bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Process Development and Quality Control for Manufacturing of Lithium-Ion-Batteries
Authors: Wohlfahrt-Mehrens Margret , Braunwarth Wolfgang , Kremer Lea Sophie , Scurtu Rares , Memm Michaela , Hoffmann Alice , Roessler Stefan 
Published: February 2020

The development of efficient and sustainable low cost manufacturing techniques for the next generation lithium-ion cells with improved energy density is a key technology for industrial success. There is a strong need for further development of energy-efficient, resource and time saving electrode and cell manufacturing processes, which includes the identification of bottleneck factors along the whole production chain and the replacement of environmentally harmful intermediate steps (e.g. replacement of NMP for the cathode processing).
One promising approach to increase both energy density of the cell and process efficiency is the reduction of passive materials in the cell by increasing the mass loading of active material on the electrodes. These thicker electrodes, however, suffer from some drawbacks like lower rate capability, lower mechanical flexibility and reduced adhesion to the current collector. In addition, the mixing and coating process parameters have to be adapted to avoid inhomogeneous binder distribution and mechanical disintegration of particles. The electrochemical and mechanical properties of the electrodes are strongly dependent on the 3D microstructure of the electrode (distribution of carbon black, porosity, distribution of the binder network). Both the mixing strategy during slurry preparation as well as the drying conditions during coating have a strong influence on the mechanical and electrochemical properties of the electrodes, which will be discussed in detail in the presentation. Another approach to optimize electrodes with high areal capacity is the preparation of 3D structured electrodes (e.g. gradient electrodes). We studied the addition of various pore forming additives and the preparation of multilayer electrodes via coating with a dual slot die system.
On the anode side silicon based materials are quite attractive due to high specific capacity and energy. However, practical use of silicon is still limited to low amounts of silicon < 5wt% in commercial cells. Anodes with higher silicon content suffer from low cycling life due to high volume change and electrode swelling. A promising approach to improve the cycling life of silicon based electrodes is the use of alternative 3D structured current collectors in combination with adapted binder systems.
In general, the cell manufacturing of Li-ion batteries requires precision and accuracy and includes a complex process chain with numerous process parameters. Optimized parameters for critical manufacturing steps during cell assembly as drying, slitting, electrolyte filling and formation will be presented and discussed in more detail.
Degradation Mitigation of Infiltrated Solid Oxide Fuel Cell Cathodes Via Atomic Layer Deposited Zirconia Overcoats
Authors: Zhang Yubo , Wen Yeting , Huang Kevin , Nicholas Jason D. 
Published: February 2020

To reduce Solid Oxide Fuel Cell (SOFC) cathode operating temperatures, solution infiltration has been used to fabricate Nano-Composite Cathodes (NCCs) comprised of nano-sized mixed ionic electronic conducting oxygen exchange catalysts on sintered, micro-porous, ion-conducting scaffolds.1,2 In these cathodes, degradation due to nano-particle coarsening and/or Sr segregation are a major concern.3 Recent studies have suggested that conformal zirconia overcoats several nm thick produced via Atomic Laser Deposition (ALD) can improve the long-term stability of SOFC cathodes. 4

