bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transition Metal Oxide/ Metal-Organic Framework Hybrid Structures for Efficient Bifunctional Oxygen Electrocatalysis in Alkaline Environments
Authors: Lee Min Hwan 
Published: December 2020

Use of regenerative fuel cells (RFC) requires bifunctionality in oxygen electrocatalysis of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) to decrease weight and cost for efficient energy conversion. Many RFC based technologies have used noble metals such as Pt and its alloys (Pt/Ir or Pt/Ru) due to their efficient catalytic activity, selectivity and stability in harsh environments. However, their susceptibility to fast degradation during operation, as a result of catalyst agglomeration and poisoning, has driven research to find alternatives. Non-precious transition metal oxides (TMO) including Fe3O4, MnOx and Co3O4 have attracted significant attention as a potential candidate [1].
We utilized a hybrid structure where terephthalic acid ligand, cobalt and cerium nitrate salts, and solvents are subjected to a hydrothermal process at 160ºC for 24 h, a phosphoric acid treatment, an atomic layer deposition (ALD) of titania or zirconia, and finally a heat treatment in air. The phosphate group formed by the acid treatment is believed to have formed strong anchoring sites for ALD nanodots on the novel metal organic framework (MOF)-derived structure, which also results in a dispersed distribution of catalytically active sites.
The hybrid catalyst where TiO2 nanodots are uniformly anchored on phosphorylated MOF by ALD showed good ORR and OER performance in 0.1 M KOH in terms of onset/half-wave potential, electron transfer number, and current density when comparing to the performance of Pt/C (for ORR) and IrO2 (for OER). In addition, an activation of catalytic sites can be realized by a proper engineering of interfaces in each hybrid systems. Materials characterization emphasizes a strong adhesion of metal oxides upon MOF structures, thus providing ample surface interactions for favorable reaction route is important.
This project was funded by NASA Advanced STEM Training and Research (ASTAR) Fellowship.
References:
[1] G. Wu and P. Zelenay, Acc. Chem. Res., 46, 1878, 2013.
(Luminescence and Display Materials Division Centennial Outstanding Achievement Award Address) Investigation of Luminescent Materials based on First-principles Calculations of Multiplet States
Authors: Ogasawara Kazuyoshi 
Published: December 2020

The transitions between multiplet states of rare-earth (RE) and transition-metal (TM) ions in crystals are utilized in variety of luminescent materials. Therefore, for the theoretical design of novel luminescent materials, a deep understanding of multiplet states and a nonempirical prediction of multiplet spectra are indispensable. For these purposes, a configuration interaction calculation program based on the discrete-variational Xa (DV-Xa) molecular orbital method [1] was developed, which is known as the discrete-variational multi-electron (DVME) program [2]. There is also a relativistic version of the DVME program [3] based on the relativistic DV-Xa method [4], which is especially useful for the analysis of RE-doped luminescent materials [5] since both the relativistic effects and the many-electron effects can be considered simultaneously without any empirical parameters. The DVME calculations have been applied to analyze various luminescent materials such as ruby [2], Mn4+-doped fluorides [6] and RE-doped LiYF4 [5]. Various types of multiplet spectra originating from d-d, f-f, f-d, and charge transfer (CT) [7, 8] transitions have been reproduced without any empirical parameters and the origins of the spectral peaks have been elucidated based on the configuration analysis of the explicitly obtained many-electron wave functions. In addition, relationships between the multiplet energy and the local structure of TM ions in crystals have been investigated in detail by creating various energy-structure maps based on systematic DVME calculations. The systematic data obtained by first-principles calculations can be also used as the training data for machine learning to create a simple predictive model. In this lecture, some representative results of the investigation of luminescent materials based on first-principles calculations of multiplet states using the DVME program will be presented.
[1] H. Adachi, M. Tsukada, and C. Satoko, J. Phys. Soc. Jpn., 45, 875 (1978).
[2] K. Ogasawara T. Ishii, I. Tanaka, and H. Adachi, Phys. Rev. B, 61 143 (2000).
[3] K. Ogasawara, T. Iwata, Y. Koyama, and T. Ishii, I. Tanaka, and H. Adachi, Phys. Rev. B, 64, 115413 (2001).
[4] A. Rosén, D.E. Ellis, H. Adachi, and F.W. Averill, J. Chem. Phys., 65, 3629 (1976).
[5] K. Ogasawara, S. Watanabe, H. Toyoshima, M.G. Brik, Handbook on Physics and Chemistry of Rare Earths, 37, 1 (2007).
[6] M. Novita, T. Honma, B. Hong, A. Ohishi, K. Ogasawara, J. Lumin. 169, 596 (2016).
[7] S. Takemura, K. Ogasawara, Opt. Mater.: X, 1, 100005 (2019).
[8] S. Takemura, K. Ogasawara, J. Lumin. 214, 116542 (2019).
IR Laser Induced Emission Spectra of GaN Nanoceramic
Authors: Stefanski Mariusz , Gluchowski Pawel , Strek Wieslaw 
Published: December 2020

