bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glucose Sensor Using NAD-Dependent Glucose Dehydrogenase, Diaphorase, and Osmium Complex
Authors: Nam SangWook , Yang Haesik 
Published: May 2020

It is still challenging to detect glucose selectively in serum and blood, and quickly using nicotinamide adenine dinucleotide (NAD-GDH). In this paper, we report a selective and rapid glucose sensor, based on electrochemical-enzymatic-enzymatic (ENN) redox cycling involving bis(2,2-bipyridyl)dichloroosmium(II)[Os(bpy)2Cl2], diaphorase (DI), NAD+, NAD-GDH, and glucose. DI and Os(bpy)2Cl2 are used to obtain fast mediated oxidation of NADH that is generated as a result of glucose oxidation by NAD-GDH. DI and NAD-GDH are co-immobilized via affinity binding on an avidin-modified indium tin oxide electrode to obtain fast and stable ENN redox cycling. Two enzymes (DI and NAD-GDH) and two electron mediators [Os(bpy)2Cl2 and NAD+] are efficient. The reason is that they are insensitive to oxygen. The applied potential (0.0 V vs Ag/AgCl) is low enough to minimize interfering electrochemical reactions, and the redox reactions of Os(bpy)2Cl2 with interfering species are slow. NAD-GDH is much less reactive to problematic monosaccharides such as xylose, fructose, galactose, and mannose than glucose. Artificial serum containing 5% (w/v) human serum albumin shows a similar electrochemical back-ground level in serum. All results enable us to obtain selective and reproducible glucose detection. The fast ENN redox cycling allows sensitive glucose detection with a wide range of concentrations in artificial serum with a short measuring time (5 s) without an incubation period.
Keywords: Glucose sensor, Glucose dehydrogenase, Diaphorase, Osmium complex
Low-Voltage STEM-Eels Quantification for Lithium Ion Battery Material Characterization
Authors: Dumaresq Nicolas , Gauvin Raynald , Zaghib Karim 
Published: May 2020

In material sciences, in order to develop new compounds with different electrical, mechanical or optical properties we need to understand the link between these properties and the microstructure of the material. This apply also to understand the decrease of efficiency of a battery after multiple charge-discharge cycle where the structural changes need to be identify in order to prevent it. Scanning transmission electron microscopy (STEM) has been proven to be a powerful tool for the study of microstructure and morphology with a subnanometer resolution. Furthermore, a STEM paired with electron energy loss spectroscopy (EELS) can provide useful information on the specimen elemental composition. However, these technique are normally used with a high electron beam voltage (80-200 keV) and the high energy of the electron beam induce beam damage into low Z materials such as lithium compound. This becomes problematic when the microstructure of a LIB is observed since the change into the material cause by the beam damage is close to the changes cause by the use of batteries during cycling. To prevent beam damage such as knock-on damage, the electron beam voltage need to be reduce to relatively low kV. However, no work on low voltage EELS quantification has been reported.
This study will present the acquisition of EELS spectrum using a state-of-the-art dedicated transmission scanning electron microscope (Hitachi-SU9000EA) at 30 keV. Low-voltage EELS quantification on standard will be presented using the integration ratio method. Interesting results will be presented on the inelastic cross-section measurement at low-voltage with the combination of convergent beam electron diffraction(CBED) and EELS. Theses values will be compared with the cross-section obtain using computational calculation that are normally used for high voltage EELS quantification.
Prediction of Temperature in a Penetrated Lithium-Ion Pouch Cell Using a Multi-Physics Model
Authors: Lee Soon-Kyu , Choi Jin Hyeok , Kim Charn-Jung , Lee Kyu-Jin 
Published: May 2020

