bluuebunny/crossref_metadata_2025_split huggingface dataset:
A NiO-RuO2 Nanoparticle-Decorated Carbon Powder Cathode for Non-Aqueous Lithium-Oxygen Batteries
Authors: Tan Peng , Shyy Wei , Zhao Tianshou 
Published: February 2020

Non-aqueous lithium-oxygen batteries have been considered as one of the most promising power sources for electric vehicles and portable devices, due to the high theoretical capacity (3.86×103 mAh g-1) and energy density (1.14×104 Wh kg-1) [1]. The electrochemical reactions in the discharge and charge processes involve the formation and decomposition of the solid product Li2O2 in the cathode. Carbon has been regarded as one of the most attractive cathode materials, due to its good conductivity, high specific area, proper pore volume, and low cost. However, it has been shown that both the highly oxidizing environment (O2
-) and Li2O2 can lead to the decomposition of carbon materials to form a thin Li2CO3 film at the carbon interface [2]. Besides, carbon can promote decomposition of the electrolyte to form side products (e.g. lithium carbonate and carboxylates) [3]. These irreversible side products accumulate on the cathode surface, leading to a high overpotential during charge, resulting in a short cycle life.
A new strategy to solve these issues is to promote the decomposition of side products. In this regard, we here developed a NiO-RuO2 nanoparticle-decorated carbon powder cathode. As NiO has been reported to have activity in the oxidation of carbonate and carboxylate species [4], we used NiO nanoparticles to decorate the carbon powder with two features: i) protect the surface defects, alleviating the decomposition of the electrolyte; and ii) promote the oxidation of side products, retaining the activate surfaces. To further lower the charge overpotential, we meanwhile decorated RuO2 nanoparticles on the carbon powder surface. As a result, this NiO-RuO2 nanoparticle-decorated carbon powder cathode can enable a non-aqueous lithium-oxygen battery with a low charge overpotential and long cycle life.
Further analysis and electrochemical characterizations will be presented at the meeting. The lithium-oxygen battery performance employing this type of cathode will also be presented at the meeting.

References

[1] G. Girishkumar, B. McCloskey, A.C. Luntz, S. Swanson, W. Wilcke, Journal of Physical Chemistry Letters. 1 (2010) 2193-2203.
[2] B.D. McCloskey, A. Speidel, R. Scheffler, D.C. Miller, V. Viswanathan, J.S. Hummelshoj, J.K. Norskov, A.C. Luntz, Journal of Physical Chemistry Letters. 3 (2012) 997-1001.
[3] M.M. Ottakam Thotiyl, S.A. Freunberger, Z. Peng, P.G. Bruce, J. Am. Chem. Soc. 135 (2013) 494-500.
[4] M. Hong, H.C. Choi, H.R. Byon, Chemistry of Materials. 27 (2015) 2234-2241.
Engineering Metal Nano-Composite As Anode in High-Performance Li-Ion Batteries
Authors: Niu Junjie 
Published: February 2020

Due to a high theoretical capacity and an excellent Li+/e- conductivity, the worldwide available metals such as Tin and Aluminum anticipates attractive applications in energy storage. Unfortunately the battery performance is limited because of the pulverization and oxidation. In order to prevent these, here we present a metal nano-composite, which is constructed by a pure metal nanoparticle and a “breathing” thin shell with a flexible interspace, using an in situ chemical redox. This new configuration can effectively avoid the loss of pulverized active material while providing a fast pathway for Li+/e- transport. In parallel, the controllable void inside can accommodate the large volume expansion to ensure a sufficient adhesion to the shell, leading to a high cyclability and an excellent rate capability. The current facile, low-cost approach to metal nano-composite will open an avenue in next-generation Li-ion batteries in replacing graphite anode electrode.
The Role of Composite Binder on Mechanics and Performance of Lithium Ion Battery Electrodes
Authors: Grillet Anne M. , Humplik Thomas , Stirrup Emily K. , Barringer David , Mendoza Hector , Roberts Scott A. , Snyder Chelsea Marie , Apblett Christopher A. , Fenton Kyle R , Long Kevin N. 
Published: February 2020

