bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metal Deposition on Graphene Layers and Electrochemical Measurements at Liquid/Liquid Interface: Preparation of Graphene-Based Metal Nanostructures
Authors: Toth Peter S , Dryfe Robert AW 
Published: February 2020

Polarisable liquid/liquid interfaces have been investigated for over 30 years, mainly in the context of ion and electron transfer reactions. Electrical polarisation of the interface between two immiscible electrolyte solutions (ITIES) generates electrochemical potential gradients capable of promoting ion and electron transfer across the molecular boundary. The potential drop across the liquid/liquid boundary is developed over a region of 1 to 10 nm. The nucleation of metallic structures, catalytic activity e.g. hydrogen and oxygen evolution, the assembly of nanoparticles or catalytic nanoparticles have received a great interest in the last years.1-2

Graphene nanomaterials were prepared in two ways: gravity exfoliation from natural graphite in 1,2-dichloroethane (DCE) dispersion and chemical vapor deposition (CVD) on copper foil. Both types of material were assembled at the interface between two immiscible electrolyte solutions. The graphene materials before and after assembly were characterized by Atomic Force Microscopy (AFM) and Raman spectroscopy. The electrochemical reactivity of assembled graphene materials was probed by model redox species at the ITIES.

In situ electrochemical and spontaneous metal deposition of palladium, gold and silver at the interface assembled carbon nanomaterials were studied. The identification and morphology of the deposited metal was determined using electron microscopy. The 2D graphene-based metal nanostructures effects were studied for the model redox species process at the ITIES.
The graphene-metal composites preparation procedure at the ITIES opens an alternative way to prepare catalyst materials. Deeper understanding of the behavior of model redox couples on graphene is of primary importance in the exploitation of this material in catalytic processes, such as of the oxidation of low molecular weight alkanes to liquid fuels.
1. Fermin, D. J.; Ding, Z.; Duong, H. D.; Brevet, P. F.; Girault, H. H., Journal of Physical Chemistry B, 1998, 102, 10334-10341.
2. Dryfe, R. A. W., Physical Chemistry Chemical Physics,
2006, 8, 1869-1883.
Graded Density Ion Exchange Polymer Films on Electrodes: Impacts on Structure and Transport
Authors: Knoche Krysti L. , Leddy Johna 
Published: February 2020

The full expression of Fick’s second law includes a distance dependent diffusion coefficient, D(x). In one dimension, for distance x and time t, the concentration is expressed as shown in Equation 1.
Eyring models for transport as a function density and viscosity are predicated on an activation energy for short distance hopping of the diffusing species from one low energy site to an adjacent site of similar low energy. This results in a correlation between density and viscosity.
In turn, the Stokes Einstein relationship (Equation 2) specifies diffusion coefficient and viscosity η are inversely related. Equation is for a spherical diffusion species of radius r, k is the Boltzmann constant, T is temperature. If viscosity varies in space as η(x), then D(x) varies in space proportional to 1/η.
Ficoll® (GE Life Sciences) is a highly branched, water soluble, hydrophilic copolymer of sucrose and epichlorohydrin that is used to establish density gradients. On application of Ficoll films to electrodes, the density gradient is preserved. Cyclic voltammetry of outer sphere redox probes such as tetramethylphenylenediamine yields near steady state responses as scan rate slows. Modeling of the voltammetric responses establishes that the density gradient establishes a steady state flux of materials to the electrodes. Images of Ficoll films immersed in solution confirm a density gradient.
Here, Ficoll is used as a template to form a graded film of the ion exchange polymer, Nafion® (DuPont). Films are formed on electrodes by cocasting Ficoll and Nafion. Alternatively, a cast film of Ficoll can serve as the template for the Nafion. Films are evaluated by imaging. When compared to a uniform Nafion film, cyclic voltammograms for outer sphere redox probes that pass through the ion exchange polymer are altered. Sigmoidal as well as Gaussian voltammograms are observed, dependent on conditions of film formation. The structural morphology changes imprinted on formation of Ficoll Nafion layers alters flux through the ion exchange polymer layer.