Recently safety studies have been actively conducted for large capacity lithium-ion batteries (LIB) used in various industry fields, not only electric vehicle (EV) but energy storage system (ESS) and etc. However, these large LIB cells more can bring critically dangerous explosive accidents in larger scales than small LIB cells. Thermal runaway, the common event before the LIB explosion, is caused by many reasons such as overcharge, internal and external short circuits and self-reaction heating at high temperature.
Many numerical studies have been conducted to thermal behaviors of LIBs for safety. However, experimental tests of the safety incidents are usually hard to be reproduced and controllable so that experimental data has been lacked. In this situation, multi-physical models can produce electrochemical responses and electrical- thermal behaviors of LIBs which experience the safety problems. Using numerical models, thermal risks in various short-circuit circumstances can be predicted.
In this study, we will represent an electric- electrochemical-thermal (EECT) model to estimate thermal behaviors of LIB cells in internal short circuit situations. This multi- physics model considers charge conservation, thermal energy conservation in cell volumes and also calculates electrochemical reactions at active electrodes using the pseudo-2-dimension method (P2D). The model calculates electrical current paths through the nail penetrating the cell and Ohmic heat generated by the electric currents.
Using the EECT model, a large capacity LIB cell was simulated for a nail penetration case. The design of the cell was chosen to be similar to that of the cells in the industrial fields like energy storage system (ESS) or EV. The cell has about 20Ah capacity and graphite (LiC6) and layered nickel metal oxide (LiNi0.5Co0.2Mn0.3O2, NCM523). The size of the nail was 5mm by 5mm and made of still. Also, parametric studies about nail size, location, and state of charge (SOC) of the cell were conducted and the parametric data was used for providing the safety guidelines at the short-circuit situations.

Figure 1
Mechanisms of Stable Cycling 3D Structured Anodes for Lithium Metal Batteries
Authors: Zhang Rui , Shen Xin , Chen Xiao-Ru , Chen Xiang , Cheng Xin-Bing , Zhang Qiang 
Published: May 2020

Lithium (Li) metal is among the most promising anode materials in next-generation high-energy-density energy-storage-systems due to its ultrahigh theoretical specific capacity of 3860 mAh g−1 and low negative electrochemical potential (−3.040 V vs. the standard hydrogen electrode). However, Li dendrite growth, “dead Li” formation and unstable solid electrolyte interphase (SEI) have hindered its practical applications.
3D Structured lithium metal anodes, which possess customizable conductive framework for electron transfer and designable pore structures for ion transfer, have been widely proposed to settle these issues. We have constructed several carbon material based structured anodes to investigate the mechanisms in dendrite-free plating morphology, “dead Li”-free stripping morphology, and many other issues for achieving stable cycling 3D structured anodes. Based on the unstacked graphene framework, we found that the ultralow local current density induced by the high specific surface area of unstacked graphene can make great progress for stable and high-performance lithium metal anodes. Furthermore, with lithiophilic nitrogen-doped graphene framework, metallic Li nucleation can be regulated, then even plating morphology can be achieved. When apply the similar lithiophilic surface to a structural stable skeleton like carbon fibers, both Li dendrite growth and “dead Li” formation can be inhibited, and ultimately a high Coulombic efficiency can be achieved for high-capacity and high-rate Li metal batteries.
However, the mechanisms of stable cycling 3D structured anodes which can guide the design of lithium metal anodes are heavily lacking due to the grand challenges of current trial-and-error investigation based on complex materials innovation. If a quantitative theoretical analysis can be proposed, reliable lithium metal anodes with 3D host is highly expected. Thus, theoretical calculation such as phase field models are also employed to quantitatively describe the lithium plating and stripping process in various conductive structured lithium anodes. We found that structured lithium metal anodes with larger areal surface area and smaller pore-volumetric surface area can be much better for high rate and high capacity battery cycling.
Beyond the design and adjustment of lithium metal anodes, further experiments and simulations are required in revealing the mechanisms in lithium metal anodes, such as Li plating and stripping process, dendrite growth, SEI formation and its impact, etc., not only for 3D structured anodes. These mechanism investigations are promising for high-energy-density lithium metal batteries like Li–S and Li–O2 batteries.
Toward High Areal Capacity Lithium Batteries Via 3D Printing: From Liquid to Solid
Authors: Gao Xuejie , Sun Xueliang 
Published: May 2020

