bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrolytes for Li-Ion Batteries Based on High Voltage Cathodes
Authors: Jow T. Richard , Delp Samuel A. , Allen Joshua L. , Borodin Oleg , Allen Jan L. 
Published: February 2020

The electrolyte is a critical part of today’s Li-ion batteries. The state-of-the-art Li-ion batteries, which are made of cathodes such as 4.1 V LiCoO2 and 3.4 V LiFePO4 and graphite anode, function well in the state-of-the-art electrolytes made of LiPF6 in carbonate solvent mixtures such as EC and EMC with additive such as VC. The reason for this compatibility is attributed to the facts that the cathodes are within the stability range of the electrolytes and the ability of the electrolyte for forming a solid electrolyte interphase (SEI) layer on graphite, protecting the graphite anode from reacting with the electrolytes.
When developing higher energy density Li-ion batteries based on higher voltage cathodes such as 4.7 V LiNi0.5Mn1.5O4 (LNMO) and 4.8 V LiCoPO4 (LCP), the oxidative stability of the state-of-the-art electrolytes is in question. Furthermore, the stability of the high voltage cathodes themselves is also not certain. Efforts in improving the stability of LNMO and LCP through substitutions have yielded better performing cathodes in terms of improved capacity retention and coulombic efficiency.1, 2

The search for electrolytes that work with the high voltage cathodes has been intensive. Molecular modeling to understand the oxidative stability of Li-ion electrolytes has been active.3 This paper will review our recent efforts on electrolyte development for improving the electrochemical performance of the high voltage cathodes in Li-ion batteries.
References

A. Manthiram, Phys.Chem. Lett. 2011, 2, 176-184.

J. L. Allen, T. R. Jow, J. Wolfenstine, J. Power Sources 2011, 196, 8656.

O. Borodin, W. Behl, T. R. Jow, J. Phys. Chem. C 2013, 117, 8661-8682.
BASF - Lithium Ion Battery Electrolytes
Authors: Schmidt Michael , Chesneau Frederick Francois , Garsuch Arnd , Meini Stefano , Schmitz René 
Published: February 2020

Research and development efforts of BASF are stimulated by the future energy demand of our society. Thus we investigate and evaluate energy storage systems for mobile and stationary applications.
BASF develops products for the battery industry with its knowledge and experience in chemicals and materials. Our research activities are focused on the development of new materials for improved lithium ion battery performance. Currently, we are focusing on the development of next generation cathode materials and high performance electrolyte systems.
The first part of the talk will give an overview on BASF’s growing activities in the field of lithium ion battery materials. The second part will concentrate on lithium ion battery electrolytes with a special focus on electrolyte and electrolyte additives for high voltage cathodes.
Atomic Force Microscopy Study of Ionic Liquid Structure at Carbon Interface
Authors: Black Jennifer , Feng Guang , Okatan M. Baris , Hillesheim Patrick C , Dai Sheng , Cummings Peter T , Kalinin Sergei V. , Balke Nina 
Published: February 2020

Ionic liquids are attractive electrolytes for electrochemical capacitors because of the large operational voltage windows leading to an increased energy density in these systems. The charge storage mechanism and structure of ionic liquids at the interface is still poorly understood. Atomic force microscopy (AFM) force spectroscopy is capable of probing the layered structure of ionic liquids which forms at the electrode interface. Figure 1 shows the ion density profiles from molecular dynamics for the cation (a) and anion(b) of the ionic liquid 1-ethyl-3methyl-imidazolium bis(trifluoromethanesulfonyl)imide (Emim+Tf2N-) as a function of potential and distance from a carbon surface. Molecular dynamics predicts an alternating structure of anions and cations extending several nm from the surface. A histogram of 50 force distance curves on a highly oriented pyrolytic graphite (HOPG) for the same ionic liquid is shown in Figure 1c. Distinct steps are observed during the approach of the AFM tip due to interaction with the ion layers present at the interface. By combining this technique with insights from molecular dynamics simulations the effect of applied potential on the structure of the ionic liquid within the electrical double layer is investigated and we are able to observe reconstruction of ions in response to an applied bias. This technique is also used to map the structure of the ionic liquid over the carbon surface to investigate the effect of defects such as step edges on the structure of the ionic liquid.
Figure 1: Molecular dynamics ion density profiles as a function of potential and distance from a carbon surface for the Emim+ cation (a) and Tf2N- anion (b). Histogram of 50 consecutively measured force distance curves at a single location on an HOPG surface in Emim+Tf2N- ionic liquid (c).
Electroactive Polymer Based Porous Membranes for Energy Storage Applications
Authors: Costa C. M. , Lanceros-Méndez Senentxu 
Published: February 2020

