bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel Ni Based Duplex Coatings for Anticorrosion Applications
Authors: Yusuf Moinuddin M , Bahgat Ahmed , Shakoor R A , Kahraman Ramazan , Montemor M. F 
Published: February 2020

Ni-B/Ni-P-CeO2 duplex coatings containing inner Ni-B layer were synthesized through the electrodeposition process. A mild steel sheet was used as substrate material to deposit the coatings. The structural, surface and electrochemical properties of the duplex coatings in their as synthesized condition were compared with Ni-P, Ni-B and binary Ni-B/Ni-P duplex coatings to demonstrate the improved performance of Ni-B/Ni-P-CeO2 duplex coatings. The structural analysis (XRD) indicates that the developed coatings exhibit amorphous behavior. The SEM and AFM studies indicate that Ni-B/Ni-P-CeO2 duplex coatings have less surface defects and more defined nodular structure compared to Ni-P, Ni-B and Ni-B/Ni-P duplex coatings. However, these coatings show an increase in surface roughness which may be attributed to the incorporation of CeO2 ceramic particles used as reinforcement. The Ni-B/Ni-P-CeO2 duplex coatings present superior anticorrosion properties compared to Ni-B and duplex Ni-B/Ni-P coatings. The improved electrochemical performance of novel Ni-B/Ni-P-CeO2 duplex coatings can be regarded as the effect of less defective structure produced due to blocking of pores and reduction in the active area of the Ni-B/Ni-P matrix by the presence of CeO2 ceramic particles. Owing to tempting properties, Ni-B/Ni-P-CeO2 duplex coatings may be considered as potential candidate for oil and gas industry.
Kelvin Force Probe Microscopy of Ferroelectric Si:HfO2
Authors: Marinskiy Dmitriy , Polakowski Patrick , Lagowski Jacek , Wilson Marshall , Edelman Piotr , Müller Johannes 
Published: February 2020

Since the demonstration of the ferroelectric properties in hafnium based oxides in 2011 there is large interest to such films for ferroelectric FET, memory, and other applications. Engineering of ferroelectricity in HfO2 relies on doping and annealing. For Si-doped HfO2films, a top metal electrode capping layer is deposited prior to annealing which is shown to cause ferroelectric behavior.
In this paper we present results of non-contact corona-Kelvin characterization of poling phenomena for ferroelectric Si:HfO2 thin films. Measurements were performed on free dielectric surfaces. The method uses corona charging and Kelvin force probe measurements. Corona charging pulses are analogous to voltage biasing, except that no top electrode is needed. Corona charging enables biasing the Si:HfO2to a near coercive field where onset of poling occurs. Mapping of the surface voltage with a small diameter Kelvin force probe allows to quantify poling phenomena, its uniformity and degradation during repetitive switching (Fig. 1).
These results are of importance for fundamental understanding of switching mechanisms of ferroelectric Si:HfO2 films.

Figure 1
(Invited) Improvement of Perovskite Films and the Perovskite/TiO2 Interface
Authors: Zhang Peng , Wang Yafei , Liu Detao , Li Shibin , Chen Zhi David 
Published: February 2020

Perovskite solar cells (PSCs) based on organometallic halide have received wide attention and been developed rapidly in recent years. However, the grain boundaries in perovskite film and defects in the interface in perovskite films dramatically degrade PSCs performance.
Solvent annealing is an efficient method to fabricate high quality perovskite film with less grain boundaries. While most works carried out focused on the solvent annealing of perovskite films, we annealed PbI2 films in DMF, DMSO, acetone, and isopropanol (IPA) atmospheres and studied the effect of different atmospheres. We found that dense PbI2 was formed by annealing in DMF, acetone, and IPA atmospheres, which impeded the full reaction between PbI2 and CH3NH3I. Meanwhile, DMSO solvent annealing process led to porous PbI2 films, which facilitated the complete conversion of PbI2 to perovskite with larger grain sizes. As a result, Solar cells based on DMSO solvent annealing process exhibited the best efficiency of 18.5%, with a fill factor of 76.5%.
We also annealed PbI2 in DMSO and CH3NH3PbI3 in ethanol for fabrication of pinhole-free CH3NH3PbI3 films on ZnO nanorods. Due to the suppression of carrier recombination by large grains, ZnO nanorods based PSCs with best efficiency of 17.3% was obtained.
To suppress the interface defect, Li-doping compact TiO2 was also used as electron transport layer (ETL). Li doping reduced electron trap density and increased the conductivity of the ETL. As a result, the Li-doped compact TiO2 based planar heterojunction PSCs exhibit negligible hysteretic J-V behavior. Comparing with the undoped compact TiO2 based PSCs, the PCE of the Li-doped compact TiO2 film based PSCs is improved from 14.2% to 17.1%.