References and Acknowledgments: Support of the National Science Foundation and the University of Iowa is gratefully acknowledged. Thanks also to Dick Buck for his example as a thoughtful scientist and mentor.
[1] Krysti L. Knoche and Johna Leddy, manuscript in preparation.
[2] K. L. Knoche, P. D. Moberg, C. Hettige, and J. Leddy, "Simulation of Fick's Second Law for Spatially Variant Diffusion Coefficients," ECS Trans. (2013) 53 (15) 1-6.
Mechanical Method of Lithium-Ion Soh and SOC Measurement
Authors: Cannarella John , Arnold Craig B. 
Published: February 2020

Despite the fundamental importance of state of health and state of charge determination in battery management systems, measurement of SOH and SOC is difficult and remains an area of active research. In this presentation we propose a novel approach to lithium-ion battery cell management which makes use of observed relationships between cell expansion and SOH/SOC to determine the SOH and SOC of a cell during operation using simple stack stress measurements.
We first present results from an aging study of constrained commercial lithium-ion pouch cells in which we observed an irreversible increase in stack stress during cycling [1]. The increase in stack stress is due to irreversible expansion of the solid battery electrodes against the rigid constraint of the cell housing. This increase in stack stress is not a result of gas evolution, as the same stress increase is observed in pouch cells with a slit cut in the pouch and cycled under argon atmosphere.
Plotting the stack stress against the SOH of the cell reveals a linear relationship between stack stress and SOH during cycling, as shown in Figure 2. This suggests a fundamental coupling between irreversible electrode expansion and capacity fade. By monitoring this irreversible expansion during cycling—either through stress or strain measurements of the pouch cell—we show that it is possible to determine the cell’s SOH from simple mechanical measurements. The simplicity of these measurements and their relationship to SOH offer many advantages to the current state of the art.
We also show that the same mechanical measurements can be used to determine the cell’s SOC by measuring reversible changes in the cell stress/thickness with cycling. The measured stress can be related to the SOC of the cell if the SOH is known. Stress measurements are advantageous to voltage measurements for determining SOC because voltage measurements are strongly affected by battery usage via overpotentials. This mechanical method of SOC determination is computationally simpler than Coulomb counting and is also able to account for discharge events such as internal short circuiting that Coulomb counting is unable to detect.
FIGURE CAPTIONS
Figure 1. Stress evolution of a constrained pouch cell during cycling showing an irreversible increase in stack stress.
Figure 2. Stack stress plotted against state of health shows a linear relationship between the two parameters.
Figure 3. Stack stress plotted against SOC at different states of health of the constrained pouch cell.
REFERENCES
[1]. J. Cannarella, C. B. Arnold, “Stress evolution and capacity fade in constrained lithium-ion pouch cells,” J. Power Sources
245(2014) 745-751.
ACKNOWLEDGEMENTS
Support was provided by the DoD through the NDSEG Program and by the Siebel Energy Challenge. J. C. also acknowledges the Rutgers-Princeton IGERT in Nanotechnology for Clean Energy.
Electrochemical Stress Measurements of Potential Induced Structural Changes in Sn Anodes for Li Ion Batteries
Authors: Tavassol Hadi , Gewirth Andrew 
Published: February 2020

We report on electrochemical surface stress measurements of thin film Sn electrodes for Li-ion battery anodes at potentials <2.0 V vs. Li/Li+. In most anodes, mechanical changes are dominated and controlled by Li-host interactions. Graphite, Si, and a Au model system exhibit compressive stress resulting from Li insertion. Calculations support these experimental results. Anodes experience tensile stress resulting from Li removal. This tensile stress may create cracks, and cause capacity loss.
In contrast, Sn surfaces exhibit major compressive and tensile surface stress changes even before Li insertion. These features originate in conversion reactions between SnOx on the electrode surface and Li forming Sn and LiOx. During the cathodic scan, an intense compressive feature at ca. 0.7 V vs. Li/Li+ is observed. A major tensile release at ca. 0.6 V vs. Li/Li+ follows this compressive feature. Changes in the amount of oxygen in the surface film affect the electrochemical stress measurement dramatically, while having a more modest impact on the voltammetry. The SnOx/Li conversion reaction impacts the ability of Sn and its alloys to serve as an anode material for a Li ion battery.
We also report the results of matrix assisted laser desorption (MALDI) time of flight (TOF) mass spectrometry (MS) analysis of Sn electrodes. In a mixture of ethylene carbonate and dimethyl carbonate, long chain oligomers are observed following the first cycle. These oligomers are decomposed in the subsequent cycles showing that Sn surfaces form an unstable SEI. This decomposition results in oligomerized species, which are different from those formed at the end of the first cycle. We will discuss potential and solvent dependent oligomerization mechanisms and their effect on mechanical properties of Sn electrodes.
Prediction of Lithium Ion Cell Cycle Life By Coupled Chemical and Mechanical Degradation Modeling
Authors: Hasan Mohammed , Barai Pallab , Mukherjee Partha P. 
Published: February 2020

