bluuebunny/crossref_metadata_2025_split huggingface dataset:
CO2-Derived, in-Situ Carbon-Coated Macroporous Silicon As a High Performance Anode Material for Lithium-Ion Batteries
Authors: Cha Younghwan , Dong Panpan , Zhang Xiahui , Song Min-Kyu 
Published: February 2020

The magnesiothermic reduction of silica (SiO2) has been widely explored as a sustainable synthetic route for Si-based anode materials toward advanced lithium-ion batteries. This method utilizes earth abundant SiO2 as a compelling precursor for Si, which is readily attainable from, for example, sea sand, rice husk and diatom frustules. Also, the formation of 3D porous structure via simple removal of magnesium oxide (MgO) is beneficial to improving battery performance since it can help to accommodate 300% volume change during battery operation.
However, many studies have consistently reported incomplete conversion after the synthesis, which is typically in the form of undesirable remnants or side products: unreacted SiO2 and intermediate magnesium silicide (Mg2Si) that need to be chemically removed along with MgO, resulting in active material (Si) loss and uncontrollable porous structure. In addition, to enhance battery performance, it is widely believed that carbon protecting layer should be deposited on Si surface to obtain stable solid electrolyte interphase. The additional process for carbon coating, however, often requires costly and time/energy consuming steps and, therefore, hinders the practical deployment of Si anodes.
To obtain new insights into the incomplete conversion process, we carried out real-time phase evolution studies via in-situ high temperature X-ray diffraction during the magnesiothermic reduction of SiO2 under various thermal treatment conditions. Based on these results, we proposed a novel processing route that can minimize the active material loss and produce in-situ carbon coating on macroporous Si by utilizing gaseous carbon dioxide (CO2) as mild oxidant and precursor for carbon layer. The near-synchrotron X-ray nano-computed tomography was employed to obtain the processing-structure-property relationship. CO2-derived, in-situ carbon coated macroporous Si showed good initial Coulombic efficiency (86%) and high reversible capacity of 2000 mAh/g at 0.2 C-rate with promising cycling performance.
Electronic Structure Elucidation of Two-Step Electrolyte Decomposition Mechanism on Li(x)Mn(1.5)Ni(0.5)O(4) (001) Surfaces
Authors: Leung Kevin 
Published: February 2020

High voltage cathode oxide mateirals like the Li(x)Mn(1.5)Ni(0.5)O(4) spinel can potentially enable high energy density lithium batteries for transportation storage applications. However, they rapidly degrade the organic liquid electrolyte. Customized solvent molecules and passivation coatings/strategies have been devised to alleviate this problem. Drawing from previous theoretical work and new hybrid functional Density Functional Theory (DFT) predictions, we argue in this presentation that the degradation mechanism has more than one step on the spinel (001) surface. First, standard battery liquid solvent molecules already decompose at low potentials, and even on the surfaces of spinel oxides without nickel doping, which operate at modest voltages. The organic fragments cover up catalytically active transition metal sites, yielding a functional form of cathode electrolyte interphase (CEI). Later, at high voltages, the decomposed solvent fragments further break down to release carbon dioxide and other species, leaving the catalytic sites uncovered and leading to continuous reactions with the liquid electrolyte. Mechanistic comparison with organic reactions on platinum surfaces will be made. However, the precise voltage range of breakdown offset cannot yet be predicted. These steps underscore the importance of understanding CEI degradation reaction, not just electrolyte oxidation, and will help inform new passivation strategies to enable high voltage cathode materials.
This work was supported by Nanostructures for Electrical Energy Storage (NEES), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DESC0001160. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525.
Lithium-Ion Battery Safety Tests Monitored By Labview and Comsol Software for Electrical and Mechanical Characteristics
Authors: Sharma Snigdha , Panwar Amrish K , Tripathi Madan Mohan 
Published: February 2020