Figure 1
(Invited) Enabling New Domains of Energy Storage through Atomic Layer Deposition
Authors: Rubloff Gary W 
Published: February 2020

The portfolio of materials accessible by atomic layer deposition (ALD) processes has encompassed all key components of electrochemical energy storage (EES) – cathodes, anodes, solid electrolytes, and interphases. This provides a rich environment in which to advance the science of EES, particularly due to the exceptional thickness and conformality control inherent in underlying ALD mechanisms. Here we highlight three regimes where ALD is most promising to impact battery technology. (1) ALD-based electrode protection layers seem to offer the shortest term technology impact, providing ion permeability while serving as passivation against the varied modes chemical, electrochemical, and mechanical degradation regularly found in batteries, improving cycle life and suppressing dendrite formation. (2) ALD-based solid state batteries offer benefits in structural simplicity and control well beyond that available in commercial devices employing sputtered films. ALD solid electrolytes play a critical role in both protection layers and solid state batteries. (3) 3D solid state batteries exploit high surface areas and thin conformal layers over high aspect ratio topography to achieve higher power-energy performance than planar counterparts. Examples illustrating these opportunities include ALD LiPON protection of metal anodes and conversion electrodes, new pathways to solid electrolyte synthesis, and planar and 3D solid state batteries employing ALD for most or all components.
Supported as part of the Energy Frontier Research Center (EFRC) Nanostructures for Electrical Energy Storage (NEES), funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under award number DESC0001160.
(Invited) Functional Oxides for Energy Efficient Information Technology
Authors: Dubourdieu Catherine 
Published: February 2020

Complex oxides exhibit a wide range of electrical, magnetic, optical, mechanical properties, which may even be coupled. In the past fifteen years, tremendous progresses have been achieved in the growth of complex oxides on oxide substrates, resulting in unit-cell scale control (~0.4 nm for a perovskite). Concurrently, breakthroughs in characterization techniques and modeling have resulted in a better understanding of the effects of composition, size, strain and boundaries conditions on their properties. If complex oxides could be integrated as an add-on to semiconductor technologies in a seamless process, their extraordinary wealth of physical properties could offer new functionalities in devices in order to address societal needs related to health, energy or information & communication technologies.
In this presentation, I will review some aspects on the synthesis, characterization and integration of oxide heterostructures on semiconductors. The scientific and technological challenges for achieving monolithic integration will be presented. Molecular beam epitaxy provides unique advantages to precisely construct, almost atom by atom, the oxide/semiconductor interface to achieve epitaxy. With the case of the ferroelectric BaTiO3 perovskite on Si and SiGe, we will exemplify the various strategies developed to engineer the interface with the semiconductor and to control the oxide crystalline structure and properties.
Regarding SiGe substrates, we will show that a direct growth of BaTiO3 can be achieved on strained Si0.8Ge0.2/Si. The passivation of the starting surface will be discussed. From the X-ray diffraction analysis, the films are found to be oriented with <112> directions perpendicular to the substrate's surface and show two distinct in-plane orientations. An orthorhombic epitaxial silicate is formed at the interface with Si0.8Ge0.2 which gives rise to the 112 epitaxial growth of BaTiO3.The cationic and oxygen compositions of the film and interface will be discussed.
Regarding the growth on Si substrates, we will emphasize the role of size effect and of electrical /mechanical/chemical boundary conditions on the resulting ferroelectric properties. Ferroelectricity down to 4 monolayers of BaTiO3 (1.6 nm) is evidenced with two distinct switchable polarization states.
Finally, we will present current and potential realizations towards complex oxide nanoelectronics with reduced power consumption and towards integrated photonics. The integration of amorphous/nanocrystallites BaTiO3 is a promising approach to reach ferroelectricity in a metal-oxide-semiconductor device. Such composite material exhibits the advantageous properties of an amorphous dielectric of medium relative permittivity with a low leakage current density (˜ 10-7 A/cm2at -1V) while being ferroelectric at room temperature. It is particularly suitable for negative capacitance field-effect devices as well as for memristive devices.
Rate Dependent Multi-Mechanism Discharge of Ag0.50VOPO4·1.8H2o: Insights from in-Situ Energy Dispersive X-Ray Diffraction
Authors: Huie Matthew M. , Bock David C , Bruck Andrea , Yin Jiefu , Takeuchi Kenneth J , Takeuchi Esther S , Marschilok Amy C 
Published: February 2020

