bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Industrial Electrochemistry and Electrochemical Engineering Division Student Achievement Award Address) Fundamental Understanding on Cell Performance Enhancement of Flow Batteries with Serpentine Flow Field Structures
Authors: Ke Xinyou , Savinell Robert F. , Wainright Jesse S. 
Published: February 2020

Redox flow batteries are being considered for medium and large-scale stationary energy storage applications. In addition to storing energy by the intermittent resources, such as tide, wind and solar energy, the electrochemical flow battery systems could impact electricity generation and grid effectiveness by supporting energy storage for peaking shaving, load leveling and emergency back up [1,2]. In recent years, flow field designs, such as a serpentine flow field, evolved from proton exchange membrane (PEM) fuel cell have been experimentally demonstrated to deliver improved cell performance and boost cell capacity [3] as compared to flow batteries without flow field designs. However, the mechanisms causing enhanced higher limiting current density with serpentine flow field designs have not been fully understood. In this presentation, I will introduce a concept of maximum current density associated with the stoichiometric availability of the pressure-driven electrolyte flow penetrating into the porous carbon electrode from the from the serpentine flow channel [4-6]. Our three-dimensional model demonstrates that this maximum current density concept can explain the observed limiting current density achieved in a flow battery with a serpentine flow field structure [7]. We hope this fundamental understanding can contribute to a better elucidation of the mechanism on limiting the electrochemical performance and further optimization of flow batteries.

Acknowledgement

This work was partially supported by the “all-iron flow battery” project with a grant number of DE-AR0000352 funded by the program of the Advanced Research Projects Agency-Energy (ARPA-E) of the Department of Energy (DOE) of the United States. I (XK) would like to acknowledge the late Professor Joseph M. Prahl, who was my advisor and inspirational mentor.

References

[1] A.Z. Weber, M.M. Mench, J.P. Meyers, P.N. Ross, J.T. Gostick and Q. Liu, J. Appl. Electrochem., 41: 1137-1164, 2011
[2] X. Ke, J.M. Prahl, J.I.D. Alexander, J.S. Wainright, T.A. Zawodzinski and R.F. Savinell, Chem. Soc. Rev., DOI: 10.1039/C8CS00072G, 2018
[3] D.S. Aaron, Q. Liu, Z. Tang, G.M. Grim, A.B. Papandrew, A. Turhan, T.A. Zawodzinski, J. Power Sources, 206: 450-453, 2012
[4] X. Ke, J.I.D. Alexander, J.M. Prahl and R.F. Savinell, J. Power Sources, 270: 646-657, 2014
[5] X. Ke, J.I.D. Alexander, J.M. Prahl and R.F. Savinell, J. Power Sources, 288: 308-313, 2015
[6] X. Ke, J.M. Prahl, J.I.D. Alexander and R.F. Savinell, Electrochim. Acta, 223: 124-134, 2017
[7] X. Ke, J.M. Prahl, J.I.D. Alexander and R.F. Savinell, J. Power Sources, 384: 295-302, 2018
A Study of Dark TiO2 Coating on Pure Titanium By Micro Arc Oxidation
Authors: Hong Yu-Fang , Lee Howard , Lin Hsin-Chih 
Published: February 2020

Dark TiO2 coatings on Titanium have attracted scientific interest due to their extensive applications such as decorative architectures and optical equipment for solar collectors. Several methods have been reported to prepare successfully the dark TiO2 coatings, such as conventional anodizing, cathodic polarizing, and micro arc oxidation (MAO). It is well known that MAO is a new technique for generating surface oxide coatings on valve metals and alloys, including Titanium, Aluminum and Magnesium. Actually, MAO technique has several advantages for surface coating, such as strong adhesion, high hardness, superior wear and corrosion resistance. However, the dark TiO2 coatings on Titanium prepared by MAO are still seldom reported.
The present study investigated the dark TiO2 coating on pure Titanium by MAO technique. For the MAO process, a bipolar pulsed power supply with appropriate electrical parameters, and a phosphate-based electrolyte with vanadium compound as colorant were used. Experimental results indicated the MAO coatings on pure Titanium are mainly composed of TiO2. These MAO coatings exhibit homogeneous dark color and good surface protection, including the corrosion and wear resistance. In this study, the effects of electrical parameters and various electrolytes on the dark TiO2 coatings will also be systematically discussed, including the surface morphology, microstructure and property of wear and corrosion resistance.
Iron Controllable Lithium into Lithiotropic Carbon Fiber Fabric: A Novel Li Metal Anode with Improved Cyclability and Dendrite Suppression
Authors: Niu Junjie , Chen Xi , Lv Yingying , Shang Mingwei 
Published: February 2020

