bluuebunny/crossref_metadata_2025 huggingface dataset:
Copper Electrodeposition from a Deep Eutectic Solvent, Used for Nitrates Reduction
Authors: Teodoncio Beatriz Maldonado , Montes de Oca-Yemha Maria Guadalupe , Aldana-González Jorge , Estrada-Arce Elsa Miriam , Romero-Romo Mario Alberto , Palomar-Pardavé Manuel Eduardo
Published: February 2020

This research work studied Cu electrodeposition over a glassy carbon electrode (GC) using deep eutectic solventes (DESs) instead of conventional aqueous media to subsequently assess the electrodeposit catalytic properties during nitrates reduction. These are nitrogen’s most reduced form, typically present in residual waters from chemical industries, from human consumption and from agriculture, which represent a significant contamination problem; they are not at all easy to eliminate through conventional methods used in water treatment plants, because they can reach potable water sources provoking in humans the incidence of severe illnesses, like cancer among others. It has been shown, that catalysts based in Pd, Pt and Cu metal phases reduce the nitrate ions, where the Cu ones have been studied because of their attractive catalytic properties. There are various forms of synthesizing the Cu catalysts, where electrodeposition leads to better control of Cu nucleation and growth. Cu electrocristalization was carried out from DES to compare the influence of the medium over the nucleation and growth mechanism. The eutectic mixtures used were prepared from choline chloride as the ionic species while the hydrogen bond donnors were urea and ethylene glycol. Both the DES were prepared in a 1:2 molar ratio, taking particular care to establish the influence of the resulting liquid at the early stages of electrodeposition, which was studied from Cu (II) solutions. It was shown that its electrodeposition takes place through a separte stage during which Cu (II) reduces first to Cu (I). All media studied led to demonstrate that electrodeposition follows a nucleation and 3D diffusion controlled growth. The Cu (II) diffusion coefficient, the A (nucleation frequence) and N0 (number density of active sites) parameters were estimated from potentiostatic plots using the Heerman and Tarallo model. The nitrates reduction at different concentrations was studied via differential pulse voltammetry to determine analytical parameters, like sensibility, detection and quantification limits. The Cu-modified glassy carbon electrodes and a Cu bar served to reduce the nitrates, immersed in 100 mM NaCl supporting electrolyte at pH=1.4 set with HClO4 analytical grade, adding different KNO3 concentraciones. It was shown that in acid medium the nitrates ion can be quantified reliably.

Figure 1
Novel Pyrolyzed Carbon Processing for Advanced Microelectronic Applications
Authors: Finnegan Patrick Sean , Washburn Cody M , Dyck Christopher , Burckel D Bruce , Blecke Jill , Rector Michael N , Pfeifer Kent B. , Satches Michael R.
Published: February 2020

Sandia National Laboratories has developed an ability to fabricate multilayered, all carbon MEMS devices, complete with future mixed material signal routing. Carbon is a durable and adaptable material, suitable for many microelectronics applications and can be micromachined from blanket films, enabling a production scalable fabrication process. Silicon based MEMS systems have dominated the market for 20+ years of development, with supplemental effort leveraging the IC industry. Carbon as a standalone material and silicon with carbon offer unique combinations of material properties which complement future design space for harsh environments [Figure 1]. It can withstand high temperatures, and can also be tuned for specific performance characteristics by incorporating nanoparticles, effectively manipulating resistivity, Young’s modulus and Poisson’s ratio. Carbon is highly conductive, inexpensive, and easy to produce.

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-NA-0003525. The views expressed in the article do not necessarily represent the views of the U.S. Department of Energy or the United States Government.

Figure 1
Preparation and Polarization Behaviors of Novel Air Electrode Using Nickel-Coated Resin Particles
Authors: Okumura Takuya , Kawaguchi Kenji , Minami Kazuya , Minamiyama Hideaki , Morimitsu Masatsugu
Published: February 2020

An air secondary battery using aqueous alkaline solutions is one of the promising candidates of next-generation energy storage devices, and the bi-functional air electrode for oxygen reduction during discharge and oxygen evolution during charge is the key component for a high energy density and a good cycling performance. The air electrode typically consists of carbon material, catalyst, and PTFE, in which carbon material is light and conductive, but not highly durable for oxygen evolution, so that alternative material with a higher durability is expected. In this work, we aimed to develop a novel air electrode using core-shell structure of resin particles, of which the surface is coated with nickel alloy film by electroless deposition, since this unique material is light and conductive with a high durability for alkaline solutions and oxygen evolution. This paper presents the preparation of the air electrode and the polarization behaviors for oxygen reduction and evolution.