3D-printing has found wide applications in numerous research fields, ranging from mechanical engineering, medicine, and material science to chemistry. Among them, it is capable of fabricating electrodes with high active material loading and improved ion/electron conductivity, and is thereby a promising method to improve the energy and power density of energy storage systems. And this technique offers a fresh viewpoint in designing high loading cathodes and will arise interest in other energy storage devices such as Li-ion batteries, Li-S batteries, and Li-Se batteries, etc. In this talk, I will talk about 3D-printed high active material loading cathode applied in batteries: from liquid to solid.
In the first part of this talk, I will introduce 3D-printed high S loading cathode applied in liquid-based Li-S batteries. Compared with conventional cathode fabrication method, a 3D-printed S cathode with grid structure, which could facilitate Li+/e- transport at the macro, micro and nano scale in Li-S batteries. Moreover, a thickness-independent S cathode structure is also proposed via converting thick electrode into thousands of vertically aligned thin electrode by 3D printing. And each thin electrode delivers a constant thickness of around 20 μm, which is not affected by the intrinsic thickness of electrode as well as sulfur loading. Compared with other high S loading Li-S batteries performace, this work demonstrate a similar electrochemical kinetics in spite of the total sulfur loading or thickness of the electrode. [1-2]
In the second part of this talk, I will talk about 3D-printed ultra-high Se loading cathode applied in solid-state Li-Se batteries. Compared with other Li-Se work, this work exhibits excellent cycling stability and remarkable rate performance with the highest reported Se loadings of 20 mg cm-2, and also delivers the highest reported areal capacity of 12.99 mA h cm-2 under a current density of 3 mA cm-2. The 3D-printed Se cathodes with grid structure provide large spaces for polymer electrolyte impregnation to further build interconnected Li+ transport channels in thick electrodes, enabling fast Li+ transport in solid-state Li-Se batteries. [3]

References

[1] X. Gao, X. Sun* et al,
Nano Energy
, 2019, 56, 595-603.
[2] X. Gao, X. Sun* et al,
Energy Storage Mater.
Doi.org/10.1016/j.ensm.2019.08.001.
[3] X. Gao, X. Sun* et al,
J. Mater. Chem. A
, under revision.

Figure 1
Understanding the Electrocatalytic Solid-Liquid Interface: The Early Years of the Więckowski University of Illinois Research Group
Authors: Myers Deborah J. 
Published: May 2020

Andrzej Więckowski was an Assistant/Associate Professor of Chemistry at the University of Illinois Urbana-Champaign from 1985 to 1996 and a Full Professor from 1996 to 2012. Andrzej had a unique ability to attract students to his research group due to his infectious enthusiasm, boundless energy, and excitement for science and cutting-edge experimental approach. This talk will focus on the early years of Andrzej’s tenure at the University of Illinois and his pioneering research in probing the composition and structure of electrocatalytic solid-liquid interfaces using ultra-high vacuum techniques (Figure 1), radiochemistry, and electrochemical nuclear magnetic resonance spectroscopy.
Figure 1. (left) The first ultra-high vacuum instrument in the Andrzej Więckowski University of Illinois, Urbana-Champaign research group and (right) Andrzej, 1987.

Figure 1
Mixed-Metal-Oxide Based Hybrid Electrocatalytic Materials for Efficient Reduction of Carbon Dioxide
Authors: Kulesza Pawel J. , Rutkowska Iwona Agnieszka 
Published: May 2020