Currently, the researchers from around the world pay a lot of attention to search new white light generation sources. Such a device would have huge application potential in the lighting industry. The advantage of a broadband white light source is no necessity to mix few emission lines to obtain a white luminescence, as it is in case of the LED devices. Here, we investigate the broadband laser induced emission spectra of GaN nanoceramic measured under three different infrared excitation lines (1064, 975 and 808 nm). The GaN powder was obtained by thermal decomposition method while the nanoceramic was prepared using low temperature high pressure (LTHP) technique. The sample crystallizes in the hexagonal wurtzite structure and theoretical value of their average grain size calculated using Scherrer equation was 12 nm. The optical characterization of LIE spectra of GaN nanoceramic included the measurements of emission intensity as a function of power density, ambient pressure and luminescence kinetics. The emission spectra were recorded in both VIS (400-900 nm) and NIR (1200-2500 nm) regions (Fig. 1a,1b). It was found that the power dependence exhibit threshold behavior typical for avalanche process for all three excitation lines. The luminescence kinetics measurements show that rise and decay times of LIWE are extremely short in comparison to dielectric materials. It turned out that calculated x and y parameters of recorded emissions lie in the warm region of the CIE chromaticity diagram confirming their low color temperature regardless of the excitation wavelength (Fig. 1c). Finally, a general mechanism of LIE spectra in GaN nanoceramic is discussed.
Figure 1. The LIWE intensity of GaN nanoceramic under 975 nm as a function of increasing pumping power density in VIS and NIR regions (a,b). The CIE chromaticity diagram of LIWE generated from GaN nanoceramic upon three various excitation wavelengths (c). The image of LIWE during experiment (d).

Figure 1
The Effect of Anode Slippage on Cathode Cutoff Potential and Degradation Mechanisms in Ni-Rich Li-Ion Batteries
Authors: Dose Wesley , Xu Chao , Grey Clare P. , De Volder Michael F. L. 
Published: December 2020

High energy-density Li-ion batteries based on Ni-rich layered cathodes are the state-of-the-art technologies for electric vehicles. However, batteries using these advanced cathode materials suffer from rapid performance fading and the underlying mechanisms are not fully understood.1 In this work, we report a critical turning point during the aging of graphite/LiNi0.8Mn0.1Co0.1O2 (NMC811) full cells after which the degradation is significantly accelerated. This turning point is identified using differential voltage analysis (DVA)2 applied to standard two-electrode full cell data, which shows a decreased capacity usage of the graphite with cycle number. The graphite becomes progressively less lithiated, as confirmed by operando long-duration X-ray diffraction, and therefore has higher electrochemical potential when the cell has reached the end of charge. As the upper cutoff voltage of the full cell is fixed, this increase leads to a proportional raise of the cathode potential and an accelerated impedance increase is observed from this point. This mechanism is expected to be universal for the vast majority of today’s Li-ion battery chemistries, particularly for Ni-rich cathodes whose degradation is shown to be extremely sensitive to the upper cutoff voltage, and our work provides fundamental guidelines for developing effective countermeasures.
References

Jung, M. Metzger, F. Maglia, C. Stinner, H. A. Gasteiger, J. Electrochem. Soc., 164, A1361, 2017.