This paper presents a unique cheaper battery safety test bench for electrical and mechanical performance evaluation of lithium-ion batteries where mechanical performance is tested using software and electrical characteristic is tested using hardware. In this work, simulation of mechanical performance of lithium-ion battery such as thermal modelling test at various temperature has been carried out using Comsol software, where battery voltage and temperature are monitored as a control input during a drive cycle and state of charge of the battery on the positive (65-80%) and a negative electrode (14-29%) is monitored and triggered as a control output. A hardware test bench has been developed to execute various electrical tests for evaluating battery performance during a discharge cycle. These electrical tests have been carried out on the LabVIEW software to obtain the real-time data and display the battery related information such as voltage and current curves. Further, a battery safety test like external short circuit test has been performed and also for improving the battery efficiency capacitors are connected parallelly with varied load condition. Overall, in this exploration, a newly evolved, accurate, affordable battery testing and monitoring system has been developed.
Keywords: LabVIEW Software, Comsol Software, Battery Safety test, Electrical Test, Mechanical Test.
Degradation of Commercial Lithium-Ion Cells Beyond 80% Capacity
Authors: Preger Yuliya , Fresquez Armando , Chalamala Babu R. , Ferreira Summer 
Published: February 2020

To defray the upfront cost of lithium-ion electric vehicle (EV) batteries and to minimize waste, there is substantial interest in repurposing them after their EV end-of-life for grid-related applications (battery second life). The reliability of any economic or technical feasibility analysis for second life batteries strongly depends on the battery degradation behavior, but insight into this degradation in the region of interest remains limited. Most cycling studies in the open literature only age batteries to about 80% capacity (the typical cutoff for marking end-of-life). A few studies that have cycled batteries beyond 80% capacity have suggested the existence of a ‘tipping point’ upon which rapid degradation is initiated, but a limited set of cycling conditions and chemistries were explored.
We have previously reported on our large-scale, multi-year aging study of commercial LiFePO4/LFP, LiNixCoyAl1-x-y­O2/NCA, and LiNixMnyCo1-x-yO2/NMC cells, varying the discharge rate, depth of discharge (DoD), and environment temperature. Now that many of those cells have reached 80% capacity, we have initiated a second life aging study. The advantage of studying these cells compared to those from second-hand EV battery suppliers is that the cycling history is known. Thus, it is more feasible to determine the extent to which prior cycling conditions influence later degradation and the early markers that could foreshadow the possibility of rapid degradation beyond 80% capacity. Diverse cycling conditions were studied to determine what protocols, if any, can mitigate rapid degradation.
Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. SAND2019-4631 A
Detection of Pathogenic Bacteria and Cancer Cells in Body Fluids Using Magnetostrictive Particle (MSP) Biosensors
Authors: Yi Wei , Liu Jiachen , Chin Bryan A. , Cheng Zhongyang 
Published: February 2020

Magnetostrictive particle (MSP) provides sensitive tests for measuring tiny amount of mass and it can serve as a useful device for cell detection and offers potentially effective approaches to clinical diagnosis for detecting bacterial pathogens and early-stage cancer cells. Compared to conventional cells identification methods, MSP biosensor has the advantages of short response time and low cost. It does not require any incubation process thus provides a reagent free direct measurement in practice which does not require any complicated biochemical reactions. Each MSP sensor contains magnetostrictive materials coated with modified antibodies and such structure makes the sensor generate different resonance frequencies in an induced magnetic field after exposure to different concentrations of cells.
Those frequency shifts can be analyzed to determine the presence and concentration of certain bacteria or target human cells in body fluid samples. Here we provide a method to use MSPs to detect two type of cells in body fluids. Staphylococcus aureus is used as an example of common infectious pathogens to human and a breast cancer cell line MDA-MB-231 is used as a example for cancer cells. It is found that the detection limit of MSP sensors for cells can be less than 100 CFU/ml. The results are obtained within a few minutes which makes MSP sensors promising tools in diagnosis of bacterial infections and providing early-stage detection of cancer.