The Department of Energy (DoE) announced the >500 Wh/Kg even 600 Wh/Kg target of the energy density for next-generation lithium-ion batteries in the incoming 3-5 years, to meet the rapidly growing market in electrical vehicles (EVs) and portable electronic devices. In order to reach this goal, Li metal, is considered as the most promising candidate as anode (Xu, Energy Environ Sci 2014). However, the dendrite forming, low Coulombic efficiency, and unstable solid electrolyte interphase (SEI) pose big challenges in applying Li metal in batteries (Chandrashekar, Nat Mater 2012).
Herewe report a novel, single-side Li-infused carbon fiber fabric (LiCFF) with a controllable, minimized Li loading, which shows a highly reversible plating/stripping with a low overpotential of less than 50 mV (Li foil: >1.0 V over 50 cycles) in symmetric cells up to >3000 cycles (>6000 hours) (Energy Environ Sci, under review). Full cell batteries using the LiCFF as ‘all-in-one’ anode without additional slurry-making process and nickel-manganese-cobalt oxide (NMC) as cathode exhibit an improved capacity retention when compared with Li foil: 32% at 0.5 C and 119% at 1.0 C capacity improved after 100 cycles. In parallel, the mossy/dendritic Li on the LiCFF was largely suppressed, which was confirmed using in-situobservations of Li plating/striping in a capillary cell. The stable, uniform deposition of a thin, controllable Li layer on CFF using a facile ironing method lead to form a reversible, dendrite-free Li metal electrode, which enables practical applications in Li-metal based batteries such as Li-S, Li-O2, and Li-transition metals.
Polypropylene Carbonate Based Solid Polymer Electrolytes for Lithium Ion Batteries
Authors: LaCoste Jed , Campo Nicholas , Ardoin Sydney , He Zizhou , Guo Hui , Fei Ling 
Published: February 2020

Lithium ion batteries are promising as energy storage devices because of their high energy density; however, current technology for lithium ion batteries is not safe for large scale applications and general use. Traditional lithium ion batteries utilize an organic liquid electrolyte to transport lithium ions between electrodes. Organic liquids used in lithium ion batteries, such as diethyl carbonate, are highly flammable and volatile. Safety becomes an issue when the battery heats from charging, discharging, or if the battery shorts circuits due to dendrite formation in the cell; when this happens, the battery can potentially ignite. For this project, the research focus is developing novel solid polymer electrolytes for lithium ion batteries. Polypropylene carbonate (PPC), a copolymer of propylene oxide and carbon dioxide, has emerged as a promising candidate for solid polymer electrolytes (SPE) because of its good chemical stability, ionic conductivity, low flammability, as well as environmental friendliness. A versatile air-controlled electrospray technique is used to directly deposit PPC based electrolyte on cathodes with a selected range of thickness. Directing casting electrolyte films on electrode can greatly enhance the interface contact and lower ion transfer resistance. The composition of the SPE can be simply controlled by tuning the polymer solution. The thickness can be controlled by either the deposition time or flow rate.
Several tests are to be performed to characterize the electrolyte material as well as battery performance. These tests include cyclic voltammetry, Fourier Transform Infrared Spectroscopy, AC Impedance Spectroscopy, and Scanning Electron Microscopy. The impact of solid electrolyte film on lithium dendrite formation are also monitored and analyzed.
Phase Inversion Strategy to Flexible Freestanding Electrodes: Critical Coupling of Binders and Electrolytes for High Performance Li-S Battery
Authors: Wahyudi Wandi , Chao Zhen , Kumar Pushpendra , Li Mengliu , Wu Yingqiang , Hedhili Mohammed N. , Cavallo Luigi , Li Lain-Jong , Ming Jun , Anthopoulos Thomas D. 
Published: February 2020