Battery electrodes are complex multiphase composites which must provide efficient bicontinuous networks for transport of electrons (through the particle phase) and positive lithium ions (through the electrolyte filled pores of the electrode). A crucial but often neglected element of battery electrodes is the binder, typically a mixture of polyvinylidene fluoride (PVDF) and carbon black. The binder has two primary roles – to provide mechanical integrity and to improve electrical conduction of the electrodes. Migration of the binder has also been implicated as a potential mechanism of capacity fade in rechargeable lithium ion batteries.
We will present experimental characterization of the polymer binder for battery applications. Mechanical properties of the composite binder will be shown for both dry films and also binder swollen with carbonate electrolytes used in rechargeable lithium batteries. The electrical properties are strongly dependent on the applied stress and more modestly on the strain rate. The evolution of mechanical and electrical properties of the binder after repeated cycling will be shown.
Mesoscale simulations will be presented using experimentally determined three dimensional structures of battery cathodes. Using these realistic microstructures, the role of polymer binder properties on the effective modulus of the electrode will be examined. The complex particle scale geometry results in a heterogeneous stress distribution with the binder between particle contacts experiencing high localized stresses. Implications for battery internal resistance and cycling stability will be discussed.
Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000. SAND2015-10738 A
Electrodeposition and Stacking to Form 3D Hierarchically Porous Structures
Authors: Robinson David B. , Garcia Gail F. , Nishimoto Ryan K. , Bartsch Michael S. , Arrington Christian L. , Buffleben George M. , Jones Christopher G. 
Published: February 2020

Rapid transport between fluid and solid phases can yield high power density in electrochemical energy storage systems, and efficient chemical separations in chromatography. Transport is often slower in the solid phase, and in long, narrow channels of the fluid phase. Careful architecture can lead to significant improvement of overall transport rates. A known architectural theme that can achieve this is hierarchical porosity, where there are a few long, wide channels connecting to many shorter, narrower channels that provide greater access to the solid phase.
We have fabricated and tested hierarchically porous metal hydride electrodes and chromatography columns with overall dimensions in the millimeter range. The fluid channels are tens or hundreds of micrometers wide. The solid layers are tens of micrometers thick, and penetrated by pores that are about 10 nanometers wide. We achieve this through electrodeposition of thick layers of block copolymer-templated nanoporous palladium onto a fine wire mesh or photoresist-patterned wafer. Pieces of these materials are then stacked and fixed in place to form a defined geometry that is macroscopic in three dimensions. Palladium forms a hydride under mild chemical or electrochemical conditions. We have measured hydrogen transport rates into or out of these structures electrochemically and by mass spectrometry. Transport rates are significantly faster than for cases where one or both scales of porosity are absent. We expect that similar improvements could be demonstrated for other multiphase chemical systems, such as electrodes that store lithium ions, or organic solutes for chemical separations.
Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000. SAND2015-10657A
Investigation on Process Parameters on the Adhesion of Electroless Ni-P Film on Silane Compound Modified Si Wafer
Authors: Hsu Chin Wei , Wang Wei-Yan , Wei Tzu Chien 
Published: February 2020

We previously reported a novel polyvinyl alcohol-capped palladium colloids (PVA-Pd) as the catalyst for the electroless plating of nickel-phosphorous (ELP-Ni-P) film on 3-2-(2-aminoethylamino) ethylamino propyl trimethoxysilane (ETAS)-modified Si surface [1]. It was found the interaction between PVA-Pd and amino-moiety on ETAS is the root cause of the superior adhesion of ELP-Ni-P film without the need of post annealing. The adhesion of ELP-Ni-P film catalyzed by PVA-Pd on ETAS-modified Si surface is significantly improved from 4.63 MPa to 10.83MPa when compared with it made via traditional Sn/Pd process.
In this study, the effect of process parameters in this method including annealing temperature, annealing time, ETAS dipping time, PVA-Pd concentration and PVA-Pd dipping time are systematically investigated by means of design of experiments (DOE). From the analysis of variance (ANOVA) table, it is found the annealing temperature, annealing time and ETAS-dipping time have main effects on the adhesion of ELP-Ni-P film. Surprisingly, SEM cross-sectional image of the ELP-Ni-P film made by this method reveals that imperfect self-assembly monolayer (SAM) formation of ETAS aids the formation of nickel-silicide intermetallic (IMC) layer, rendering an even better adhesion before annealing. On the contrary, the adhesion of ELP-Ni-P film deposited on perfect ETAS monolayer becomes worse after post annealing. We speculate that silane-compound may play as a barrier layer for the IMC formation, which may jeopardize the original function of Ni-P film as the barrier layer for the subsequent copper layer in semiconductor industry.
Reference:
[1] T.-C. Wei, T.-C. Pan, C.-M. Chen, K.-C. Lai, and C.-H. Wu, "Annealing-free adhesive electroless deposition of a nickel/phosphorous layer on a silane-compound-modified Si wafer," Electrochemistry Communications, vol. 54, pp. 6-9, 2015.