Since, the low ~200oC ALD deposition temperatures do not coarsen the nanoparticle networks in infiltrated cathodes,5 here ZrO2 ALD overcoats of various thickness were deposited onto high=performance 12 vol% La0.6Sr0.4Co0.8Fe0.2O3-x (LSCF) - Gd0.2Ce0.8O2 (GDC) NCCs. Symmetrical cathodes were produced on both sides of dense, ~500 micron thick (Y2O3)0.08(ZrO2)0.92 electrolytes using previously described procedures.1 Then, porous La0.6Sr0.4MnO3 and gold grids were printed on both sides as current collecting layers, and 400oC-700oC Electrochemical Impedance Spectroscopy (EIS) measurements were performed with a push-contact setup to determine the NCC polarization resistance (Rp) from the EIS Nyquist plot x-intercepts. Transmission Electron Microscopy (TEM) and X-ray Photoelectron Spectroscopy (XPS) were also conducted on NCCs as function of overcoat thickness and degradation time at 650oC.
Figure 1 shows that ZrO2 ALD overcoats 1-10 nm in thickness did not significantly alter the 400-700oC LSCF-GDC NCC Rp. However, as shown in the 1000-hour, 650oC, open circuit Rp degradation tests of Figure 2, increased zirconia overcoat thickness resulted in increased performance stability (at least up to 5 nm of ZrO2). Specifically, the degradation dropped from ~31.6 %/khrs for uncoated LSCF-GDC NCCs, to ~28 %/khrs, ~18 %/khrs, and ~11.7 %/khrs with 1, 2, and 5 nm of ZrO2 overcoat, respectively. TEM analysis showed that the ZrO2 overcoat maintained a constant, conformal, target thickness after 1000 hours at 650oC. XPS analyses on 1000-hour, 650oC aged cells showed that zirconia overcoats decreased the Sr/(La+Sr+Co+Fe) ratio at the surface, providing a possible explanation for the reduced degradation rates of LSCF-GDC NCCs containing ZrO2 ALD overcoats.

Figure 1
Epitaxial Cobaltite Catalysts for Oxygen Evolution Reaction
Authors: Gunkel Felix , Weber Moritz L. , Bäumer Christoph , Dittmann Regina , Waser Rainer 
Published: February 2020

Epitaxy of complex perovskite oxides has arrived at atomic scale precision. This opens new chances and opportunities to the field of electrolysis and water splitting, where perovskite oxides show
promising catalytic activity for the oxygen evolution reaction (OER). While representing ideal model systems for improving our scientific understanding of atomistic processes and scaling relations during OER, epitaxial heterostructures furthermore give access to atomic band engineering strategies and allow the generation of hybrid materials, which may combine beneficial properties of neighboring materials on the nanoscale. These strategies render novel opportunities to enhance chemical stability and to tune overpotentials of OER-active perovskite materials, not accessible in the bulk. Epitaxial catalysts can therefore play an important role in achieving new breakthroughs and guide lines in the field. Here, we discuss synthesis, electronic transport and electrochemical performance of atomically engineered cobaltite thin films. The epitaxial character of the OER catalysts allows to probe parameters such as electronic transport, evolution of crystal structure, over-potential and lifetime, in well-defined sample geometries and in absence of chemical admixture of binders or current collecting materials. As we reveal, single-crystalline epitaxial catalysts can show perfomance well-comparable to powder catalysts whilst revealing (100) crystallographic facets highly favored for oxygen evolution.
References
Weber & Gunkel, Epitaxial catalysts for oxygen evolution reaction: model systems and beyond, JPhys. Energy just accepted manuscript (2019)
Weber et al., Electrolysis of Water at Atmoically tailored Epitaxial Cobaltite Surfaces, Chemistry of Materials, 31(7), 2337 - 2346 (2019)
Gunkel et al., Ordering and phase control in epitaxial (Pr,Ba)CoO3-δ catalysts for oxygen evolution reaction, ACS Catalysis 8, 7029 (2017)
(Invited) Self-Forming High Energy Density Solid State Rechargeable Battery
Authors: Takeuchi Esther S , Marschilok Amy C. , Takeuchi Kenneth J 
Published: February 2020

Solid state batteries are receiving attention due to the possibility of the incorporation of the high energy density of lithium metal coupled with increased safety due to the elimination of flammable organic electrolytes. The lithium/iodine (Li/I2) solid electrolyte battery system has been used successfully for decades as a primary battery to power implantable cardiac pacemakers and has demonstrated an exceptional record of predictability and reliability with high energy density (1536 Wh/L, 560 Wh/kg).
This presentation describes the demonstration of a lithium/iodine rechargeable battery based on the use of LiI rich lithium iodide-(3-hydroxyproprionitrile)2 solid state electrolyte. The battery is first assembled fully discharged using only the solid state electrolyte. The LiI is transformed into the active material where, on charge, lithium metal forms at the negative side of the battery and iodine forms at the positive side. To our knowledge, this is the first demonstration of a rechargeable self-forming solid state lithium battery with electrolyte including LiI(HPN)2. Results on cell formation, cycling, Coulombic efficiency as well as electrochemical impedance spectroscopy will be presented. The results show promise for this conceptual approach for achieving high energy density solid state rechargeable batteries.
Selective Silicon Oxide Overlayers for Solar Hydrogen Production By Seawater Electrolysis
Authors: Bhardwaj Amar A. , Esposito Daniel V. , Yip Ngai Yin 
Published: February 2020