The market of portable batteries will reach $30.5 billion dollars in 2015 with an annual growth rate of 8.5% [1]. This growth is interconnected with advances of the portable electronic products (mobile-phones, computers) and with the development of new products such as e-labels, e-packaging, disposable medical testers and drug delivery patches.
Wide ranges of materials properties for cathode, anode and battery separator/electrolyte are being developments for improving characteristics and performance of the battery.
The battery separator is essential in electrochemical cells, separating the anode and cathode and controling the number and mobility of the lithium ions.
Among the materials most investigated for battery separators are the PVDF and its copolymers poly(vinylidene fluoride-co-trifluoroethylene), PVDF-TrFE, poly(vinylidene fluoride-co-hexafluoropropylene), PVDF-HFP, and poly(vinylidene fluoride-cochlorotrifluoroethylene),PVDF-CTFE [2].
These materials show strong advantages for their use as separator membranes in comparison to polyolefins due to their high dipolar moment and large dielectric constant for a polymer material, which can assist ionization of lithium salts.
In this work, PVDF and its copolymers have been processed by solvent cast technique with varying solvent evaporation temperature and the polymer/solvent ratio with the objective to tailor degree of porosity, mechanical, thermal and electrical properties.
Degree of porosity, uptake, tortuosity, degree of crystallinity and ionic conductivity of the different membranes are evaluated and their influence in lithium-ion battery performance presented and discussed.

Acknowledgments

This work is funded by FEDER funds through the “Programa Operacional Factores de Competitividade—COMPETE” and by national funds from FCT—Fundação para a Ciência e a Tecnologia, in the framework of the Strategic Project PEST-C/FIS/UI607/2011, project F-COMP-01-0124-FEDER-022716 and grant SFRH/BD/68499/2010 (C.M.C.). The authors also thank funding from Matepro –Optimizing Materials and Processes”, ref. NORTE-07-0124-FEDER-000037”, co-funded by the “Programa Operacional Regional do Norte” (ON.2 – O Novo Norte), under the “Quadro de Referência Estratégico Nacional” (QREN), through the “Fundo Europeu de Desenvolvimento Regional” (FEDER).
The authors thank Celgard LLC, Timcal, Solvay, Arkema and Clariant for kindly supplying their high quality membranes and excellent materials, respectively.

References

[1] P. R. Consulting, Advanced Batteries for Portable Power Applications, 2011.
[2] C.M. Costa, M.M. Silva, S. Lanceros-Mendez, RSC Advances, 3 (2013) 11404
Single Crystal, Cuprous Oxide Nanowire Arrays for Highly Stable Photocathodic Water Splitting
Authors: Banerjee Sriya , Wu Fei , Myung Yoon , Banerjee Parag 
Published: February 2020

Cuprous oxide (Cu2O) is a favorable material for solar water splitting because of its suitable band gap for solar energy absorption (2.2eV) and conduction and valence band edges which straddle the hydrogen and oxygen reduction potentials, respectively. Further, Cu2O is earth abundant and can be synthesized by a variety of techniques. However, Cu2O has its reduction potential within its band edges, leading to considerable photocorrosion and degradation. Thus, there is a pressing need for the fabrication of stable and efficient Cu2O photocathodes.
Here, we investigate the photoelectrochemical (PEC) properties and stability of dense (108 cm-1) single crystalline Cu2O nanowire (NW) arrays grown by a combination of thermal and carbo-thermal reduction method from pristine copper foils (Fig 1a-d). Our data shows that single crystalline Cu2O NW arrays, show good photoresponse (Fig 1e) and higher stability as compared to thin film Cu2O (Fig 1f,g).
We will present structural investigation of the Cu2O NWs using SEM, HRTEM and Raman spectroscopy (Fig. 1a-d). Photoelectrochemical activity of Cu2O NW arrays for water splitting will be reported and stability towards photocorrosion will be tested with extended and accelerated reliability tests.
A Comprehensive Electrochemical Solution to Climate Change: STEP, the Solar Thermal Electrochemical Pressure Process for the Production of Societal Staples
Authors: Licht Stuart 
Published: February 2020