Figure 1
Electrochemical Fluorination of Uranium to UF6
Authors: Martinez-Rodriguez Michael Joe , Olson Luke Christopher , Gray Joshua R. , Garcia-Diaz Brenda Lee 
Published: February 2020

The development of efficient and environmentally benign methods to reprocess used nuclear fuel will be enabling technologies for the nuclear renaissance. The primary large scale method for processing used nuclear fuel is aqueous and generates large volumes of high level radioactive waste. The use of electrochemical and fluorination methods for reprocessing used nuclear fuel have been proposed and researched by various groups, but combinations of electrochemical and fluorination methods have not been investigated. Fluorinating agents are extremely potent oxidizers and may electrochemically fluorinate metallic used nuclear fuel with no input of electricity. A galvano-fluorination process has been developed at Savannah River National Laboratory. This electrochemical non-aqueous process enables efficient gas phase uranium recovery while allowing for control of the reaction. Thermodynamic modeling of the electrochemical fluorination process has shown UF6 to be the first gaseous fission product produced during fluorination. Further thermodynamic modeling was used to determine the feasibility of oxide reduction required for oxide fuel before electrochemical fluorination and for experiments. A chemical reactor system for electrochemical fluorination of U with NF3 in a fluoride molten salt was constructed along with vessels for product collection and analysis. This work has proven that an electrochemical reaction happens between U and NF3 which confirms the feasibility of electrochemical fluorination and the development of a processing scheme.
Nickel Electrodeposits As a Model Material to Study Abrasive Waterjet Machining
Authors: Mieszala Maxime , Lozano Torrubia Pablo , Mischler Stefano , Axinte Dragos A. , Michler Johann , Philippe Laetitia 
Published: February 2020

Understanding the erosion mechanism during abrasive waterjet machining is essential to manufacture parts with the desired dimensions, surface finish and mechanical properties. Numerous models1–3exist to predict the effect of the process parameters on the profile of the waterjet footprint. In these models the material properties are either not explicitly considered or taken as homogeneous. In addition, the effect of the original microstructure as well as the microstructural changes during abrasive waterjet machining are usually ignored. Therefore there is a need for a model material with tunable grain size in order to gain better insights into the abrasive wear mechanisms of metals.
Electrodeposition of nickel allows to vary the grain structure and thereby the mechanical properties in a fast, reproducible and inexpensive way. Varying the grain size without changing the composition from nanocrystalline to microcrystalline is highly desirable to perform systematic study. In this poster Ni electrodeposition is used as a tool to study erosion mechanisms during abrasive waterjet milling. By milling trenches in nickel samples with different grain sizes, it was observed that the microstructure has little effect on the erosion rate. Microstructural and mechanical characterization revealed surface nanocrystallization in the microcrystalline nickel specimens due to severe plastic deformation. The surface being altered, the mechanical properties are changed and the erosion rate reduced.
This study shows the potential for using metal electrodeposition to produce model materials to study engineering issues. The range of microstructure offered by electrodeposition enabled us to screen the effect of the microstructure during abrasive waterjet machining. Similar approach could be extended to other machining and finishing processes.
References