Lithium-ion batteries (LIB), owing to their unique characteristics with high power and energy density, are broadly considered as a leading candidate for vehicle electrification. However, the limited cycle life, particularly during fast charging process, is a pivotal performance drawback of LIB. The irreversible formation of the Solid Electrolyte Inter-phase (SEI) at the anode particles surface is identified as a key aging mechanism for these batteries causing capacity loss and resistance rise [1]. Intercalation and deintercalation of Li ions inside the active particles generate significant amount of stress which leads to fracture. Formation of cracks creates new surface area during cycling. These fresh surfaces act as catalysis for SEI formation. At high charge or discharge rates, the diffusion induced fracture and crack propagation exacerbate that results in a higher side reactions rates [2]. Although the tremendous progress in using mathematical models in predicting the cycle life, limited studies have coupled the chemical and the mechanical aspects in cyclic life predictions. The significance of the coupling is manifested during high charge and discharge rates, that the intense intercalation poses high mechanical stresses to fracture the electrode.
In this study, we are investigating the influence of the coupled chemical and mechanical degradation mechanisms on the cycle life of LIB. The computational method comprises of; a first principle capacity fade model for chemical degradation predictions and a stochastic diffusion induced fracture for mechanical damage predictions incorporated in the single particle model [3, 4]. The coupled model is envisioned to present a fundamental elucidation of the high degradation and poor performance during fast charging and discharging rates.

V. Agubra, J. Fergus, Materials, 6 1310–1325 (2013).

J. Li, E. Murphy, J. Winnick, P.A. Kohl, J. Power Sources, 102, 160 (2001).

P. Barai and P. P. Mukherjee, J Electrochem Soc, 160 (6), A955 - A967 (2013).

R. Deshpande, M. Verbrugge, Y-T. Cheng, J. Wang, and P. Liu, J. Electrochem. Soc., 159 (10) A1730-A1738 (2012).

G. Ning, B. Haran, and B. N. Popov, J. Power Sources, 117, 160 (2003).
Deep TEM Study of Ageing Mechanisms of Li-Ion Batteries Associated with Renewable Energies
Authors: BEN Hassine Mohamed 
Published: February 2020

The main objective of the ANR Vision project is to propose Li-ion batteries for energy storage application associated with renewable energy with a lifetime of 15-20 years. The scientific goal is to improve knowledge of long time aging mechanisms according to use conditions. This understanding would be helpful for improvement of prototypes that will be tested during the project. Batteries made of Li[Ni1-x-yMnxCoy]O2(NMC) and carbon a are investigated.
Electron microscopy techniques (Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), High Resolution-High Angle Annular Dark Field (HR-HAADF), Focused Ion Beam (FIB), Electron Dispersive Spectroscopy (EDS) and Electron Energy Loss Spectroscopy (EELS)), were deeply used to determine the degradation of the aged active materials: stress, strain, fracture, phase transformations, dissolution resulting from intense cycling.
By comparison of pristine and cycled materials, SEM investigation on FIB electrode slices revealed detachments and cracks inside and between active material and the binder (Figure 1) as well as preferential dissolution [1] of transition metal (EDS). SAED patterns show the creation of defects and highlight a transition phase from lamellar to spinel phase (Figure 2-A). In order to nicely visualized spinel domains [2, 3], images were recorded on a FEI Cs-corrected Titan Ultimate microscope fitted with HR-HAADF camera (Figure 2-B).
Afterwards, all these results, combined with information recorded by the other VISION partners, are used to make recommendations to create new generations of prototype cells.
[1] Nicholas P. W. Pieczonka et al., J. Phys. Chem. C 2013, 117, 15947−15957.
[2] A. Boulineau et al.,Chem. Mater. 2012, 24, 3558−3566.
[3] D. Mohanty et al., Journal of Power Sources 229 (2013) 239-248.
Acknowledgement: This work was funded by ANR (Agence Nationale de la Recherche) and is part of the VISION project.
Invited Presentation: Strong Nonlinear Photoluminescence Properties of Trions and Localized Excitons in Single-Walled Carbon Nanotubes
Authors: Matsuda Kazunari , Miyauchi Yuhei 
Published: February 2020