Ag0.
50VOPO4·1.8H2O (silver vanadium phosphate, SVOP) demonstrates a counterintuitive higher initial loaded voltage under higher discharge current. Energy dispersive X-ray diffraction (EDXRD) from synchrotron radiation was used to create tomographic profiles of thick cathodes at various depths of discharge for two discharge rates. SVOP displays two reduction mechanisms, reduction of a vanadium center accompanied by lithiation of the structure, or reduction-displacement of a silver cation to form silver metal. In-situ EDXRD provides the opportunity to observe spatially resolved changes to the parent SVOP crystal and formation of Ag0 during reduction. Discharge rate can influence the preferred initial reaction either V5+ reduction or reduction of Ag+ with formation of conductive Ag0. Discharge rate also affects the spatial location of reduction products. This study highlights the importance of mesoscopic analysis and illuminates the roles of electronic and ionic conductivity limitations within a cathode and how they impact the course of reduction processes and loaded voltage.
Interactions of Nanostructured TiO2 with Nonaqueous Electrolytes for Na-Ion Batteries
Authors: Smith Kassiopeia , Parrish Riley , Barnes Pete , Savva Andreas , Karsann Devan , Deng Changjian , Dufek Eric J. , Xiong Hui (Claire) 
Published: February 2020

Current shifts towards renewable energy technologies have increased the drive for high performance and cost effective battery systems. Sodium ion batteries present a promising alternative to the commonly used lithium-ion batteries and offer several benefits such as low cost and high availability. While lithium-ion battery systems have been studied intensively, it has become apparent that the interfacial chemistry differs significantly for sodium ion batteries, even when using the same solvents.
In previous work, we have shown that amorphous TiO2 nanotube electrodes are a suitable anode materials for Na-ion batteries. The optimization of electrolytes is important to develop a system with good solubility, high transport properties, electrochemical and interfacial stability. In this work, we have investigated the electrochemical properties of TiO2 nanotube electrodes - as a model system - in various electrolytes containing different solvent mixtures (cyclic and acyclic carbonates) with NaClO4 and NaPF6 salt. In addition, we have conducted fundamental studies of chemical, thermal, and electrochemical stability of the chosen sodium-based electrolytes with a phosphazene-based additive FM2 as well as the commonly used FEC additive.
Pt-Ru/C Catalyst Performance during Direct Methanol Fuel Cell Operation
Authors: Pereira Drew Joseph , Wilkins Cody H , Shimpalee Sirivatch , Weidner John W. 
Published: February 2020