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Conducting Polymer-Based and Electrically Controlled Skin Mapping for Dermatological Diagnostics and Wound Healing Treatment
Authors: Fu Xiaoxu , Ahamed Ashiq , Cheong Yi Heng , Lisak Grzegorz 
Published: February 2020

Novel approach of skin mapping technology was developed and optimized through controlled electrodeposition of conducting polymers (CPs). The CP has excellent flexibility, adequate conductivity and results in a high-resolution pattern of the skin surface. The formed CP pattern entity has distinct 3D structure, which is mirror reflection of target skin surface topology. Ex-situ (off-body) and in-situ (on-body) skin mapping methods were applied (Figure 1) [1], which were done via electropolymerization on a previously sampled skin stamp pattern or directly on the skin surface, respectively. Various 3D entity models of skin patterns, including scars, joint wrinkles, fingerprints and palm of a hand, were successfully developed for the intention to be used in dermatological applications, such as diagnosis, electrostimulation and controlled release of drugs to the pathological skin areas, such as wounds and scars.
This skin mapping approach was proved to have high universality. Skin leaves, in form of sebum, an insulating mark on substrate surface that it is in contact with. Furthermore, if that substrate is electrically conducting, the localized electropolymerization of the CPs in the presence of the insulating pattern (bare conducting metal and insulating mark deposition) resulted in the clear visualization of the skin surface outline (increased contrast between dark CP and unoccupied deposited insulating mark). Pt and Au coated polyethylene terephthalate (PET) films were used as conducting substrate, which provide excellent flexibility, conductivity and smooth surface.
To summarize, this novel conducting polymer-based and electrically controlled skin mapping approach is able to remodel various skin surface patterns and reflect micron-scale 3D structure, which is highly valuable for dermatological diagnostics (Figure 2). The capability of doping and controlled-releasing ions make it even more promising targeted materials for wound care applications.
References
[1] X. Fu, W. Zeng, A.C. Ramírez-Pérez, G. Lisak, 3-D and electrically conducting functional skin mapping for biomedical applications, Chem Commun 54(8) (2018) 980-983.

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Electrochemical Sensor of Gas Phase Iodine
Authors: Perez Carlos R. , Klavetter Kyle Christopher , Coleman Jonathan Joseph , Siegal Michael P. 
Published: February 2020

We report on a nanoelectrode array sensor for the detection of gaseous iodine at levels below 20 ppb within short exposure times. The sensor is constructed on a free-standing anodic aluminum oxide wafer with 120 nm diameter, 50 um length nanopores. On each wafer surface, continuous metal films are deposited: on one surface, a gold film is deposited such that it covers the nanopores, and, on the opposite surface, a platinum film is deposited such that the nanopores remain open and their volumes in contact with the environment. The gold film serves as the working electrode and the platinum film serves as the auxiliary and pseudo-reference electrode. The nanopores are filled with a pH 9 buffer aqueous solution to create an array of billions/cm2 electrochemical cells in parallel. Ionic conductivity is maintained for environments with relative humidity levels greater than ~30%. Here we report on sensor performance improvements that allow using this sensor in more arid environments, as well as in the presence of other relevant interferent analytes (e.g. Cl2).
The detection mechanism is the electrochemical oxidation of anionic species formed by the dissolution and subsequent hydrolysis of gas phase I2 in pH 9 buffer electrolyte. Gas phase I2 dissolves in the buffer following Henry's Law and then is hydrolyzed to several species, including the anionic species iodide and tri-iodide. The hydrolysis mechanism of I2 in the pH 9 buffer enables it to function as a concentrator for the anionic species. When the sensor is exposed to a gas stream containing iodine, continuous accumulation of the electrochemically detectable anionic species is possible, enabling preconcentration of the incoming flow-stream by several orders of magnitude.
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. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.
Electrochemical Signature of Peroxynitrite on Modified Boron-Doped Diamond Electrodes
Authors: Maher Shaimaa , Kalil Haitham , Bayachou Mekki 
Published: February 2020