The solar thermal electrochemical pressure process is capable of the production of societal staples with little or no carbon footprint, and can directly capture & convert carbon dioxide from the air that can be stored as useful graphite.In STEP the efficient formation of metals, fuels, cement, chlorine, and carbon capture is driven by solar thermal heated endothermic electrolyses of concentrated reactants occurring at voltage below that of the room temperature energy stored in the products. As one example, CO2 is reduced to either fuels, or storable carbon, at solar efficiency higher than the best photovoltaics. This is due to a synergy of efficient solar thermal absorption and electrochemical conversion at high temperature and reactant concentration. CO2-free STEP iron production, from iron ore, occurs via Fe(III) in molten carbonate. Water is efficiently split to H2 by molten hydroxide electrolysis, and chlorine, sodium and magnesium from molten chlorides. STEP cement uses a novel molten electrochemistry for the production of calcium oxide (lime from limestone).1-7

The solar electrochemical generation of societal staples and fuels decreases society's dependence on grid-based electricity. A pathway is provided for the STEP decrease of atmospheric carbon dioxide levels to pre-industrial age levels in 10 years.
Selected STEP references:
(1) S. Licht, "STEP generation of energetic molecules: A solar chemical process to end anthropogenic global warming," J. Phys. Chem., C, 2009, 113, 16283-16292.
(2) S. Licht, B. Wang, S. Ghosh, H. Ayub, D. Jiang, J. Ganley, "A New Solar Carbon Capture Process: STEP Carbon Capture," J. Phys. Chem. Lett., 2010, 1, 2363-2368, with online 2 page supplement.
(3) S. Licht, "Efficient Solar-Driven Synthesis, Carbon Capture, and Desalinization, STEP: Electrochemical Production of Fuels, Metals, Bleach," Advanced Materials, 2011, 47, 5592-5612.
(4) S. Licht, H. Wu, C. Hettige, B. Wang, J. Lau, J. Asercion, J. Stuart, " STEP Cement: solar thermal electrochemical production of CaO without CO2 emission " Chem. Comm., 2012, 48, 6019-6021, with online 20 page supplement.
(5) B. Wang, Y. Hu, H. Wu, S. Licht, "STEP Pollutant to Solar Hydrogen: Solar driven thermal electrochemical wastewater treatment with synergetic production of hydrogen," Electrochemical Science Letters,
2013, 2, H34-H36.
(6) B. Cui, S. Licht, ”Critical STEP advances for sustainable iron production,” Green Chemistry
,
2013, 15(4), 881-884, with 16 page online supplementary information
(7) S. Licht, B. Cui, B. Wang, ”STEP Carbon Capture: the barium advantage,” Journal of CO2 Utilization,
2013, 2, 58-63.
New Visible Semiconductors for Photoelectrochemical Water Splitting
Authors: Sunkara Mahendra Kumar 
Published: February 2020

New semiconductors with appropriate band gap and band edge energetics are needed for making serious advances in solar fuels research. This presentation will highlight our efforts in the search for new semiconductor materials specifically toward photoelectrochemical water splitting: (a) New alloys of GaN with antimony and (b) a generic informatics strategy for band gap prediction.
Applicability of the Ga(Sbx)N1−x

alloys for practical realization of photoelectrochemical water splitting is investigated using first-principles density functional theory incorporating the local density approximation and generalized gradient approximation plus the Hubbard U parameter formalism. Prior results with calculations revealed that a relatively small concentration of Sb impurities is sufficient to achieve a significant narrowing of the band gap, enabling absorption of visible light.1 Theoretical results predict that Ga(Sb
x
)N1−x
alloys with 2 eV band gaps straddle the potential window at moderate to low pH values, thus indicating that dilute Ga(Sb
x
)N1−x

alloys could be potential candidates for splitting water under visible light irradiation. Theoretical computations with Sb composition beyond 7% change the band gap from direct to indirect.2 Experimental synthesis is carried out using metal organic chemical vapor deposition using trimethyl gallium (TMGa) and Trimethyl Antimony (TMSb) and ammonia. Crystalline GaSbxN1-xfilms were obtained at x values ranging from 0-8%.
In addition, highlights of our recent work3on informatics-aided predictions of band gaps for several new chalco-pyrite materials will be provided.