Development of flexible and freestanding electrode is fascinating for lithium-sulfur (Li-S) batteries to enable higher gravimetric energy density and wider potential applications. However, the lithium polysulfides shuttle effect remains challenging and leads to a severe capacity fading. Here, we study the sulfur cathode prepared via phase inversion method with polyethersulfone (PES) polymeric binder and the coupling strategy of the electrode with polysulfide-modified electrolyte to enhance the cells performance. The flexible/freestanding electrode was successfully prepared by the efficient and straight forward method, even it is possible for massive production of electrodes with various size. The resultant polymeric networks in the electrode can effectively trap the soluble polysulfides owing to the higher hydrophilicity and stronger affinity of PES than that with the routine polyvinylidene fluoride (PVDF) binder. Furthermore, we show a two-fold enhancement of the cell performance by coupling the electrode with polysulfide-modified electrolyte, giving an improved capacity of 1141 mAh g-1, lower polarization of 192 mV and more stable capacity retention with 100% Coulombic efficiency over 100 cycles at 0.25C. The advantages of favored strategy are further demonstrated in lithium-ion sulfur full battery with lithiated graphite anode, which demonstrates much improved performance than those previously reported. This work successfully introduces an efficient strategy for flexible/freestanding electrodes and enlightens the importance of coupling strategy to enhance the performances of Li-S batteries.
Figure 1. (a) Digital photographs of the as-prepared composite via phase inversion method. (b) Cycle performance of half-cells using 2-layer PES-CNT-S and PVDF-CNT-S cathodes with polysulfide(PS)-free electrolyte and polysulfide(PS)-modified electrolyte at 0.25C.
REFERENCES

W. Wahyudi, Z. Cao, P. Kumar, M. Li, Y. Wu, M. N. Hedhili, T. D. Anthopoulos, L. Cavallo, L. J. Li, J. Ming, Adv. Funct. Mater., 2018, 28 (34), 1802244.

Ming, Z. Cao, W. Wahyudi, M. Li, P. Kumar, Y. Wu, J. Y. Hwang, M. N. Hedhili, L. Cavallo, Y. K. Sun, L. J. Li, ACS Energy Lett., 2018, 3 (2), 335-340.

Wang, Z. Cao, G. A. Elia, Y. Wu, W. Wahyudi, E. Abou-Hamad, A. H. Emwas, L. Cavallo, L. J. Li, J. Ming, ACS Energy Lett., 2018, 3 (12), 2899-2907.

Figure 1
Ionic Liquid-Based Electrolytes for High-Voltage Li-Ion Batteries
Authors: Liu Qian , Jiang Wei , Li Ying , Pupek Krzysztof Z. , Piernas-Muñoz María José , Bloom Ira , Zhang Zhengcheng 
Published: February 2020

The lithium-ion battery (LIB) with high energy density is highly demanded for electric vehicle application. To increase the energy density of LIB, one popular approach is to elevate the operation potential of the cathode or the voltage of the cell. However, at high potentials or high voltages, the state-of-the-art (SOA) organic carbonate-based electrolytes tend to be oxidatively decomposed at the cathode surface causing gassing issue, low Coulombic efficiency, transition metal ion dissolution and rapid capacity fade of the full cell. In this presentation, we studied the piperidinium-based ionic liquids as an electrolyte candidate for high-voltage lithium-ion battery due to their low melting point, low vapor wide electrochemical window, nonflammability and low/non-volatile merits.
When doped with various amount of lithium fluorosulfonylimide salt (LiFSI), the piperidinium-FSI- based ionic liquid showed much improved cycling performance in the NMC532/Li cells at voltages higher than 4.5 V compared with the SOA electrolyte - 1.2 M LiPF6 EC/EMC (3/7 wt.). The feasibility as a practical electrolyte for the next generation LIB was evaluated by its physical properties and electrochemical stability on both cathode and anode. Furthermore, Raman spectroscopy and molecular dynamic simulations (MD) were conducted shedding light on the sophisticated 3D-network structure containing piperidinium cation, FSI- and Li+ species at various LiFSI concentrations.
Symmetric and Asymmetric Capacitive Deionization Cells Using Modified Porous Carbon Electrodes
Authors: Gao Xin , Omosebi Ayokunle , Landon James , Ma Zilong , Ghorbanian Mahyar , Kern Neil , Liu Kunlei 
Published: February 2020