In PV-electrolysis, solar energy can be used to electrolyze water and produce energy-rich hydrogen (H2), a robust energy storage medium. This hydrogen can be fed into a fuel cell for dispatchable electricity to mitigate the daily intermittency of solar photovoltaic generation, or stored and transported over longer timescales. When used as a precursor for traditional fuels, H2 can bring solar energy to difficult-to-electrify sectors such as transportation.
However, solar hydrogen production consumes water, and many of the world’s most sun-drenched regions, such as arid coastal areas, have a scarcity of freshwater and an abundance of seawater. It would be preferable to perform PV-electrolysis with seawater instead of freshwater, but oxidation of the chloride ions from seawater causes the undesired chlorine evolution reaction (CER). This reaction competes directly with the desired oxygen evolution reaction (OER) at the water-splitting anode. CER possesses a strong kinetic advantage over OER, largely because CER involves the transfer of only 2 electrons, while OER is a 4-electron reaction. As such, CER can outcompete OER in saline electrolyte, greatly reducing the faradaic efficiency of the electrolyzer and producing toxic Cl2 gas that is difficult to dispose of.
This research aims to develop an OER-selective catalyst for seawater electrolysis by encapsulation with overlayers of silicon oxide (SiOx)—an amorphous film 2-20 nm thick that is fully stable in the acidic anodic environment. These overlayers were fabricated on planar thin-film platinum electrocatalysts by spin-coating an overlayer of PDMS precursor and converting the PDMS to SiOx in a UV-ozone treatment. The coated electrocatalysts were tested through electrochemical characterization in a three-electrode cell in an acidic aqueous electrolyte with the salinity of seawater. Through electrochemical tests including linear sweep voltammetry, we have shown SiOx-encapsulated Pt electrocatalysts to achieve greatly reduced CER activity compared to bare Pt, leading to faradaic efficiencies of up to 98%, compared to 2.7% for bare Pt. We see that SiOx selectively rejects transport of Cl- through to the buried catalyst while only slightly reducing maximum OER activity. In addition, SiOx has maintained its OER-selectivity throughout long-term operation in chronoamperometry tests. This research makes possible offshore ‘solar fuels rigs’ that use solar electricity to electrolyze seawater. With a SiOx-coated anode catalyst, the electrolyzer could suppress the competing chlorine evolution reaction and produce sustainable hydrogen at high faradaic efficiency.
(Invited) The FC-PAD Consortium: Advancing Fuel Cell Performance and Durability
Authors: Kleen Gregory , Papageorgopoulos Dimitrios C , Weber Adam Z. , Borup Rod L. 
Published: February 2020