Nickel alloy coated resin (NCR) particles used for the air electrode were prepared by electroless deposition of nickel-phosphorus alloy on the composite resin particles comprising silica and melamine resin. The NCR particles were mixed with Bi1.87Ru2O6.903 nano-partilces as the catalyst and PTFE partilces as the water repellent agent, and the mixture was pressed onto a nickel mesh to form a sheet by roll press at 80℃. For comparison, we prepared the air electrode consisting of NCR and PTFE partilces without the catalyst. Cyclic voltammetry was performed to measure the polarization of the air electrode which faced air on one side and 6 mol/L KOH solution on the other side in a three-electrode cell.

The air electrode using NCR was successfully prepared at the weight ratio of NCR : catalyst : PTFE = 58 : 29 :13 % by roll press at 0.5 MPa. The obtained electrode showed 46% weight reduction compared to that comprising nickel alloy coated silica (NCS) particles with the catalyst and PTFE in our previous study [1]. The polarization curves of the air electrodes with and without the catalyst indicated that oxygen reduction current was quite small at the air electrode without the catalyst, while the reduction current was seen at about 0 V vs. Hg/HgO reference electrode and increased at more negative potentials, indicating that NCR particles work well as the conducting material of the air electrode. In this paper, a comparison in polarization performance between the air electrodes using NCR, NCS, and graphite powders will be presented.

Reference

[1] H. Sano, M. Morimitsu, TMS 2017, San Diego (2017).
Organic Coating Based on Nopal Cactus Mucilage, Opuntia Streptacantha, for Corrosion Inhibition
Authors: Dimas-Escorza Israel , Cotonieto- Anaya J. I. , Lopez Luis Daimir , Olguín-Coca F. J. , Lizárraga-Mendiola L. G. , Castaneda-Robles Ivan Erick
Published: February 2020

Coating development research envisions to dispense with solvent use, exploiting techniques such as water base systems, powder, UV light hardened and the substitution of heavy metals when it is possible. However, this kind of alternative formulations must consider the corrosión resistance when exposed to aggressive environments, to enable its use for industrial applications. The present work describes the formulation of an organic coating based on nopal cactus mucilage, Opuntia streptacantha, evaluated in a 5% saline solution (NaCl) corrosive environment, according to ASTM B117 for treatments in a salt spray chamber. The protection mechanism for low carbon steel was determined from electrochemical techniques such as polarization curves and electrochemical impedance spectroscopy. The obtained results include relevant information about inhibition chemistry and the diversification of agroindustrial waste, looking forward to reduce the environmental impact.
Synthesis Via Beta-Cyclodextrin of Graphene Supported Platinum Nanoparticles for Application in a Hydrogen Evolution Reaction
Authors: Abdel-Fattah Tarek M , Long Julia Madeline , Beveridge Connor , Price Brain , Osborne Justin
Published: February 2020

Carbon-based fuels are currently being consumed at an unsustainable rate.1 The increase in energy consumption of the modern world has created a demand for alternative fuel sources, and the need has never been greater.2 With mounting economic and environmental concerns, the time for the switch to a clean, reliable alternative is prime. Hydrogen gas is a popular choice due to its low greenhouse gas emissions however, pure hydrogen gas is problematic due to its high flammability. Hydrogen feedstock materials are currently being explored due to their ability to store substantial amounts of hydrogen gas in a stable and safe way.2-3 NaBH4 is a common hydrogen feedstock material because of its high percentage of hydrogen (over 10% by weight). This reaction occurs very slowly without catalytic assistance.4 Transition metal catalysts have demonstrated efficiency in the oxidation of sodium borohydride resulting in an increased release rate of hydrogen gas.4 Platinum nanoparticles have demonstrated potential as a catalyst for this reaction. Nanoparticles must be stabilized on a support system for them to achieve maximum catalytic efficiency through reduced agglomeration and by maintaining the particle shape and size distribution.2-4 Graphene and graphene oxide scaffolds may be used as a support system for platinum nanoparticles in this reaction.5 Overall, platinum nanoparticles showed the highest reaction rate of 0.0022 mol-1 sec-1 with a standard concentration of NaBH4, at a pH of 7 subjected to an increased temperature at 30°C.