Endogenous and exogenous reactive oxygen and nitrogen species such as peroxynitrite have serious damaging effects on cell components and cell function. Peroxynitrite has emerged as a reactive species that is linked with oxidation and/or nitration of biomolecules. In biological context, peroxynitrite is the product of the combination between superoxide and nitric oxide radicals through a diffusion-limited reaction. The short lifespan and fast reactivity of peroxynitrite are adding more challenges to measure its concentration under physiologic conditions.
Although several methods have been established for peroxynitrite detection in aqueous solutions, they are still facing the problem of real-time quantification. In this paper, the electrochemical behavior of peroxynitrite has been studied boron-doped diamond electrodes (BDD). Recently, BDD have been successfully worked as platforms for electrochemical detection of various analytes in biological and environmental systems. BDD electrodes provide a wide potential window and a low background current that creates an excellent platform to fine-tune the surface for optimized detection of peroxynitrite.
In this research study, the direct electrochemical oxidation of peroxynitrite on modified BDD electrodes was recorded and investigated. A wide range of physicochemical characterizations were conducted to study the catalytic oxidation of peroxynitrite on modified BDD electrodes. The same modified BBD platform is used to develop a selective peroxynitrite sensor that can further be developed into a tool that can be used for both electrical stimulation and monitoring of peroxynitrite levels under physiologic conditions.
Polyimide-Based Electrodes for Electrochemical Water Splitting and N2 Reduction
Authors: Lin Yun-Xiao , Li Xin-Hao , Chen Jie-Sheng 
Published: February 2020

Polyimide, a commercial organic polymer widely used as electronics coating, is found to have excellent electrochemical catalytic performance in water splitting and N2 fixation recently. Our exciting results are introduced as following two parts:
1.The exploitation of metal-free organic polymers as electrodes for water splitting reactions is limited by their presumably low activity and poor stability, especially for the oxygen evolution reaction (OER) under more critical conditions. Now, the thickness of a cheap and robust polymer, poly(p-phenylene pyromellitimide) (PPPI) was rationally engineered by an in situ polymerization method to make the metal-free polymer available for the first time as flexible, tailorable, efficient, and ultra-stable electrodes for water oxidation over a wide pH range. The PPPI electrode with an optimized thickness of about 200 nm provided a current density of 32.8 mA cm-2 at an overpotential of 510 mV in 0.1 mol L-1 KOH, which is even higher than that (31.5 mA cm-2) of commercial IrO2 OER catalyst. The PPPI electrodes are scalable and stable, maintaining 92% of its activity after a 48-h chronoamperometric stability test.
2.Production of ammonia is currently realized by the high pressure-high temperature Haber–Bosch process, while electrochemical N2 fixation under ambient conditions is recognized as a promising green substitution in the near future. Lack of efficient electrocatalysts for selective fixation and reduction of dinitrogen remains the primary hurdle for the initiation of potential electrocatalytic synthesis of ammonia. For cheaper metals, such as copper, limited progress has been made to date, as the process is theoretically considered not to be energetically feasible. In this work, we boost the N2 reduction reaction (NRR) catalytic activity of Cu nanoparticles, which originally exhibited negligible NRR activity, via a local electron depletion effect. The electron-deficient Cu nanoparticles are brought in a Schottky rectifying contact with a polyimide (PI) support which retards the hydrogen evolution reaction (HER) process in basic electrolytes and facilitates the N2 fixation to aﬀord the electrochemical NRR process under ambient aqueous conditions. This strategy of inducing electron deficiency provides new insight into the rational design of inexpensive NRR catalysts with high selectivity and activity.
Measurement of Macmullin Number for Different Electrochemical Fuel Cell Gas-Diffusion Media Using a Conductivity Cell Apparatus
Authors: Sepe Mitchell , Brizes Michael , Lopata Joseph Steven , Shimpalee Sirivatch , Weidner John W. 
Published: February 2020