Capacitive deionization (CDI) is an emerging approach to water treatment that makes use of common porous carbon materials to electrostatically remove ions from a solution.(1-3) Desalination using CDI is achieved in a flow cell consisted of a minimum of a pair of porous carbon electrodes separated by a water channel as sketched in Fig. 1(a). Often, constant-voltage operation is adopted to investigate ion transport of a CDI cell with a charging voltage (V
ch) for ion adsorption and a discharge voltage (V
dis) for ion desorption.(2)Details are illustrated in Fig. 1(b) by using an ionic charge curve plotted in a potential distribution diagram, where the ionic charge curve is defined by the modified Donnan (mD) model with chemical surface charge for a single carbon electrode according to reference (4, 5).
Ion adsorption-desorption by a CDI cell depends upon the placement of the potential of zero charge (E
PZC) versusE
oin a potential distribution diagram,(6)where E
PZC commonly defines a potential when the electrode has a minimum in ion adsorption,(7)as depicted at the lowest point on the ionic charge curves in Fig. 1(b). In this work, by modifying carbon surface chemistry using carbon oxidation, scenarios of different E
PZCversus E
o are created to investigate the effect of carbon surface charge on ion adsorption-desorption of a CDI cell. A comprehensive study will be performed to demonstrate the importance of the E
PZCparameter in a potential distribution diagram on resulting adsorption-desorption characteristics, primarily including real-time measurements of the potential drops at the CDI electrodes during charging and discharging, and developments of a new approach to estimate the E
PZCaccording to the mD model with chemical surface charge.

References

J. Landon, X. Gao, B. Kulengowski, J. K. Neathery and K. Liu, J. Electrochem. Soc., 159, A1861 (2012).

X. Gao, J. Landon, J. K. Neathery and K. Liu, J. Electrochem.Soc., 160, E106 (2013).

A. Omosebi, X. Gao, J. Landon and K. Liu, ACS Appl. Mater. Interf., 6, 12640 (2014).

X. Gao, A. Omosebi, J. Landon and K. Liu, J. Phys. Chem. C, 122, 1158 (2018).

P. M. Biesheuvel, H. Hamelers and M. Suss, Colloids Interf. Sci. Commun., 9, 1 (2015).

E. Avraham, M. Noked, I. Cohen, A. Soffer and D. Aurbach, J. Electrochem. Soc., 158, P168 (2011).

A. J. Bard and L. R. Faulkner, Electrochemical Methods - Fundamentals and Applications, John Wiley & Sons, New York (2001).

Acknowledgement

This work is supported by the Crosscutting Research, National Energy Technology Laboratory, U.S. Department of Energy (DE-FE0031555).

Figure 1
Luminescence and Magnetic Properties of Porous Silicon Investigated with Respect to Its Metal Filling
Authors: Granitzer Petra , Rumpf Klemens , Poelt Peter , Reissner Michael 
Published: February 2020

The influence of magnetic metal filling on the optical and on the magnetic properties of luminescent porous silicon (PSi) is presented. The metal deposits affect, depending on their amount, the optical behavior but also give rise to specific magnetic properties. Due to the metal filling of the porous silicon the photoluminescence is blue-shifted and furthermore an increase of its intensity is observed. The modification of the optical properties, especially of the photoluminescence and its life time and the magnetic characterization of the nanocomposits is elucidated. First the optical properties of the luminescent PSi are investigated, second Ni is deposited electrochemically within the porous silicon samples and subsequently the nanocomposite specimens are characterized optically again and also magnetically. The samples are structurally characterized by SEM, EDX and TEM.
Photoluminescence spectra of bare PSi show a maximum around 620 nm whereas in the case of Ni filled samples the peak is blue-shifted to around 580 nm and the luminescence intensity is increased. The observed blue shift of the photoluminescence peak with increasing metal deposition time and the enhancement of the photoluminescence intensity as well as a decrease of the photoluminescence life time can be interpreted by a decrease in the radiative life time. The enhancement of the photoluminescence intensity is interpreted by the coupling of the silicon emitter to the Ni plasmons. Due to the direct vicinity of the emitter and the metal structure, only separated by a thin SiO2 native layer, coupling of the plasmonic modes with the emitter can occur [1].
Concerning the magnetic properties of the nanocomposite the embedded Ni structures can be superparamagnetic from the size of the pore diameters but due to the branched morphology the achieved deposits tend to be interconnected and thus do not offer necessarily a superparamagnetic behavior [2]. Also temperature dependent magnetization measurements give no hint for superparamagnetism. Field dependent magnetization measurements performed with the magnetic field applied perpendicular and parallel to the sample surface show a high magnetic anisotropy. It can be clearly seen that the samples offer a film-like behavior due to the interconnected Ni structures which is represented by the easy axis parallel to the surface. The magnetic properties of the Ni filled PSi also offer a dependence on the amount of deposited metal. An increase of the deposition time meaning an increase of the metal amount within the porous layer leads to more interconnected metal structures. This behavior is evidenced by the enhancement of the coercivity and the magnetic anisotropy.
The presented systems are promising candidates for applications in optoelectronics and also for magneto optical integrated devices.
[1] A. Huck, U.L. Anderson, Nanophotonics (2016), 5, 1.
[2] G. Bertotti, Hysteresis in Magnetism, 1st Edition, Academic Press, 1998.
(Invited) Perspectives on Computational Studies of Electrocatalysis: New Approaches to Theoretical Catalyst Design
Authors: Greeley Jeffrey 
Published: February 2020