References

Retnamma, R.; Novais, A.Q.; Rangel, C.M. Kinetics of hydrolysis of sodium borohydride for hydrogen production in fuel cell applications: a review. Int J Hydrogen Energy 2011, 36, 9772-9790.

Huff, C.; Long, J.; Aboulatta, A.; Heyman, A.; T. Abdel-Fattah, Silver Nanoparticle/Multi-Walled Carbon Nanotube Composite as Catalyst for Hydrogen Production. ECS J Solid State Sci Technol. 2017, 6, M115-118.

Tian, Z. Q.; Jiang, S. P.; Liang, Y. M.; Shen, P. K. Synthesis and Characterization of Platinum Catalysts on Multiwalled Carbon Nanotubes by Intermittent Microwave Irradiation for Fuel Cell Applications. The Journal of Physical Chemistry B 2006, 110(11), 5343–5350.

Pena-Alonsa R, Sicurelli A, Callone E, Carturan G, Raj R. A picoscale catalyst for hydrogen generation from NaBH4 for fuel cells. J Power Sources 2007; 165:315-23.

Kochkar, H., Aouine, Ghorbel, A.,Berhault, G. Shape-Controlled Synthesis of Silver and Palladium Nanoparticles Using β-Cyclodextrin. Journal of Physical Chemistry 2011, 115, 11364-11373.
Implication of Electrode Material Choice on Failure Characteristics of Lithium-Ion Batteries
Authors: Chandra Abhijit , Shrotriya Pranav , Sarkar Abhishek
Published: February 2020

Thermo-mechanical failure of electrode material in lithium battery system is a cause of concern for battery health and safety. With the advent of high energy storage materials and faster charging mechanisms, consideration towards the risk of failure is a substantial component in the selection of battery materials. In this work, we present a novel approach towards characterization and selection of thermally stable and mechanically favorable electrode materials using material indices. The selection process is based on a coupled thermo-mechanical multiphysics model, which solves for the deformation in the electrode during lithiation/delithiation considering the possibility of plastic deformation under high rates of charging. The thermal generation in electrode material is considered from four different mechanisms including, polarization heating due to surface charge accumulation and over potential, entropic heating due to free energy variation during lithiation/delithiation process, joule heating due to internal resistance offered by the electrode material and heat generation due to dislocation movement and phase transformation in the case of plastic deformation. Several material indices are developed for comparison of electrode materials based on their mechanical strength, fracture resistance, thermal generation and thermal diffusion characteristics. The mechanical based indices compare the electrode materials based on their capacity to generate stress during operation, resistance towards crack propagation under fatigue loading, ability to handle plastic deformation and stability under the conditions of fast charging. The thermal indices equate the thermal performance of the electrode materials based on the ability to generate less and diffuse more heat during operation. Three commonly used cathode and anode materials are compared using the above-mentioned indices and the results are verified against prior experimental data. In conclusion, these material indices provide a basis for comparison of newer high energy electrode materials against the industrially used materials, and provide crucial information regarding key material properties which affect the thermal and mechanical stability and performance of these novel materials.
(Keynote) Design of Silica-Containing Redox Nanoparticles for High-Performance Nanotherapeutics
Authors: Nagasaki Yukio
Published: February 2020