1 J. Billingham, C.B. Miron, D. A. Axinte, and M.C. Kong, Int. J. Mach. Tools Manuf. 68, 30 (2013).

2 S. Anwar, D. A. Axinte, and A. A. Becker, Proc. Inst. Mech. Eng. Part J J. Eng. Tribol. 225, 821 (2011).

3 P. Lozano Torrubia, D. A. Axinte, and J. Billingham, Int. J. Mach. Tools Manuf. 95, 39 (2015).
(Invited) Heterogeneous Integration of III-V Semiconductors on Silicon for Electronics
Authors: Lee Rinus 
Published: February 2020

Silicon has been the material of choice to fabricate integrated circuit chips, which are now ubiquitously used in almost all electronic products. However, today’s market demands electronic chips that are more power efficient and diverse in functionalities. To meet these demands, one potential solution is to use III-V semiconductors (including GaN). The ability to tailor the electronic and optical properties of III-V semiconductors seamlessly will allow for lower power and greater functionality in future electronics. However, it is critical that III-V semiconductors are heterogeneously integrated onto silicon to enable the technology to be economically viable.
In this invited talk, we highlight the opportunities and review the most recent progress in heterogeneous integration of III-V semiconductors onto silicon. We will also address the most critical issues that remain to be overcome before III-V semiconductors is adopted for high volume manufacturing in silicon environments. This includes gate dielectric and metal contact interfaces as well as cross-contamination and safety issues of III-V processing in state-of-the-art foundries.
Electrochemical Characterization of Surface States at the GaN/Electrolyte Interface
Authors: Winnerl Andrea , Garrido Jose A. , Stutzmann Martin 
Published: February 2020

In recent years, III-nitride materials – traditionally used in light-emitting diodes, high power and high temperature electronic devices and short-wavelength photodetectors - have attracted considerable interest in photo-electrochemistry and photocatalysis due to the very favorable energy position of its band edges with respect to many redox levels in liquid electrolytes.
Understanding the mechanisms governing charge transfer across the semiconductor/electrolyte interface is important for a quantitative analysis of cyclic voltammetry and impedance spectroscopy. In previous work [1], by combining contact potential difference and photocurrent measurements, we could show that localized surface defect states play a crucial role in the kinetics of photo-generated charges. As a next step, the influence of these electrically active states located in the semiconductor bandgap on the charge transfer to the electrolyte is investigated.
Here, we present a systematic electrochemical study of MOCVD grown n-type GaN in aqueous electrolytes. Cyclic voltammetry and impedance spectroscopy measurements are performed over a wide range of potentials and frequencies to determine the energy positions of GaN charge transfer states and to investigate the electron transfer kinetics between GaN and redox molecules. Furthermore, the surface states are changed by applying different surface treatments and the influence of these on the details of charge transfer is investigated.
[1] A. Winnerl, R. N. Pereira, and M. Stutzmann, Phys. Rev. B 91, 075316 (2015)
TiO2 Compact Layer-Free TiO2 Nanotubes Films Prepared By Anodizing of Ti Grade 2 Immersed in Aqueous Electrolyte
Authors: Ortega-Díaz David , Godinez Mora-Tovar Luis Arturo , Sepúlveda Selene , Manríquez Juan 
Published: February 2020