Bloom, A. N. Jansen, D. P. Abraham, J. Knuth, S. A. Jones, V. S. Battaglia, and G. L. Henriksen, (2005). J. Power Sources 139, 295 2005.
A New Glass Forming Electrolyte Based on Lithium Glycerolate
Authors: Pagot Gioele , Di Noto Vito , Vezzu Keti , Nale Angeloclaudio , Negro Enrico , Pace Giuseppe 
Published: December 2020

The study of the interplay between structure and conductivity in lithium-conducting electrolytes is a pivotal point for the development of future secondary batteries [1]. The use of Glycerol as a low molecular weight component in electrolytes is particularly interesting due to its glass-forming behavior and low glass transition temperature (-78.5°C). In addition, a high flexibility of the alkyl backbone chain and the well-known capability of oxygen functionalities to coordinate lithium cations make Glycerol very appealing as ion-conducting media as well as building block to obtain hybrid polymer electrolytes [2].
On this basis a family of eleven electrolytes based on Lithium Glycerolate with general formula C3H8-xO3Lix, where 0 ≤ x ≤ 1, is prepared and investigated [3]. In these electrolytes the Glycerolate (C3H8-xO3
x-) component acts as a large and flexible macro-anion which is able to provide a high single-ion conductivity to the material (8.36∙10-5 S∙cm-1 at 20°C and 1.55∙10-2 S∙cm-1 at 150°C for x = 0.25).
Finally, the Glycerol∙∙∙Li+ interactions in these electrolytes are studied on T and x, with a particular reference to the detection of: a) macro-anion coordination sites; and b) the secondary structure of Glycerol chains. Insights on the long-range charge transfer mechanism and Glycerol relaxation events are also discussed.
These studies are carried out by Inductively-Coupled Plasma Atomic Emission Spectroscopy, IR and Raman spectroscopies, DSC, TGA, and Broadband Electrical Spectroscopy.

References

[1] V. Di Noto, S. Lavina, G. A. Giffin, E. Negro, B. Scrosati, Electrochim. Acta 57 (2011) 4-13.
[2] V. Di Noto, M. Vittadello, S. G. Greenbaum, S. Suarez, K. Kano, T. Furukawa, The Journal of Physical Chemistry B 108 (2004) 18832-18844.
[3] G. Pagot, S. Tonello, K. Vezzù, V. Di Noto, Batteries 4 (2018) 41.
TiO2-Core/Sn-Shell Nanotube Arrays Based on Monolithic Negative Electrode for Lithium Ion Batteries
Authors: Kim Hyunsik 
Published: December 2020

The next generation of lithium ion batteries will expand the application range from popular portable devices to high power electric vehicle and so on. For such a use, the cost factor and battery performance in safety, specific capacity and kinetics must be considered and improved. So far as it goes, carbonaceous insertion materials remain leading products for anode materials of lithium ion batteries. However, their reversible capacities are limited to below 372 mAh/g and the kinetic behaviours are also not satisfying. Under such a situation, new anode materials with higher capacity are required.
Recently, one-dimensional (1D) nanostructured materials have received increasing attention in the field of lithium-ion batteries due to large surface-to-volume ratio and contact area between the electrode and electrolyte, which can decrease the electron transport time for both lithium ions and electrons. Furthermore, it can accommodate the strain of lithium ion lithiation/delithiation, enhancing the high capacity and rate capability. Among them, the self-ordered TiO2 nanotubes with high surface-to volume ratios have been extensively examined using electrochemical anodization. These materials are expected to be anode material as a low voltage insertion host of Li and fast Li insertion/extraction host. However, the discharge/charge voltage curves of TiO2 nanotubes were suppressed by their conductivity with low degree. In order to improve the conductivity of TiO2 nanotubes, the carbon doping by the pyrolysis of C2H2 gas was performed. Also, Sn/TiO2 composite duplex nanotube is prepared by sputter method to enhance total discharge capacity and its electrochemical performance was evaluated by constant current discharge/charge, cyclic voltammetry, and electrochemical impedance spectroscopy.
The Role of TiO2 Particles on the Ion Conduction Mechanism in Polyether Electrolyte Having Cyanoethoxy Sidechain
Authors: Hitaka Tasuku , Isobe Ryutaro , Matsuoka Riho , Yamada Koki , Sai Ryansu , Katayama Yu , Tsutsumi Hiromori 
Published: December 2020

