide material with excellent stability for the crystalline and amorphous phases. The stoichiometry of the film is very important as the 1:1 compound is shown to have the highest switching rates.1 Controlling the stoichiometry has proven to be difficult using conventional methods, so in this study, deposition conditions for stoichiometric GeTe are sought using Electrochemical Atomic Layer Depostion (E-ALD). EALD is a process developed by this author’s lab which makes use of underpotential deposition (UPD) to put down fractions of a monolayer of the desired material. This process can then be repeated for as many cycles as are needed to grow films of the desired thickness. Before a deposition sequence can be made, the interactions of the individual elements must be investigated, both on the substrate, and on each other. This is achieved through the use of cyclic voltammetry, which measures the current generated as each element is either deposited or stripped from the surface as a function of electrochemical potential. By quantifying the current, the number of deposited or stripped atoms can be calculated, giving an estimate of the surface coverage. Investigations have identified the surface limited and bulk potentials for each element on the substrate as well as their substrate coverage. The next step will be to develop a sequence using these potentials to develop high quality, epitaxial films.
References:

Physical Review B. 2006, 73, 045210.
(Invited) Simulation of CdSe Based Quantum Dot Hybrid Light Emitting Diodes Using Tcad Continuous Models
Authors: Grassi Roberto , Arroyo Iker , Iniguez Benjamin , Drevon Tark , Plews Andrew , Chourou Slim , Townsend Mark , Nejim Ahmed 
Published: February 2020

Organic-inorganic hybrid quantum dot (QD) based light emitting diodes (LEDs) have been investigated. Stacked hybrid QD LED structures, based on cadmium selenide QD with cadmium sulfide barrier shells, have been fabricated at the Universtiat Rovira i Virgili using spin coating techniques. These have been modelled, with Technology Computer Aided Design (TCAD) software, using two different carrier conduction models.
Two quantum confinements models are used to predict the electronic transport through these stacks. A 1D simulation of a stack with a single QD mono-layer, using the Silvaco Radiant tool based on the Atlas engine, is reported. This approach allows device designers to optimise the current density and spectral response as a function of QD radius (as shown in the figure) and transport layer thicknesses. Furthermore, a second approach using a 3D QD simulation in which the user can investigate the effect of the QD radius and barrier layer thickness on the carrier confinement in the structures is shown.
This work demonstrates the capability of 1D simulations, using the Radiant software tool, to model the behavior of single QD mono-layer structures. The user friendly input graphical user interface, as well as the speed of the simulation, helps to iterate the design quickly to optimise QD size and transport layer thicknesses for maximum intensity at the desired spectral output.

Figure 1
Rheological Study of Micro Porous Layer and Its Effect on Transport Properties in a PEMFC
Authors: Mehrazi Shirin , Chuang Po-Ya Abel 
Published: February 2020

Technical challenges related to catalyst flooding in a polymer exchange membrane fuel cell (PEMFC) have led to various studies to improve water management through evolutionary gas diffusion layer (GDL) design[1] [2].It has been well established that a GDL consisting of a macro-porous substrate coated with a hydrophobic microporous layer (MPL) has an indispensable role in gas and water transport [3]. However, a fundamental understanding of the MPL role and its optimal composition and structure are still lacking. Currently, the most widely used MPL in a PEMFC is made from ink dispersion that consists of carbon, PTFE, and solvent. Before MPL optimization is possible, the desired properties of the MPL ink dispersion and its interaction with the macro-porous substrate needs to be studied. In this study, we used rheological measurements as an evaluation tool to study a baseline MPL ink with Acetylene Black (AB) and PTFE. Specifically, we performed intensive rheological experiments to study the following three properties of the MPL ink: 1) flow properties, like viscosity, through continuous ramp rate, 2) viscoelastic properties through cyclical sweeping method, and 3) transient properties through recovery and relaxation measurement. Our preliminary results show that the ink stability, size of the primary agglomerate, viscosity, viscoelastic property, and creep recovery are strongly influenced by carbon to PTFE ratio and the weight percentage of the solid content. Built on the foundation of our previous work, we expand our study to include two types of carbon materials, AB and Carbon Nano Tube, three PTFE/Carbon ratios (20%, 30%, and 40%), and two solvent ratios (IPA rich and water rich) in this study. Standard Toray-H-060 substrate with 20% PTFE is used as the baseline macro-porous substrate and the MPL ink is applied directly onto the substrate by rod coating. The GDL is then dried and sintered accordingly. Both ex-situ evaluations, such as surface roughness, hydrophobicity, coating quality, and MPL penetration, and in-situ fuel cell testing are performed to study the effect of MPL on transport and performance under both wet and dry conditions. Our results provide new insights to enhance transport properties in a PEMFC by optimizing the design of MPL ink. Detail experimental results will be presented at the conference.