Recently, the optical properties of carrier-doped single-walled carbon nanotubes (SWNTs) have been extensively studied [1-3]. We describe nonlinear photoluminescence (PL) properties of excitons and trions (charged excitons) in hole-doped SWNTs. We found that the PL intensity of the trions in hole-doped SWNTs exhibits a strong nonlinear saturation behavior as the excitation density increases, whereas that of the excitons shows a weak saturation behavior. The strong PL saturation of the trions is attributed to the state filling of trion states due to the limited number of doped holes. Moreover, the radiative lifetime of the trion was evaluated to be about 180 ns, which indicates that the experimentally observed PL from the trions originates from partially dipole-allowed transition in a SWNT. We will also discuss the nonlinear PL properties of localized excitons in oxygen-doped SWNTs [4,5].
[1] R. Matsunaga, K. Matsuda, and Y. Kanemitsu , Phys. Rev. Lett. 106, (2011) 037404. [2] J. S. Park, Y. Hirana, S. Mouri, Y. Miyauchi, N. Nakashima, and K. Matsuda, J. Am. Chem. Soc. 134, (2012) 14461.[3] S. Mouri, Y. Miyauchi, M. Iwamura, and K. Matsuda, Phys. Rev. B 87, (2013) 045408.[4] S. Ghosh, S. M. Bachilo, R. A. Simonette, K. M. Beckingham, and R. B. Weisman, Science, 330 (2010) 1656.[5] Y. Miyauchi, M. Iwamura, S. Mouri, T. Kawazoe, M. Ohtsu, and K. Matsuda, Nat. Photonics 6, (2013) 547.
Invited Presentation: Unifying the Low Temperature Luminescence Spectra of Carbon Nanotubes
Authors: Vialla Fabien , Chassagneux Yannick , Lauret Jean-Sébastien , Voisin Christophe 
Published: February 2020

Photo-excited electron-hole pairs in carbon nanotubes form strongly bound and localized excitons that can recombine radiatively giving rise to near infrared luminescence signals. Due to the coupling to acoustic phonons, this PL line was predicted to be strongly broadened (even at low temperature), leading to asymmetrical meV-broad phonon sidebands. In addition, due to the peculiar one-dimensional geometry, the (possibly narrow) zero phonon line (ZPL) is completely merged into the phonon wings resulting in an overall broad and asymmetric PL line [1]. This picture was recently puzzled by the observation of ultra narrow PL lines in suspended nanotubes [2,3] raising questions about the electron-phonon coupling mechanisms. Here, we show that ultra narrow PL lines can also be observed for regular micelle wrapped nanotubes deposited on a substrate. However, a high resolution measurement allows to identify attenuated sidebands that are reminiscent of the one-dimensional electron-phonon coupling. This observation allows to interpret both the narrow and the broad lines in terms of modified electron-phonon coupling in a unified framework [4].
[1] Galland et al. PRL 101, 067402 (2008)
[2] Hofmann et al., Nature nano. 8, 502 (2013)
[3] Sarpkaya et al., Nature comm. 4, 2152 (2013)
[4] Vialla et al., submitted
Endohedral Fullerene Derivatives: Tether-Directed Functionalizations and Regioisomer Preferences
Authors: Echegoyen Luis , Izquierdo Marta , Ceron Maira 
Published: February 2020

Addition reactions have been performed (carbene and addition-elimination, Bingel) on Sc3N@C2nto determine the preferred mono- as well as multiple addition positions both experimentally and via computations. It has been observed that carbene additions lead to many more isomers than the corresponding addition-elimination reactions of malonates (Bingel reaction), which lead to a rather small number of regioisomers. Theory predicts well the Bingel adducts that are observed experimentally and provides a kinetic rationale for the observations.
Tethered bis-additions have also been explored, especially on Lu3N@C80, and the results indicate very regioselective bis-additions, with only one bis-regioisomer observed in many cases for bis-carbene additions.
These and other results will be presented and discussed within the context of single and multiple functionalization of endohedral fullerene compounds and how the properties of the products can be controlled via functionalization.
Carbon Nanotube NIR Fluorescent Probes
Authors: Okazaki Toshiya 
Published: February 2020