The Fuel Cell Performance and Durability (FC-PAD) consortium was formed to advance performance and durability of polymer-electrolyte fuel cells (PEFCs) at a pre-competitive level in order to further enable their commercialization. This consortium coordinates national laboratory activities related to fuel-cell performance and durability, provides technical expertise, and harmonizes activities with industrial developers. The consortium serves as a resource that amplifies DOE EERE’s impact by leveraging the core capabilities of several labs in conducting low technology-readiness-level research. Consortium members include Argonne National Laboratory, Lawrence Berkeley National Laboratory, Los Alamos National Laboratory, the National Renewable Energy Laboratory, and Oak Ridge National Laboratory.
This consortium incorporates national laboratory investigators with proven experience (developed in prior projects) related to durability, transport, and performance, and combines them into one highly coordinated effort. The consortium is divided into six thrusts: three thrust areas related to components ((1) Electrocatalysts and Supports, (2) Electrode Layers, (3) Ionomers, Gas Diffusion Layers, Bipolar Plates, Interfaces), and three cross-cutting thrust areas ((4) Modeling and Validation, (5) Operando Evaluation: Benchmarking, ASTs, and Contaminants and (6) Component Characterization and Diagnostics.) In addition, four external-lab FC-PAD projects are led by 3M Company, General Motors, United Technologies Research Center, and Vanderbilt University. The core national lab team supports those four projects utilizing national lab capabilities.
The major challenge addressed by this consortium is to develop the knowledge base, design rules, and understanding of underlying phenomena in order to mitigate durability concerns and optimize performance through understanding the science of integration, while simultaneously reducing cost. Current research focuses on achieving high performance and durability in low Pt-loaded PEFCs. FC-PAD has conducted significant analysis of MEA electrode structures, analyzed the structures to understand the performance and durability losses, comprehensively defined the current commercial material baseline materials, and used this information to developed new electrode architectures that are designed to minimize existing electrode layer losses. In this talk, in addition to discussion of the consortium itself, recent results will be highlighted including analysis of electrode layers from inks to structure to conditioning to performance.
Acknowledgments
We want to acknowledge all of the FC-PAD researchers, particularly the Research Thrust Coordinators: Deborah Myers (ANL), K.C. Neyerlin (NREL), Ahmet Kusoglu (LBNL), Rajesh Ahluwalia (ANL), Rangachary Mukundan (LANL), Karren More (ORNL). This work is funded through the DOE FC-PAD Consortium with thanks to DOE EERE FCTO.
Measuring Important Properties of EuD4tea: A Material Solution looking for a Problem
Authors: Miller John , Hollerman William A 
Published: February 2020

Triboluminescence (TL) is the light emitted from a material when it undergoes fracture. While this unique phenomenon has been known for over 400 years, no theory has yet to predict whether a material will emit TL. However, this has not stopped scientists from coming up with many unique applications. One such application is the use as the active element for impact and damage sensors. Around the turn of the 21stcentury, researchers used TL to patent a sensor capable of discerning the locations of an impact. Their simple design involved coating a structure with a triboluminescent material or creating a composite triboluminescent object. A sensor would then be embedded within the structure or mounted on its surface. Impacts to the structure would produce light, which would be recorded and analyzed to determine the location. In addition, researchers proposed that several different triboluminescent materials could be used and arranged at various locations. The advantage is that when an impact takes place, its location could be determined by the wavelength emitted. For example, by placing two different triboluminescent materials at known distances from the detector, it is possible to determine the approximate location of the impact by measuring the emitted wavelength.
Material property measurements such as triboluminescent yield and the prompt fluorescence decay time are important considerations for any luminescent material. TL emission has to be sufficiently bright, so that the light signal reaching from the point of fracture to the detector, through a fiber optics cable, is strong enough to be detected. The majority of the known triboluminescent materials do not emit light with sufficient intensity to allow detection with compact and inexpensive detectors. A few materials, such as Europium tetrakis dibenzoylmethide triethylammonium (EuD4TEA), is bright enough to be seen in daylight and has more than twice the triboluminescent emission yield of zinc sulfide doped with manganese (ZnS:Mn) when subjected to low energy impacts. Research has also shown that adding specific dopants to EuD4TEAcan increase the triboluminescent emission yield by more than a factor of five over ZnS:Mn, which is often used as a basis for comparison.In fact, EuD4TEA has been found to be one of the brightest known TL materials and is a potential candidate for application as an impact sensor.
The purpose of this presentation is to present results from recently completed light yield and prompt fluorescence decay time measurements for EuD4TEA. Emphasis will be placed on current efforts to utilize this data for a variety of potential applications to measure impacts in extreme environments. Basically, EuD4TEA is a material solution looking for a problem.
Low Temperature Synthesis of Nanophosphors for White Light Emission
Authors: Zhang Ying , Dai Qilin 
Published: February 2020