TiO2 nanotubes (TiO2-NTs) films have been traditionally prepared by electrochemical anodizing of highly pure Ti foils (Ti>99.999%) in aqueous or organic electrolytes. In this sense, since the oxygen content in pure Ti foils could be considered as traces, all the oxygen employed to promoting the growth of TiO2-NTs on this Ti substrates, must be transported from the electrolyte. Therefore, organic solvents such as polyalcohols have been preferred for preparing the electrolytes utilized during Ti anodizing. In this investigation we proposed that industrial grade Ti foils having intercalated oxygen in their crystallographic networks, can be utilized for promoting the formation of TiO2-NTs films in aqueous medium and in the absence of polyol type solvents. Our results confirmed that Ti grade 2 foils were successfully anodized by applying 20V in a two-electrode cell containing a 0.1M NaF + 0.5M H3PO4 aqueous solution an a Pt foil as cathode. Anodizing times were varied at 2, 3 and 4h. The as-prepared TiO2-TNTs films were characterized by scanning electron microscopy (SEM), UV-Vis diffuse reflectance spectroscopy, dispersive Raman spectroscopy (DRS) and X-ray diffraction (XRD).
Before any thermal treatment, SEM images were obtained from the anodized Ti substrates, thus revealing the formation of pristine TiO2-TNTs having averages of 800nm-length, 115nm-internal diameter, and 24nm-wall thickness. Furthermore, the same SEM images revealed the presence of a TiO2 compact layer on the top of all TiO2-TNTs films, whose thicknesses increased as function of anodizing time. In order to remove this compact layer, an ultrasonic field of 42 kHz was applied for 20, 40 and 60s to all the anodized Ti foils. A complete removal of the compact layer was achieved only for the case of the TiO2-TNTs films growth after 3h of Ti anodizing. Finally, a reproducible crystallographic composition of anatase and rutile, were obtained after the thermal treatment of the TiO2-NTs films in good agreement with the literature. Finally, TiO2-TNTs films obtained after 3h of Ti anodizing and 40s of ultrasonic treatment (i.e. TiO2 compact layer-free TiO2-TNTs) were tested as photoanodes of porphyrin-sensitized solar cells having an open-circuit potential of 0.40V, and fill factor of 0.43 under polychromatic illumination. At first sight, these results suggest a promising application of these electrodes into the field of the solar energy conversion devices.
Role of Defects in Enhancing the Electrochemical Properties of Transition Metal Oxide
Authors: Chakrapani Vidhya , Wang Qi 
Published: February 2020

Transition metal oxides are an important class of materials that are valued for their catalytic, ferroelectric, superconducting, and optical properties, and hence they find uses in diverse applications such as heterogeneous catalysts, sensors, solar cells, and high temperature superconductors. Such rich properties of metal oxide are partly enabled by their complex surface chemistry and the presence of lattice vacancies that significantly perturb the electronic structure of the material. Hence, an in-depth understanding of the origin and nature of these defect states is important for further expanding the scope of oxide-based systems for various applications. The focus of this presentation is on elucidating the nature of interaction of various chemicals with defects in metal oxide. The chemical-structure-property correlations developed in this work can enable rational engineering of a new type of nanoscale, low temperature catalysts having tailored functionality and selectivity that can significantly reduce the energy cost and carbon footprint of many important chemical reactions.
(invited) 2-Dimensional Layered Materials for Si Technology
Authors: Shin Hyeon-Jin 
Published: February 2020

Two dimensional (2D) layered materials are crystalline materials with layered structures, including Graphene, h-BN, and Transition Metal Di-chalcogenides (TMD’s). Each of their layers is consisting of one or a few atomic layers and they form van der Waals interactions with neighboring layers. Recently, they have been studied intensively due to their extraordinary properties, such as, flexibility and transparency. In addition, they have exceptional electronic, optoelectronic, chemical and mechanical properties. For example, Graphene has high electron mobility, chemical inertness, and thermal conductivity, while TMD has high photo responsivity. Based on their properties, many potential applications were proposed and demonstrated.
We have been investigated 2D layered materials for Si technology, but not for the active materials. We have focused 2D layered materials as interface materials due to the chemical inertness and their atomically thin nature. Especially, Graphene has been suggested as a promising material for future interconnects because of its unique electrical and chemical properties. For instance, they are good candidates for diffusion barrier.[1]
Also, they are good candidates for interface materials between metal and Si to reduce the schottky barrier heights and contact resistance in source and drain, which is one of the most critical issues for scaling down.[2]
In this talk, we will cover and discuss the possibility of Graphene and other 2D layered materials for interconnects and contact resistance reducer in Si technology. In addition, we will also cover other potential applications based on 2D layered materials’ unique properties, such as, chemical inertness and atomic thick nature.
[1] L.Li et al., “Verticle and lateral copper transport through graphene layer”, ACS Nano, 9(8), pp. 8361-8367 (2015)
[2] K.-E. Byun et al., “Graphene for true ohmic contact at metal-semiconductor junctions”, Nano Letters, 13 (9), pp. 4001-4005 (2013)