In clinical tests, detection of weak signals is especially important for detection of low concentration biomolecules. An enzyme-linked immunosorbent assay (ELISA) is often employed for antigen detection, where background fluorescence that is generated from the combination of autofluorescence from serum components and nonspecific binding serum proteins, limits detection sensitivity of an antigen by ELISA.
Near-infrared (NIR) fluorescence has attracted much more interests in diagnostic fields because of the lower background interference and the improved tissue penetration. Several NIR fluorescent molecules have been tried in enzymatic assays, DNA sequencing, capillary electrophoresis, immunoassay and so on. For example, by using NIR fluorescent nanoparticles, alpha fetoprotein was successfully detected even in whole-blood samples, which indicates a great advantage of NIR labels in clinical tests. Under these circumstances, novel NIR fluorescent molecules for biological label have so far been synthesized.
Single-walled carbon nanotubes (CNTs) have received much attention due to their superior mechanical, optical, thermal and electrical properties. In particular, CNTs have been considered as ideal labels for biological imaging in vitro and in vivo because CNTs show fluorescence in the wavelength region of 1000−1400 nm, so-called the second NIR window. In this wavelength region, indigenous tissue autofluorescence is much lower than that in the visible (400−750 nm) and shorter NIR (750−900 nm) regions, which enables clear vascular imaging with the CNT labels. This benefit is further enhanced by a large Stokes shift between emission and excitation resonances of CNTs, leading to further suppression of endogenous autofluorescence. Moreover, CNT photoluminescence does not show photobleach under prolonged duration of excitation as compared with NIR fluorescent dyes and quantum dots.
In the present work, to show the potential ability of the CNT labels in the immunological tests, we conjugated CNTs with immunoglobulin G (IgG) antibodies by using a linker molecule of phospholipid polyethylene glycol (PEG), and their immunoprecipitation using protein G magnetic beads was examined [1]. The combination of IgG and protein G was adopted because they specifically bind with each other. The present results, using CNTs as the NIR fluorescent labels for the immunoassay, will pave a new way for medical applications of CNTs.

Y. Iizumi, T. Okazaki, Y. Ikehara, M. Ogura, S. Fukata and M. Yudasaka, ACS Appl. Mater. Interfaces, 5, 7665−7670 (2013).
A Complete Guide on the Influence of Metal Clusters in the Diels-Alder Regioselectivity of Ih
-C80 Endohedral Metallofullerenes
Authors: Garcia-Borràs Marc , Osuna Sílvia , Luis Josep Maria , Swart Marcel , Solà Miquel 
Published: February 2020

The chemical functionalization of endohedral metallofullerenes (EMFs) arouses considerable interest for the possibility to synthesize new species with potential applications in materials science and medicine. Experimental and theoretical studies on the reactivity of endohedral metallofullerenes are scarce. To improve our understanding of the endohedral metallofullerene reactivity, we have systematically studied with density functional methods the Diels-Alder cycloaddition between s-cis-1,3-butadiene and practically all X@Ih
-C80 EMFs synthesized up to date: X = Sc3N, Lu3N, Y3N, La2, Y3, Sc3C2, Sc4C2, Sc3CH, Sc3NC, Sc4O2, and Sc4O3.1,2 We have studied both the thermodynamic and the kinetic regioselectivity, taking into account the free rotation of the metallic cluster inside the fullerene. This systematic study has been made possible through the use of the Frozen Cage Model, a computationally cheap approach to accurately predict the exohedral regioselectivity of cycloaddition reactions in EMFs. Our results show that the reactivity of all metal clusters studied is lower than that of the hollow Ih
-C80 cage. Except for the Y3 cluster, the addition takes place predominantly over the [5,6] bond. In many cases, however, a mixture of the two possible regioisomers is predicted. In general, the [6,6] addition is favored in EMFs that have a larger charge transfer from the metal cluster to the cage or have a voluminous metal cluster inside. The present investigation represents the first complete and exhaustive guide on the reactivity of Ih
-C80 based EMFs.
[Figure 1 here]
1. M. Garcia-Borràs, S. Osuna, J.M. Luis, M. Swart, and M. Solà, Chem. Eur. J. 2013, DOI: 10.1002/chem.201302202.
2. S. Osuna, R. Valencia, A. Rodríguez-Fortea, M. Swart, M. Solà, J.M. Poblet, Chem. Eur. J. 2012, 18, 8944.