Of particular interest to the preparation of advanced catalytic materials is efficient utilization of catalytic sites (metal and metal oxide nanostructures, their stabilization and intentional activation, as well as organization into two-dimensional arrays, ultra-thin films or three-dimensional networks (e.g. through sequential deposition) on electrode surfaces. They can form nanosized materials with well-defined composition, structure and thickness that exhibit desirable electrocatalytic properties (e.g. toward reduction of CO2). We explore here the ability of polynuclear inorganic metal oxo systems to stabilize and functionalize metal (e.g. copper) nanostructures. Here certain nanostructured metal oxides of zirconium, titanium, zinc or tungsten have been demonstrated to influence supported metal centers in ways other than simple dispersion over electrode area. Evidence is presented that the support can modify activity (presumably electronic nature) of catalytic metal nanoparticles (e.g. Cu, Ag, Au, Pd, Ru) thus affecting their chemisorptive and catalytic properties. Metal oxide nanospecies can generate –OH groups at low potentials that induce proton mobility at the photo(electro)chemical interface.
Our research interests concern development of systems for the electrocatalytic reduction of carbon dioxide not only in neutral but also in acid media. For example, nanosized Cu or Ru naoparticles immobilized within ultra-thin films of tungsten oxide or zirconia have been considered. Selectivity of the catalytic systems largely depends on the activing adsorptive (CO2) phenomena and the affinity of catalytic centers to the adsorbed carbon monoxide (CO) type intermediates leading to their protonation or hydrogenation. Reduction of carbon dioxide begins now at less negative potentials and is accompanied by significant enhancement of the CO2-reduction current densities relative to the competitive hydrogen evolution.
The Vanadium Redox Reactions – Electrocatalysis or Not?
Authors: Wang Jiabin , Stimming Ulrich 
Published: May 2020

Catalytic effects of surface groups on porous carbon electrodes are claimed in literature for the redox reactions V(II)/V(III) and V(IV)/V(V). The literature is critically analysed also in relation to work of this group. A method on how to overcome the problem of assessing the electrochemically active surface area on porous electrodes is presented [1]. Applying this method, no catalytic effects for above reactions can be substantiated. It is further pointed out that the parameters electrochemical potential and temperature need to be used to assess electrocatalysis.
The main control parameter determining the rate of an electrochemical reaction is the Gibbs free enthalpy of activation, ΔG≠
, in contrast to ΔH≠
for e.g. a heterogeneous surface reaction. This would suggest to clearly define electrocatalysis as the “lowering the activation barrier, ΔG≠
, in an electrochemical reaction” where, in fact, the lowering of ΔG≠
can result from a change in ΔH≠
and/or ΔS≠
(∂
ΔG≠
/∂η=∂
ΔH≠
/∂η−T∂ΔS≠/∂η
, as in Figure1). Such a treatment of data of temperature dependent electrochemical reactions has been described in literatures [2,3]. An analysis according to the above-discussed procedures would pin down which quantity is responsible for the lowering of ΔG

≠
that may allow for a better interpretation of the electrocatalytic effect.
Using the example of the redox reactions V(II)/V(III) and V(IV)/V(V) the literature was analysed regarding possible catalytic effects of functional groups on carbon electrodes, as in Figure2. The conclusion was that no electrocatalysis of either of these reactions can be confirmed. Observed enhancements of currents can rather be attributed to a change in the effective surface area of the, usually, porous electrode. A method is suggested how such effects can be distinguished from electrocatalysis by using electrochemical impedance spectroscopy (EIS). Figure2 gives an example how EIS data are used for evaluation. In more general terms, the criteria for electrocatalysis were described. Experimentally, an investigation should contain both, measurements of the potential dependence and the temperature dependence since the main parameter in electrocatalysis is the lowering of ΔG≠
. Only then, the respective influence of ΔH≠
and ΔS≠
can be assessed.
Acknowledgments
This work was supported in part by Siemens AG through a research grant and by EPSRC through funding for the North East Centre of Energy Materials (NECEM) (EP/R021503/10).
References:
[1] U. Stimming, J. Wang, and A. Bund, ChemPhysChem, 2019, 20, 1-7.
[2] B. E. Conway, In Modern Electrochemistry, Vol. 16. New York: Plenum Press, 1987.

[3] Z. Borkowska, M. Cappadonia, and U. Stimming, Electrochim. Acta, 1992, 37(3), 565-568.
[4] J. Friedl, C. M. Bauer, A. Rinaldi, and U. Stimming, Carbon, 2013, 63, 228-239.