Although solid-state polymer electrolytes (SPE) have attracted much attention as a safe electrolyte material for lithium-ion batteries (LIB), one major limitation of SPE resides in the low ionic conductivity[1]. Previous study reported the improvement of ionic conductivity by adding inorganic particles into polymer electrolytes[2]. However, a molecular-level understanding of its effect on the Li+ conduction mechanism is still lacking.
In this study, we select polyether having cyanoethoxy sidechain as a polymer matrix, and clarify the effect of TiO2 nanoparticles on the Li+ conduction mechanism. Differential scanning calorimetry and thermogravimetric analysis confirmed that glass transition temperature (T
g) and the thermal stability of electrolytes were not affected by TiO2. On the other hand, electrolyte with TiO2 showed higher ionic conductivity than the electrolyte without TiO2. Various (electro)chemical and spectroscopic analyses were performed to clarify the key descriptor for the ionic conductivity. Infrared spectroscopy confirmed that the Li+–CN interaction was not affected by the existence of TiO2. However, it also suggested two types of the dissociated anion (free anion and anion interacting with the surface hydroxyl group on TiO2) in the electrolyte with TiO2. Based on these results, observed improvement of Li+ conduction for TiO2-contained electrolytes can be due to the trapping of bulky anion by surface hydroxyl groups on TiO2.
In conclusion, we clarify that the anion trapping by the surface hydroxyl group on TiO2 nanoparticles could facilitate Li+ conduction, probably due to the absence of bulky anion, which sterically inhibits Li+ transportation. The surface hydroxyl groups on inorganic fillers thus play a vital role in facilitating Li+ conduction.

[1] X. Zhigang et al., J. Matter. Chem. A, 2015, 3, 19218–19253.
[2] F. Croce et al., Nature, 1998, 394, 456–458.
Effects on Interfacial Resistance Using LICGCTM in the Cathode
Authors: Katoh Takashi , Satoh Ryouhei , Nakajima Kousuke , Hoffman Brion 
Published: December 2020

Lithium ion batteries are widely used in electric devices and electric vehicles due to their excellent performance at high power and the high energy density they provide compared to other conventional batteries. The application for electric vehicles is expanding worldwide as our society moves towards a lower carbon footprint but the lithium ion battery technology still needs further improvements in terms of physical properties, output, durability and safety. Current lithium ion batteries also degrade with charge–discharge cycles and storage time. In the cathode, low retention capacity, accompanied by the growth of resistive thin films and crystal structure deterioration on the surface of the active materials, remain unsolved problems. Modifications to the cathode surfaces have been researched and proven as effective measures to improve durability. Surface coatings on lithium‐ion battery cathodes improve their durability. Solid oxide materials like MgO, ZrO2 and SiO2 are applied or processed on to the cathode active materials by sol-gel, PVD or mechanochemical treatments and the solid oxide layer plays a role as an artificial solid electrolyte interface. The solid oxide coating layer prevents contact between the electrolyte and the active materials thus inhibiting the redox process and leading to an improvement in the cycle performance of the battery.
We confirmed the LCO cathode containing a small % of Ohara lithium ion glass ceramic (LICGCTM ) PW-01 powder showed less deterioration and transition metal reduction at high temperature (60℃). The LICGCTM PW-01 powder was produced using a glass melting and ceraming method. A Li 2O-Al 2O 3-TiO 2-P 2O 5 glass was prepared and converted into glass-ceramics through heat-treatment. The lithium ion conductivity of the glass-ceramic with Li 1 + x
Al
x
Ti 2 − x
(PO 4) 3 phase is extremely high 1 × 10 −3 Scm −1 at room temperature. We found that adding LICGCTM PW-01 powder in the cathode had other significant effects, including increasing the battery capacity at high rate and at low temperature (-20℃). We also verified via by EIS measurement that the LICGCTM PW-01 powder additive significantly reduced the charge transfer resistance. The use of the LICGCTM PW-01 powder as a cathode slurry additive can serve an important role in improving the performance of lithium ion batteries.
Three-Dimensional Resistivity Quantification and Visualization of Silicon-Based Composite Anode Nanostructure Via Scanning Probe Microscopy
Authors: Stetson Caleb , Downard Ali , Huey Zoey , Jiang Chun-Sheng , Al-Jassim Mowafak M. , Finegan Donal , Han Sang-Don , DeCaluwe Steven C. 
Published: December 2020