The objective of this study is to calculate the MacMullin Number (NM) of various Gas Diffusion Media to improve understanding of the transport through the Gas Diffusion Layer (GDL) for the Electrochemical Fuel Cell Model. In this model, GDL’s are used in the electrolyzer and the fuel cell itself. The outcome of this work will allow for different GDL’s to be compared to each other in a way that the best fit for the Fuel Cell Model can be determined. Experimental data obtained through the Conductivity Cell will allows for the NM to be calculated. The GDL materials used are activated carbon, nickel foam, and nickel mesh. Some samples have the addition of a microporous layer (MPL) to improve transport. A NM calculation allows for the samples with and with out the MPL to be compared. Once an average NM was found for each sample, the data was plotted and a trendline was fit. The trendline was used to compare NM calculation data to previous experimental data. The primary focus of the experiment is the comparison the porosity of the GDL samples verse the calculated MacMullin Number for each sample.
Figure 1 shows the Porosity of various GDL’s plotted against the calculated MacMullin Number. In this figure, GDL’s with an MPL and without an MPL were plotted and the trendline through the data was compared to the Bruggeman equation and the Toray equation. GDL’s containing a MPL tended to have higher NM then the other samples. This happens because the addition of the MPL increases the resistance of the sample. Figure 1 allows for the prediction of different GDL samples NM by using the calculated porosity.
References:

Martinez, Michael J., et al. Measurement of MacMullin Numbers for PEMFC Gas-Diffusion Media. Journal of The Electrochemical Society, 2008, Measurement of MacMullin Numbers for PEMFC Gas-Diffusion Media.

Shimpalee, Sirivatch, et al. Experimental Investigation and Numerical Determination of Custom Gas Diffusion Layers on PEMFC Performance. Elsevier B.V., 2016, Experimental Investigation and Numerical Determination of Custom Gas Diffusion Layers on PEMFC Performance

Martinez, Michael J., et al. Effect of Microporous Layer on MacMullin Number of Carbon Paper Gas Diffusion Layer. Elsevier B.V., 2012, Effect of Microporous Layer on MacMullin Number of Carbon Paper Gas Diffusion Layer.

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Characterization of Gas Diffusion Layers through Computational Fluid Dynamics Modeling and BET Theory
Authors: Brizes Michael , Sepe Mitchell , Satjaritanun Pongsarun , Shimpalee Sirivatch , Weidner John W. 
Published: February 2020

The purpose of this work is to use computation fluid dynamics using mesh simulations to model the flow through gas diffusion layers (GDLs), in order to calculate the fundamental properties of the GDL. The study of porosity, tortuosity, liquid and gas permeability, and pore size distribution for GDL’s are the primary focus points in this work. The GDL model geometries seen in this investigation were obtained through three dimensional reconstructed micro-structures from micro X-ray computed tomography (CT). Figure 1 shows the microstructure and streamlines to model the movement of fluid through the GDL. The simulated GDL’s consist of: EP40T, Sigracet 25BA, Sigracet 25BC, GDS3250, and GDS3260.
The tortuosity calculated from simulations is taken at multiple points on the GDL to obtain an averaged value for the sample. The average value is used because the GDL structure is a matrix of random carbon fibers. The liquid and gas phase permeability is important to the calculation of tortuosity because it is a measure of the willingness of a porous media to flow through it. In addition, the simulated results are compared to experimental data through the calculation of the MacMullin number. The MacMullin number is a relationship defined by porosity divided by tortuosity. This number describes the ionic resistance, or resistance to current flow, through the GDL.
References:

Pal, M.K. Joyce, P.D. Fleming, A Simple Method for Calculation of the Permeability Coefficient of Porous Media, Tappi Journal. (2006).

Martínez Michael J., Shimpalee, S., Van Zee, J.W., 2009. Measurement of MacMullin Numbers for PEMFC Gas-Diffusion Media. Journal of The Electrochemical Society 156. doi:10.1149/1.3005564

Liu, S. Shin, S. Um, Comprehensive Statistical Analysis of Heterogeneous Transport Characteristics in Multifunctional Porous Gas Diffusion Layers Using Lattice Boltzmann Method for Fuel Cell Applications, Comprehensive Statistical Analysis of Heterogeneous Transport Characteristics in Multifunctional Porous Gas Diffusion Layers Using Lattice Boltzmann Method for Fuel Cell Applications. (2018).

Figure 1: Model geometry (EP40T) obtained from Micro X-ray CT with streamlines to show the flow.

Figure 1