Advances in the theoretical understanding of interfacial electrochemistry have, over the past decade, permitted the extension of periodic Density Functional Theory studies, which have traditionally been applied to probe chemistry at gas/solid interfaces, to electrochemical systems where potential-dependent structural and chemical phase transformations occur at liquid/solid interfaces. Indeed, such techniques have been employed to study a surprisingly wide class of electrochemical processes, ranging from electrocatalysis to corrosion, and are now being used to identify promising candidates for new electrocatalytic materials.
In this talk, I will begin with an overview of DFT-based predictions of electrocatalytic reaction mechanisms, with a particular focus on the Oxygen Reduction Reaction (ORR), which, given its mechanistic simplicity, has been a particularly fruitful target for computational research. I will summarize the several classes of materials that have been computationally investigated for this chemistry and will also seek to link recent results with experimental testing in practical membrane electrode assemblies. In the second part of the talk, I will describe some new methods that are being developed to increase both the fidelity and efficiency of computational electrocatalytic models, and I will provide examples of how these approaches are now yielding insights into electrocatalytic reactions with greater mechanistic and structural complexity.
(Invited) Molecular-Level Analysis of Electrodeposition Processes Using Theoretical Calculations and Surface Enhanced Raman Microscopy
Authors: Homma Takayuki , Kunimoto Masahiro , Onabuta Yusuke , Bertz Morten , Yanagisawa Masahiro 
Published: February 2020

Electrodeposition process has been widely applied to various areas to form functional thin films and nanostructures. In order to understand the deposition process from molecular level to achieve further precise control, we employ theoretical calculation and surface enhanced Raman scattering (SERS). For the theoretical calculation to study the deposition reaction mechanism, molecular orbital and density functional theory calculations were applied to investigate the behaver of the species at the electrode surface, and various factors such as solvation effect and catalytic activity of the surface were also analysed. In addition, SERS equipped with confocal microscopy was used for in situ analysis of the reaction processes at the electrode surface. For this we applied plasmon sensors [1] to achieve very high sensitivity analysis. Furthermore multi-confocal type SERS microscopy was employed for mapping and imaging analysis. By using these techniques, various systems have been analysed and modelling of their reaction processes has been carried out.
This work was financially supported in part by “Development of Systems and Technology for Advanced Measurement and Analysis,” Japan Science and Technology Agency, and Grant-in-Aid for Scientific Research, MEXT, Japan.
[1] M. Yanagisawa, M. Saito, M. Kunimoto, T. Homma, Appl. Phys. Express, 9 , 122002 (2016).
(Invited) Multiscale Stress-Transport-Kinetics Continuum Models for Lithium-Metal Batteries-Relevance of Richard Alkire’s Electrodeposition Legacy for Next-Generation Batteries
Authors: Subramaniam Akshay , Jang Taejin , Dufek Eric J. , Subramanian Venkat R. 
Published: February 2020

Multiscale is a term commonly used/abused in the literature. First, we will quantify the meaning of ‘multiscale’ models. Richard Alkire’s selected contributions in the field of electrodeposition – Multiscale models (continuum + KMC) and finite element methods for shape changes will be reviewed. The relevance of the same for the current hot-topic in the field of lithium-metal batteries – modeling, simulating and controlling the dendrite formation in lithium-metal batteries will be discussed.
There is significant interest in using pressure as an external control to achieve proper cyclability and desirable deposition characteristics in high energy-density lithium metal anodes. We aim to provide useful predictions of cell-level variables by using a multiscale approach in which local electrochemical effects of pressure and mechanical coupling in the anode are coupled with macro homogeneous models of porous cathodes to study the effect of pressure on voltage response. Progress made in multiscale models coupling stress, transport and kinetic models at different length scales and our perspectives will be presented. Our interest lies in efficient (ideally real-time) simulation of the coupled models.

Acknowledgements

The authors would like to thank for the financial support of this work by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the DOE through the Advanced Battery Material Research (BMR) Program (Battery500 consortium) and the Clean Energy Institute (CEI) at the University of Washington and the Washington Research Foundation (WRF) for their partial monetary support during this work.