Nanophosphors are considered to be very critical for the development of lighting and display due to some new features from nanosized materials compared to bulk phosphors, for example, surface-site luminescence. The current methods to synthesize nanophosphors are based on high temperature methods, such as hydrothermal method, co-precipitation method, and so-gel method. Usually, temperature dictates the nanocrystals growth speed, which may affect the size and crystallinity of the nanocrystals. pH value is another very important parameter to control the nanocrystal growth, which is believed to be associated with nanomaterial morphology and structure. In our work, we developed a low temperature (2oC) method to synthesize some tungstate nanophosphors, for example CaWO4:Eu, in aqueous solution under different pH values. Nanowires, nanorods, nanospheres are obtained by the developed low temperature synthesis method. Self-assembled microstructures and isolated nanoparticles can be obtained by controlling the pH values. Nanowires are produced as the Eu doping concentration is 10%. For comparison, high temperature synthesis method (150oC) are also used in the synthesis of tungstate nanophosphors. The influence of temperature, pH vales and Eu doping concentrations on the luminescence properties of tungstate nanophosphors are systemically studied, and the mechanism of the luminescence are demonstrated. Small sized nanophosphors are produced as the synthesis temperature is 2oC compared to high temperature. The photoluminescence of CaWO4:Eu includes the green-blue emission band due to the tungstate group in the host and the red emission peaks from Eu3+. The relative intensity of the green-blue emission to the red emission can be considerably tuned by the pH values, which affects the energy transfer efficiency from tungstate group to Eu3+. Eu doping concentration also can be used to adjust the color of the luminescence of tungstate nanophosphors. We optimize the parameters including pH vales, and Eu doping to obtain the white light emission. Figure 1 shows the color coordinates of the nanophosphors prepared by us. It can be seen that the range of color coordinates can be tuned by our method covers blue, green, white, red and yellow regions, which shows the feasibility of our method for the synthesis of nanophosphors toward white light. Low reaction temperature synthesis method provides a platform to synthesize the nanophosphors toward color tunable and while light emission for lighting and display.
Figure 1: color coordinates of the luminescence of CaWO4:Eu nanophosphors

Figure 1
Multifunctional Gel Polymer/Microspheres Composite Electrolyte Coated Separator for Lithium Metal Batteries
Authors: Ryu Saebom , Choi Jang Wook , Sugimoto Toshinori , Lee Yong-Gun , Im Dongmin 
Published: February 2020

Lithium (Li) metal has received much attention as a promising anode candidate in recent years with the increasing demand for high-energy-density rechargeable batteries in industrial fields. However, unlike current graphite anodes where Li ions are intercalated, metallic Li anodes generate Li deposition forming an uneven anode surface and have high reactivity toward organic electrolytes. This can cause safety concerns including cycling instability. Thus, developing a stable electrolyte and its corresponding separator is widely recognized as a major challenge to the practical application of Li metal batteries. Although there remains a need for improving the separator performance because of poor separator wettability for highly viscous electrolytes, little work has been done about the separator structure design to ensure proper wettability and stability [1].
In this study, we propose a high performance composite coated separator for Li metal batteries. A commercial separator was thinly coated with a mixture of block copolymer, ionic liquid, and microspheres. The composite electrolyte coated separator showed significantly enhanced wettability which is sufficient to adsorb highly viscous electrolytes. To improve the mechanical properties of the separator, microspheres with high rigidity and stability to organic electrolyte [2] were used. The tensile strength and thermal stability of the separator were improved by microspheres and block copolymer. This approach appears to be effective in improving battery safety by inhibiting the growth of Li dendrites. Due to the increased wettability and enhanced mechanical properties, the cycle life of the cell was greatly improved when our separator was applied. In addition, unlike the ceramic component with a poor dispersion in the coating solution, our novel coating blend enables cost-effective production with rapid and uniform coatings with its excellent dispersion stability.
[1] M. H. Ryou, Y. M. Lee, J. K. Park, and J. W. Choi, Adv. Mater., 23, 27 (2011).
[2] Y. G. Lee, S. Ryu, T. Sugimoto, T. Yu, W. S. Chang, Y. Yang, C. Jung, J. Woo, S. G. Kang, H. N. Han, S. G Doo, Y. Hwang, H. Chang, J. M. Lee, and J. Y. Sun, Chem. Mater.,
29, 14 (2017).