Nanocomposite Si-graphite electrodes are a viable option for increasing the energy density and life of lithium-ion battery anodes. In comparison to model systems (e.g., Si wafer and Si thin film), Si nanoparticles, ranging in diameter from tens to hundreds of nanometers, have higher rate capacity and improved fracture toughness.1, 2 However, characterization efforts to better understand localized degradation mechanisms and heterogeneous aging behaviors of distinct components—Si, graphite, binder, and conductive carbon—in Si-based nanocomposite anodes through cycling are hindered by the limited information that can be achieved at the nanoscale using traditional microscopy techniques.
To date, high resolution, three-dimensional structural visualization of the Si-based composite electrode has relied upon techniques like X-ray nano-computed tomography3, 4, that provide morphological information but not electronic or chemical information. In this work, we report a novel lab-scale scanning probe microscopy-based approach to map the 3-D nanostructure of composite anodes via contrast in their components’ intrinsic electronic properties. By incorporating experimental nanoscale electronic resistivity data through interpolation, volumes can be extracted to represent distinct constituent phases of the composite electrode. This approach presents an opportunity for relatively high throughput, nanoscale characterization of composite anodes and cathodes to investigate phenomena such as particle dispersion in electrode preparation and electrode evolution through cycling. Ultimately, this technique shows future utility for the multiscale understanding of structural evolution and degradation processes within lithium-ion batteries.
Figure 1: Interpolated resistivity layers captured within a Si-Carbon(C) composite electrode, processed to extract C-rich and Si-rich volumes.

R. C. de Guzman, J. Yang, M. M.-C. Cheng, S. O. Salley, and K. Y. Simon Ng, Journal of Materials Science,
48 (14), 4823-4833 (2013).

S.-L. Chou, J.-Z. Wang, M. Choucair, H.-K. Liu, J. A. Stride, and S.-X. Dou, Electrochemistry Communications,
12 (2), 303-306 (2010).

O. O. Taiwo, M. Loveridge, S. D. Beattie, D. P. Finegan, R. Bhagat, D. J. L. Brett, and P. R. Shearing, Electrochimica Acta,
253 85-92 (2017).

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3 (10), (2019).

Figure 1
Chemistry, Microstructure, and Interphases of Magnesium Metal Anodes Captured Via Cryogenic Electron Microscopy
Authors: Long Daniel M , McClary Scott A , Hahn Nathan T , Zavadil Kevin R , Jungjohann Katherine L 
Published: December 2020

Lithium-ion batteries are an important component in mobile electronics; however, their modest energy density makes them less than ideal for use in all-electric vehicles or localized grid residential/commercial energy storage. Multivalent-ion batteries (MIBs), including Mg2+, are promising high-energy density technologies that are cheaper and more abundant than lithium. Realizing the high theoretical energy density of MIBs requires the native multivalent-ion metal to be used as the anodic electrode, where densely controlled metal plating and stripping has yet to be achieved. The mechanisms governing plating/stripping of MIBs and the resulting microstructural impact on the battery performance must be understood before MIBs can be employed commercially. Understanding the role that the solid electrolyte interface has on multivalent-ion metal plating/stripping may lead to solutions for controlling reversible anodic cycling.
Recent advances in cryogenic electron microscopy(cryo-EM) preparation have allowed for scanning transmission electron microscopy (STEM) investigation of intact solid/liquid interfaces and electron-beam-sensitive materials. Here we present results of our chemical and microstructural investigation of plated and stripped Mg2+ anodes, collected with cryo-FIB preparation, cryo-transfer, and cryo-STEM. Details will be presented on the anode porosity, grain orientation maps, chemical maps from the electrode/electrolyte interfaces, and high-resolution structural imaging of the electrode interfaces.
This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. DOE’s National Nuclear Security Administration under contract DE-NA-0003525. The views expressed in the article do not necessarily represent the views of the U.S. DOE or the United States Government.