Acknowledgements: Financial support from US Department of Energy (DE-FG02-07ER46375) and NSF (DMS1125909).

References:

R.M. Sheetz, E. Richter, A.N. Andriotis, C. Pendyala, M.K. Sunkara and M. Menon, “Visible light absorption and large band gap bowing in dilute alloys of gallium nitride with antimony”, Phys. Rev. B, 84, 075304 (2011)

S. Sunkara, V.K. Vendra, J.B. Jasinski, T. Deutsch, A.N. Andriotis, K. Rajan and M.K. Sunkara, “New Visible Light Absorbing Materials for Solar Fuels, Ga(Sbx)N1-x”, In Press, Adv. Mater. (2013).

P. Dey, J. Bible, S. Datta, S. Broderick, J. Jasinski, M.K. Sunkara, M. Menon, and K. Rajan, "Informatics aided band gap engineering for solar materials", Accepted, J. Comp. Mater. Sci., (2013).
Cold Gas Sprayed Semiconductor-Based Electrodes for the Photooxidation of Water
Authors: Herrmann-Geppert Iris , Bogdanoff Peter , Emmler Thomas , Gutzmann Henning , Gärtner Frank , Dittrich Thomas , Klassen Thomas 
Published: February 2020

Photoassisted water splitting for hydrogen generation requires the development of low cost, but highly efficient photoelectrodes. For the industrial hydrogen production with photoelectrochemical cells suitable catalysts and feasible photoelectrode preparation processes still need to be identified.
This contribution explores the potential of cold gas spraying (CGS) for the production of photoanodes employing semiconductors for the water oxidation reaction (OER). Conventional large area coating techniques usually employ wet chemical methods with subsequent calcination steps to obtain enhanced binding between the catalyst particles and the substrate. In the cold gas spraying process, particles are accelerated to high velocities by a pressurized gas. The nitrogen used as process gas is preheated and then expanded in a De Laval type nozzle. On impact with the substrate, the particles deform and break up and thus can build an efficient interface to the back contact.
For a first demonstration TiO2 aggregates delivered by EVONIK were probed for the preparation of TiO2 photoelectrodes. In photoelectrochemical experiments these cold gas sprayed TiO2 photoelectrodes showed seven times higher photocurrents in the photooxidation of water (at 1.23V(NHE)) than reference electrodes prepared by the established doctor blade technique. In systematic experiments it was observed that with increasing gas temperature in the coating process the obtained photocurrent is enhanced. The better performance can be mainly attributed to an improved bonding of the TiO2 particles to the substrate (back contact) due to their increased impact energy. Although the bulk characteristics of the particles remained unchanged incident photon to current efficiency (IPCE) and surface photovoltage measurements reveal the formation of surface-localized interband transitions at the TiO2 surface (1.2, 2 and 2.4 eV) during the CGS process. In order to study the influence of these defects on the photoreaction performance surface modification by plasma treatment is employed. For this structure-activity correlation analysis by Raman, XRD and XPS is performed.
From these initial experiments the preparation is extended to other potential metal oxides (e.g. WO3, Fe2O3 and BiVO4) for the photooxidation of water. Besides the relevant particle-substrate bonding and defect chemistry of the semiconductor layer due to the process, morphology investigation by SEM, gas sorption and 3D topography are considered for the optimization of the coating technique.
Quinone-Based Flow Battery with Increased Open Circuit Voltage
Authors: Gerhardt Michael R. , Marshak Michael P. , Huskinson Brian , Gordon Roy G. , Aziz Michael J. 
Published: February 2020

Quinone-based flow batteries exhibit rapid redox kinetics, contain no electrocatalyst and use very inexpensive redox active materials [1]. Consequently, they appear to be very attractive candidates for inexpensive, large-scale electrical energy storage. We compare the performance of several substituted quinone/hydroquinone redox couples in an aqueous flow battery. We show that various substitutional groups can alter the electrochemical properties of the quinone, which in turn affects the performance of the flow battery. One substituted quinone at the negative electrode, when combined with Br2/HBr at the positive electrode, exhibits an open circuit voltage exceeding 1.0 V and a peak galvanic power density exceeding 0.24 W/cm2when fully charged.
Fig. 1. Polarization plot (a) and galvanic power densities (b) of a substituted quinone-bromine flow battery at various states of charge (SOC). The electrodes are Toray carbon paper with no electrocatalyst. The membrane is Nafion 212. The negative side is 0.5 M substituted quinone in 1 M sulfuric acid. The positive electrode is 1.5 M hydrobromic acid, 0.25 M bromine.
Membrane and Electrode Effects in the Br2 – H2 Redox Flow Cell
Authors: Tucker Michael C , Srinivasan Venkat , Battaglia Vince , Cho Kyu Taek , Weber Adam Z. , Lin Guangyu , Chong Pau Ying , Nguyen Trung Van 
Published: February 2020