A methodology for the electroless deposition (ED) of ruthenium (Ru) on a commercial, carbon-supported Platinum (Pt) catalyst has been developed for electrochemical and fuel cell applications [1, 2]. Several different bimetallic catalysts composed of Pt and Ru have been produced using this methodology with promise of having better catalytic activity. Figure 1 shows how the SEA/ED method produces a finer, more evenly dispersed bimetallic distribution with less monometallic clustering [1]. These bimetallic catalysts have shown higher activities compared to both commercially-available Pt-Ru/C catalysts and monometallic Pt or Ru catalysts [3, 4]. This method’s bimetallic catalyst is proven to show better resistance to CO poisoning as well [3, 5, 6]. In application, this Pt-Ru/C catalyst has promise to be an optimal catalyst for use in a Direct Methanol Fuel Cell (DMFC).
The objective for this study is to test the performance of the new Pt-Ru/C catalyst within a DMFC and compare the results to the commercially-available catalyst. This includes synthesis of the SEA/ED, Pt-Ru/C catalyst, characterization of the commercially-available and newly-synthesized catalyst with analysis, and finally, testing of each catalyst within a DMFC testing station and analyzing performance results. The DMFC testing and comparison is important to help show the catalysts’ real-world performance as well as effects of possible CO-poisoning during operation. The newly-synthesized catalyst has an increased electrochemical area as well as a better bi-metallic dispersion, to allow ruthenium to better prevent any platinum from being poisoned, causing the catalyst to perform better and last longer.
1. Diao, W., et al., Preparation and Characterization of Pt–Ru Bimetallic Catalysts Synthesized by Electroless Deposition Methods. ACS Catalysis, 2015. 5(9): p. 5123-5134.
2. Cho, H.-R. and J.R. Regalbuto, The rational synthesis of Pt-Pd bimetallic catalysts by electrostatic adsorption. Catalysis Today, 2015. 246: p. 143-153.
3. Garrick, T.R., et al., The Effect of Bimetallic Surface Composition for Methanol Oxidation. Student Posters (General) - 223rd Ecs Meeting, 2013. 53(29): p. 79-84.
4. Garrick, T.R., et al., The Effect of the Surface Composition of Ru-Pt Bimetallic Catalysts for Methanol Oxidation. Electrochimica Acta, 2016. 195: p. 106-111.
5. Galhenage, R.P., et al., Platinum–ruthenium bimetallic clusters on graphite: a comparison of vapor deposition and electroless deposition methods. Physical Chemistry Chemical Physics, 2015. 17(42): p. 28354-28363.
6. Kabbabi, A., et al., In situ FTIRS study of the electrocatalytic oxidation of carbon monoxide and methanol at platinum–ruthenium bulk alloy electrodes. Journal of Electroanalytical Chemistry, 1998. 444(1): p. 41-53.

Figure 1
(Invited) Elucidating Oxygen Evolution on Model Oxide Electrodes
Authors: Stephens Ifan Erfyl Lester 
Published: February 2020

It is particularly challenging to catalyse oxygen evolution under the acidic conditions of polymer electrolyte membrane (PEM) electrolysers. All compounds, apart from IrO
x
and RuO
x
, are catalytically inactive or unstable. I will present a series of model studies where we aim to elucidate the factors that control oxygen evolution.
Using thin films of RuO2, we showed that continuous mass losses occur in parallel to oxygen evolution, even when the electrochemical response is stable.1 This finding demonstrates that short term electrochemical measurements are an insufficient measure of long term stability. Our experiments on mass-selected Ru and RuOx particles revealed the high sensitivity of the oxygen evolution performance of nanoparticulate catalysts to the exact oxidation treatment.2,3 X-ray absorption measurements, taken in-operando, provide spectroscopic evidence for the potential dependent coverage of the reaction intermediates. Moreover, tests on oriented thin films indicate that the “coordinatively unsaturated” surface site is responsible for the activity of RuO2.4 Our very recent studies suggest that the dissolution rate of RuO2 is also highly dependent on the orientation.
The scarcity of RuOx and IrOx could limit the scalability of PEM electrolysers. An alternative strategy could be utilise non-precious metal oxides to catalyse oxygen evolution in acid. However, most non-precious metal oxides exhibit poor stability. Theoretical calculations predicted that MnO
x
could be stabilised against corrosion by the presence of TiO
x
at its surface, without affecting the catalytic activity. Our experiments on sputter-deposited thin films verify this notion. 5

The catalysts under investigation include model-size selected nanoparticles, commercial high surface area catalysts, sputtered films and oriented thin films. We have probed these surfaces with electrochemical measurements, ultra-high vacuum based surface science methods, electron microscopy, synchrotron-based spectroscopy and density functional theory calculations.

1 Frydendal, R., Paoli, E. A., Knudsen, B. P., Wickman, B., Malacrida, P., Stephens, I. E. L. & Chorkendorff, I.
ChemElectroChem
1, 2075, (2014).
2 Paoli, E. A., Masini, F., Frydendal, R., Deiana, D., Malacrida, P., Hansen, T. W., Chorkendorff, I. & Stephens, I. E. L.
Catal.