Figure 1
Exploring Fuel Cell Catalyst Layers at Multiple Scales
Authors: Zawodzinski Thomas A. , Subbaraman Ram 
Published: May 2020

The catalyst layer used in a fuel cell is an archetype of multi-component composite materials used as electrodes in many electrochemical devices. In this talk, we will describe and link together a number of studies of the fuel cell catalyst layer that we have been carried out over the past 10 to 15 years. A major focus of the talk is work on a MURI project with Andrzej Wieckowski together with other ‘all-stars’ in the field. This project combined experiment and theory to evaluate electrocatalysis. We will discuss this effort and Andrzej’s critical role in some of the accomplishments of the team.
We will emphasize our work on describing the geometrically constrained limits on utilization of dispersed catalyst in the layer. To answer our original question, the catalyst components were broken down to constituents (Pt nanoparticles, carbon particles, ionomer) and interactions between components were used to build a hierarchical model of the catalyst layer. The interactions were defined in the context of colloidal interaction theory using descriptions of electronic properties of the constituents derived from experimental measurements of refractive index/dielectric properties across a wide range of frequencies. The model satisfactorily captured some aspects of the structure of the catalyst layer, e.g. the tendency toward segregation of components, and provides a good bound to the utilization of catalysts but failed to provide a quantitatively accurate description of certain transport-related physical properties.

Acknowledgement

We are humbled and honored to have enjoyed the collaboration and scientific spirit of Andrzej Wieckowski as well as his gracious support of our team effort. We gratefully acknowledge the support of this work by the US Army Research Office and the Naval Research Research Office. The significant contributions of Professor J. Adin Mann of Case Western Reserve university and Dr. Karren More of Oak Ridge National Lab are also appreciated.
Oxygen Reduction Reaction Mechanism Study Via the Mean-Field Microkinetic Modeling and Uncertainty Quantification of Model Parameters
Authors: Kurilovich Aleksandr Andreevich , Stevenson Keith J. 
Published: May 2020

Electrocatalytic oxygen reduction reaction (ORR) finds important applications as the cathodic reaction in hydrogen fuel cells or metal-air batteries. However, its slow kinetics even on the most active catalysts requires an understanding of the reaction mechanism for the cost-effective catalyst search.
The first insight into the reaction mechanism can be obtained via the rotation ring disk electrode experiment (RRDE), which can be used to extract information about the reaction kinetics. A substantial amount of experimental work has been carried out in this field with various reaction mechanisms proposed. In many cases, they show a similar level of agreement with the experimental data, because ORR is a complex reaction, while the only intermediate observed experimentally is H2O2 (HO2
- in alkali). More accurate results may be obtained within the mean-field microkinetic modeling approach (MF-MKM). It is built upon the Butler-Volmer formalism for the charge-transfer steps, the law of mass action for the chemical steps, mass transfer equations for the reaction intermediates in the electrolyte, and various interactions between the adsorbed species (Langmuir, Frumkin, and Temkin isotherms).
However, for the complex reactions, even the simplest numerical models have numerous parameters, such as forward/backward rate constants of the proposed reaction steps. They are usually adjusted manually, or fitted to the experimental data using the local optimization methods. The main drawback of both these approaches is that one should have prior knowledge of the approximate model parameters, i.e. guess the reaction pathway. While being successful for relatively simple models, it can be hardly done for the more complicated cases. Additionally, the uncertainty in the estimated model parameters is introduced from the errors in experimental data.
In this work, we describe the quantitative framework for the reaction mechanism selection based on model parameters uncertainty quantification via the Tree-Structured Parzen estimator algorithm and accuracy of fitting of available experimental data by the suggested reaction mechanism within the MF-MKM formalism. So it provides the elucidation of the reaction mechanism which can be considered based on the available experimental data and should be crucial to study the reaction mechanism of ORR and other sufficiently complex reactions.