The bromine - hydrogen flow cell under development at Berkeley Lab provides high power density and stable long-term cycling. During discharge, Br2 in HBr (aq) is fed to the cathode compartment where bromine is reduced to bromide, generating the theoretical open circuit potential of 1.098 V at 25°C. On charge, H2 and Br2 are generated from HBr at the (-) and (+) electrodes, respectively. The challenges include: high vapor pressure of bromine gas; migration of water and bromine to the hydrogen anode during charging; poisoning of the anode Pt catalyst by bromine; and, formation of mixed aqueous and liquid bromine phases at high states of charge (SOC).
Peak power of 1.4W/cm2 and >90% efficiency at 0.4W/cm2 were reported previously [1]. Cycling with 3M HBr electrolyte and closed anode tank (hydrogen stored in system) yielded Coulombic efficiency above 95% and energy efficiency around 80% as shown in Figure 1. Initial capacity fade was observed over the first 20 cycles, after which the capacity was stable indicating minimal loss of bromine from the system.
Cell materials selection and architecture has a large impact on cell performance. Upon discharge, limiting current behavior arises from liquid flooding in the anode reducing gas transport, as seen in Figure 2. Printing the anode catalyst layer directly on the membrane (red line) improves the performance and limiting current compared to printing it on the GDL before cell assembly (black line). Presumably this is due to improved contact at the membrane/anode interface, resulting in lower interfacial impedance for proton transport and eliminating liquid pooling between the membrane and anode.
The performance can be significantly improved by pre-boiling the membrane-anode assembly (blue line). Boiling increases transport properties, and the improved performance can be attributed to increased proton conductivity in the membrane and anode CL. Water transport and bromine crossover are also increased, however. The crossover bromine and water must be returned to the cathode to maintain concentrations in the electrolyte solution, increasing system complexity. Bromine crossover and reduction at the anode results in self-discharge, which lowers coulombic efficiency. Boiled NR212 membrane displays a high self-discharge current of 13 mA/cm2, compared to <2mA/cm2 for the as-received membrane.
The impact of these effects on system performance and efficiency during charge-discharge cycling will be discussed.
References
[1] Cho KT, Albertus P, Battaglia V, Kojic A, Srinivasan V, and Weber AZ, Energy Technol. 2013, 1, 596 – 608.
Acknowledgements
This work was funded by Advanced Research Projects Agency-Energy (ARPA-E) of the U. S. Department of Energy under contract number DE-AC02-05CH11231 with cost share provided by Robert Bosch Corp and Award No. DE-AR0000262 to TVN Systems, Inc.
Optimization of Energy Storage System Considering Battery Degradation
Authors: KIM Sojin , Kwon Kyoon , PARK Hayan 
Published: February 2020

Energy storage system(ESS) is operated to save and release electric energy. And the battery in an ESS performs an essential function. For this purpose its capacity needs to be finely optimized for specific applications(peak shaving, frequency control, arbitrage, UPS etc).
Some papers have already showed the studies about the topic of optimization of battery capacity in an ESS, but a battery degradation factor and irregular operation event have not much been considered. Actually, ESS may experience a very irregular operational event and the decrease of battery capacity during repeated charge/discharge is a major issue to be addressed. In the ESS industry, usually several factors such as state of charge, time, temperature, and C-rate interdependently affect the decrease of battery capacity in a complicated mode. In order to install the ESS in a specific application looking for a reasonable benefit and a sufficent realiability, ESS lifetime prediction technique considering degradation of battery is highly required.
In this study, the battery capacity fading through test of dynamic stress factors was quantifized and reflected to designing of ESS battery. The goal is to make an accurate estimating methodology of ESS lifetime and benefit from its installation in specific applications.