Today
262, 57, (2016).
3 Paoli, E. A., Masini, F., Frydendal, R., Deiana, D., Schlaup, C., Malizia, M., Hansen, T. W., Horch, S., Stephens, I. E. L. & Chorkendorff, I.
Chemical Science
6, 190, (2015).
4 Stoerzinger, K. A., Diaz-Morales, O., Kolb, M., Rao, R. R., Frydendal, R., Qiao, L., Wang, X. R., Halck, N. B., Rossmeisl, J., Hansen, H. A., Vegge, T., Stephens, I. E. L., Koper, M. T. M. & Shao-Horn, Y.
ACS Energy Letters
, 876, (2017).
5 Frydendal, R., Paoli, E. A., Chorkendorff, I., Rossmeisl, J. & Stephens, I. E. L.
Adv. Energy Mater.
5, 1500991, (2015).
Stochastic Generation of Sintered Titanium Powder-Based Porous Transport Layers in Polymer Electrolyte Membrane Electrolyzers and Investigation of Structural Properties
Authors: Lee Jason Keonhag , Bazylak Aimy 
Published: February 2020

One of the factors leading to a decrease in the efficiency of polymer electrolyte membrane (PEM) electrolyzers is the blockage of water transport pathways through the porous transport layer (PTL). The oxygen bubbles generated from the electrochemical reaction at the catalyst layer accumulate in the PTL, impeding the transport pathways and reaction sites for the reactant water (1). An improved understanding of oxygen bubble accumulation and water transport behaviour in porous transport layers is essential to reduce mass transport losses in PEM electrolyzers.

This study presents a method to stochastically generate a PTL composed of sintered titanium (Ti) powders and investigate the transport properties using pore network modeling. A microscale X-ray computed tomography (µ-CT) was performed for a sintered Ti powder PTL sample to obtain a 2D density map. The density map contains material content information, providing higher intensity at the positions with higher material content. With the density map as an input, a stochastic model of the PTL was generated by placing Ti powder particles at positions decided by the density map and a probability function until the model reached the target volume (2). Two critical parameters are considered in this model: the seeding parameter, α, and a filling radius, β. The seeding parameter controls the number of Ti powder “seeds” that act as nucleation sites. The second parameter, the filling radius, allows the model to mimic the morphology of the sintered regions. The structural properties of the stochastic model are investigated by comparing the pore size distribution, throat size distribution, and the porosity profile to the µ-CT reconstruction.

Pore network modeling is an alternative to continuum modeling for simulating transport in porous media. Pore network modeling simplifies the solution of differential equations for mass transport by treating the pore space as a network of pores and narrow throats (3). Using pore network modeling as the analysis tool, the in-plane permeabilities of the µ-CT reconstruction and the stochastic model were compared.

The stochastic modeling of PTLs will facilitate the detailed parametric studies of PTL structural property impacts on transport and provide novel insights into mass transport behavior in PEM electrolyzers.
References

H. Ito, T. Maeda, A. Nakano, Y. Hasegawa, N. Yokoi, C. M. Hwang, M. Ishida, A. Kato, and T. Yoshida, International journal of hydrogen energy
35(18), 9550-9560 (2010).

A. Ebrahimi Khabbazi, J. Hinebaugh, A. Bazylak, Science Bulletin, 61(8), 601-611(2016).

A. Putz, J. Hinebaugh, M. Aghighi, H. Day, A. Bazylak, and J. T. Gostick, ECS Transactions, 58(1), 79-86 (2013).
Dendrite-Suppressed Lithium Plating from a Carbonate-Based Liquid Electrolyte
Authors: Park Kyusung , Goodenough John B. 
Published: February 2020

Lithium metal is an ultimate anode material to achieve the highest energy density for a given cathode by providing a higher cell voltage and capacity. However, lithium is not used as the anode in commercial lithium-ion batteries because electrochemical dendrite formation and growth during charge can induce a cell short-circuit and the corresponding safety hazards. Plating of lithium through a bed of solid electrolyte particles is shown to transform dendrite growth into a three-dimensional lithium network formed by wetting the particle surfaces in the presence of a carbonate-based liquid electrolyte. It was also found that not every solid electrolyte could be wet by lithium in our systematic investigation.
Upon wetting by lithium metal, a higher overpotential during Li deposition than that with dendrite growth was observed in galvanostatic charge/discharge tests. The characteristic overpotential increase could be correlated with the morphological changes and a more isotropic growth behavior. The origin of the bonding responsible for wetting of the solid-electrolyte particles by lithium will be discussed.