References

[1] H. K. Atiyeh, K. Karan, B. Peppley, A. Phoenix, E. Halliop, and J. Pharoah, “Experimental investigation of the role of a microporous layer on the water transport and performance of a PEM fuel cell,” J. Power Sources, vol. 170, no. 1, pp. 111–121, 2007.
[2] J. H. Nam, K. J. Lee, G. S. Hwang, C. J. Kim, and M. Kaviany, “Microporous layer for water morphology control in PEMFC,” Int. J. Heat Mass Transf., vol. 52, no. 11–12, pp. 2779–2791, 2009.
[3] Z. Qi and A. Kaufman, “Improvement of water management by a microporous sublayer for PEM fuel cells,” J. Power Sources, vol. 109, no. 1, pp. 38–46, 2002.
(Invited) From Precursors to Devices: Using Neutron Scattering to Study Synthesis, Processing, and Material Properties
Authors: Sacci Robert L 
Published: February 2020

In this talk, I will report the use of neutron scattering to probe the synthesis of the lithium ion conductor Li7La2Zr2O14 (LLZO) from different precursors and how phonons affect the ion transport in situ. Only a few solid state systems have been studied systematically in terms of synthesis and processing mechanisms. These types of studies and the facilitating in situ techniques are essential to not only solid-state chemistry but chemistry in general. In relation to energy storage devices, we need materials that allow for increased energy density, power performance, lifetime and safety. Solid state batteries are a promising solution in improving a number of these areas over traditional Li-ion batteries; however, efficient synthesis and processing of materials for solid-state batteries are needed to overcome cost concerns [cite]. As such, we need to understand how these materials are formed in order to improve functionality, robustness, and lower processing cost.
Neutron scattering has advantages over x-ray scattering and optical spectroscopies; for example, neutrons have high penetration power and are sensitive to isotope labeling. The combination of these two facts allow for precursor-to-property investigations. In the first part we will raise the question does the initial state of precursors affect reaction mechanism? Specifically, we probe the difference in the reaction the mechanism of LLZO synthesis from a dehydration of eutectic mixture and freeze drying of aerosolized solution. We will show that the reaction rate and chemical structure is strongly affected by how the precursors were mixed.
Moving from synthesis to material property I will report on the simultaneous use of impedance spectroscopy and inelastic neutron scattering (INS) to probe ion transport/phonon correlations. INS is analogous to infrared and raman spectroscopy in that it probes molecular vibrations and phonons of materials. However, unlike optical spectroscopies, INS has no selection rules, as they interact directly with nuclei and not the electrons in the system. Appling an AC signal whose frequency is in resonance with ion transport shows structural or chemical effects in the INS spectra. These effects seem to correlate with phonons that are are associated with Li ion transport.
The Impact of Coal Mineral Matter (alumina and silica) on Carbon Electrooxidation in the Direct Carbon Fuel Cell
Authors: Moradmand Simin , Allen Jessica A , Donne Scott W 
Published: February 2020

Direct carbon fuel cell (DCFC) as an electrochemical device has been considered to generate electricity from coal with higher efficiency and lower air pollution issues than the traditional coal-fired power plant. The coal char as one the main carbonaceous fuel source has been successfully used in DCFC and showed good performance in different cell configurations.
Despite the advantages of DCFC, the development of this technology still has some challenges which must be addressed before becoming commercially viable. The carbon part of coal char consumed during electrochemical reaction to produce the electricity while the mineral part of it will stay unchanged after the reaction and accumulate in the system by the time. Some of these mineral matters act as the inhibitors for carbon electrooxidation and some of them play as the catalysis.
In this study, the impact of two main mineral matters exist in the coal char, alumina and silica, have been investigated in carbon electrooxidation in the half-cell setup. These mineral mixed with ternary (Li2CO3 , Na2CO3 ,
K2CO3 ) with the different mass ratio to obtain the optimum condition for carbon electrooxidation. In addition, the influence of silica and alumina on the melting temperature of electrolyte have been studied with TGA/DTA method to observe any changes in melting temperature or activation energy of melting.
New Insights on the Surface and Stress Behavior of Manganese-Oxide As Oxygen Reduction Reaction Catalyst in Alkaline Electrolyte
Authors: Keisar Or , Ein-Eli Yair , Cohen Yair 
Published: February 2020

The electro-catalysts for oxygen reduction reaction (ORR) on air-cathode have a decisive impact on metal-air batteries and fuel cells. Much effort has been invested in finding a cost effective electro-catalyst, enabling a decrease in the ORR over-potential and enhancing the power source device discharge performance.[1-2]

Manganese-oxides (MnOx) are particularly interesting as non-precious ORR electro-catalysts candidates due to their rich oxidation states, chemical compositions and their variety of crystal structures[1-3]. In order to broaden our understanding on the catalytic mechanism of Manganese-Oxide and its surface chemistry during ORR, we performed unique in-situ electrochemical surface stress (ESS) measurements[4].
The in-situ ESS response was measured on an Au/MnOx electrode in both Ar and O2 saturated environments. A complex stress response was measured during the electrochemical scan caused by various crystal structure transitions[5]. The presence of oxygen resulted in a less compressive stress response during the ORR; suggesting that part of the activated sites on the surface are reduced and re-oxidized (Mn4+↔Mn3+) during the ORR. These observations evidently support the proposed ORR catalytic mechanism[3,5].
In addition, an overall tensile trend was recorded during multiple cycling, pouring some light on the poor mechanical stability of the MnOx film. This insight has major implications on the applicability of MnOx as a catalyst on practical carbon based electrodes.
References:

R. Mainar, L.C. Colmenares , O. Leonet , F. Alcaide , J.J. Iruin , S. Weinberger , V. Hacker , E. Iruin , I. Urdanpilleta , J.A. Blazquez., Manganese oxide catalysts for secondary zinc air batteries: from electrocatalytic activity to bifunctional air electrode performance, Electrochimica Acta 217 (2016) 80–91.

Li, M. Gong, Y. Liang, J. Feng, J.-E. Kim, H. Wang, G. Hong, B. Zhang, and H. Dai., Advanced zinc-air batteries based on high-performance hybrid electrocatalysts, Nature Commun., 4 , (2013), 1805-1811.

A. Stoerzinger, M. Risch, B. Han and Y. Shao-Horn, Recent insights into manganese oxides in catalyzing oxygen reduction kinetics, ACS Catal., 5, (2015), 6021-6031.

Ha, J.L. Oberst, Z. Zeng, T. T.H. Hoang, Y. Cohen, D.J. Wetzel, R.G. Nuzzo, J. Greeley and A.A. Gewirth, In Situ Surface Stress Measurement and Computational Analysis Examining the Oxygen Reduction Reaction on Pt and Pd., Electrochimica Acta, 260, (2018), 400-406.

Gorlin, B. Lassalle-Kaiser, J. D. Benck, S. Gul, S. M. Webb, V. K. Yachandra, J. Yano and T. F. Jaramillo, In situ X-ray absorption spectroscopy investigation of a bifunctional manganese oxide catalyst with high activity for electrochemical water oxidation and oxygen reduction, J. Am. Chem. Soc., 135, (2013), 8525-8534.
Effects of Native Solid Electrolyte Interphase Layer Formation of Cu Electrode on Lithium Electrodeposition/Dissolution Processes
Authors: Kondo Toshihiro , Uchino Yukina , Smaran Kumar Sai , Ohama Ayano , Niida Asako , Nishihara Kaho 
Published: February 2020

Lithium has been extensively expected as one of the most ideal anode materials of the next generation lithium-based batteries such as a lithium-air battery (LAB), because of its higher theoretical specific capacity (3860 mA h g-1) and its most negative redox potential (-3.04 V vs. SHE). During charging, however, it is well known that the dendrite, which further leads to poor performance and short circuit, forms on the lithium anode surface. In addition, solid electrolyte interphase (SEI), which is generated by decomposition of electrolytes and/or solvents, also accumulates on the anode surface during the anode reaction. An ideal SEI layer is expected to be higher and lower conductive for lithium ion and electron, respectively, and it is flexible and has a relatively uniform flat surface with an appropriate thickness, in order to avoid dendrite formation [1]. Thus, we have been trying to construct the “ideal SEI” on the electrode surface [2].
During the electrochemical reaction, on the other hand, electrochemical quartz crystal microbalance (EQCM) technique gives us information not only of mass change on the electrode surface but also resonance resistance change, which shows surface area change of the electrode [3,4] and/or density and viscosity change at the electrode/electrolyte solution interface [5,6]. Moreover, this technique provides us the viscoelasticity of the formed layers on the electrode by the admittance analysis. Using this technique, we found that the native-SEI, which is prepared by the pre-electrochemical treatment of Cu EQCM electrode, strongly effects on the lithium electrodeposition/dissolution processes.
Acknowledgements: This work was totally supported by the Advanced Low Carbon Technology Research and Development Program (ALCA), specially promoted research for innovative next generation batteries (SPRING) from the Japan Science and Technology (JST).
References:
[1] X.-B. Cheng, R. Zhang, C.-Z. Zhao, F. Wei, J.-G. Zhang, Adv. Sci.3 (2016) 1500213.
[2] K. S. Smaran, S. Shibata, A. Omachi, A. Ohama, E. Tomizawa, J. Phys. Chem. Lett.8 (2017) 5203.
[3] K. Kanamura, S. Shiraishi, Z. Takehara,J. Electrochem. Soc.147 (2000) 2070.
[4] D. Aurbach, M. Moshkovich, Y. Cohen, A. Schechter, Langmuir15 (1999) 2947.
[5] K. Naoi, M. Mori, Y. Naruoka, W. M. Lamanna, R. Atanasoski, J. Electrochem. Soc.146 (1999) 462.
[6] N. Serizawa, S. Seki, K. Takei, H. Miyamoto, K. Yoshida, K. Ueno, N. Tachikawa, K. Dokko, Y. Katayama, M. Watanabe, T. Miura, J. Electrochem. Soc.160 (2013) A1529.