Reactive oxygen species (ROS) are known to play a variety of roles at many important events in vivo. However, overproduction of ROS causes serious adverse side effects to the living body. Numerous drugs have been developed and applied to reduce overproduced ROS. Some of them had highly efficient, but not pass clinical evaluation. Since most of these antioxidants are low molecular weight (LMW) compounds, it not only eliminates ROS related to diseases but also destroys the redox reactions necessary for the energy production of living bodies. That is, in the mitochondria in normal cells, ATP production by the electron transport chain is carried out, and a large amount of ROS is generated here, but LMW antioxidants nonspecifically get into normal cells and they erase even such important ROS. In order to improve selective antioxidant properties without damage to these normal redox reactions, we designed new polymer antioxidants. This polymer has self-assembling properties in an aqueous medium and gives nanoparticles. We abbreviate these nanoparticles as redox nanoparticles, RNPs. The nitroxide radicals covalently attached as a side chain of the hydrophobic segment in the amphiphilic block copolymer were compartmentalized into the solid core of the nanoparticles. Unlike LMW antioxidants, RNP is extremely poor in vivo toxicity, as RNPs are less likely to be taken up by healthy cells. Since RNPN has pH-sensitive disintegration properties, it disintegrates at pH decreasing tumors and sites of inflammation. It can therefore be used as pH responsive bioimaging and therapy. We have tried RNPs for the treatment of brain / kidney / myocardial ischemia reperfusions, cerebral hemorrhage, cancer chemotherapy, ulcerative colitis, Alzheimer's disease, etc., and confirmed their effectiveness. Based on polymer antioxidants, we have designed various nanoparticle devices such as antioxidant injectable gels. Among them, antioxidant nanoparticles with high adsorption capacity (siRNP) were designed encapsulation nanosilica in siRNP has proven to be useful as peritoneal dialysis and oral DDS due to its high antioxidant capacity and adsorption capacity. This paper summarizes recent applications of siRNP.
3D Printing of Smart Gels
Authors: Shiblee MD Nahin Islam , Ahmed Kumkum , Saito Azusa , Takamatsu Kyuichiro , Yoshida Kazunari , Khosla Ajit , Kawakami Masaru , Furukawa Hidemitsu
Published: February 2020

Various kind of gel materials for example tough double network hydrogels [1], shape memory hydrogels [2] and ionic gels [3] have been developed with potential in numerous sectors. The transparent, flexible and low friction properties of these gels have added different prospects in scientific and technological areas. Utilization of 3D printing in fabrication of gel materials is still in its infancy and thus hindering rapid prototyping and design freedom. In this work, we have fabricated smart gels like thermos-responsive gels and conductive gels etc. using both customized optical gel 3D printers named SWIM-ER and commercial printer named Acculas. This process of 3D printing enabled rapid and moldless fabrication of smart gels with variety of 3D design from macro to micro scale. Robust thermos-responsive Poly (dimethyl acrylamide-co-stearyl acrylate and/or Lauryl Acrylate) (PDMMAm-co-SA and/or LA)-based shape memory gels (SMGs) with tunable mechanical, thermal, swelling, and optical properties are obtained by optimizing their critical conditions during 3d printing. The superior physiochemical properties of such smart gels widen the range of applications for soft robotics, biomedicine, flexible electronics, mimicking organ structure, bioinspired lens and sensing applications.

References

Gong, J. P., Katsuyama, Y., Kurokawa, T., Osada, Y., “Double-Network Hydrogels with Extremely High Mechanical Strength,” Adv. Mater., 15, 1155-1158 (2003).

Kabir, M.H., Ahmed, K. Furukawa, H., Microelectron. Eng. 150, 43–46 (2016).

Ahmed, K., Watanabe, Y., Higashihara, T. Arafune, H. Kamijo, T., Morinaga, T. Sato, T., Makino, M. Kawakami, M., Furukawa, H. Microsyst Technol 22, 17 (2016).
(Invited) Enzymatic Preparation of Supramolecular Hydrogels by Means of Amylosic Helical Assemblies
Authors: Kadokawa Jun-ichi
Published: February 2020

Amylose, which is a helical polysaccharide and well-known as a component of starch, forms controlled assemblies, such as a double helix and inclusion complexes depending on whether guest compounds are present or not. Therefore, amylose has been employed as a functional polymeric material. However, little has been reported regarding the formation of inclusion complexes between amylose and polymeric compounds. The main difficulty in incorporating polymeric compounds into the amylose cavity is that the driving force for the binding is only caused by hydrophobic interactions. Amylose, therefore, does not have sufficient ability to include the long polymeric chains. The author has developed a new method of the polymerization system called “vine-twining polymerization” for the formation of well-defined polysaccharide supramolecules, that is, amylose–polymer inclusion complexes. The method was achieved by phosphorylase-catalyzed enzymatic polymerization of α-D-glucose 1-phosphate (G-1-P) monomer from malooligosaccharide primer to produce amylose, in the presence of hydrophobic synthetic guest polymers. The image of this polymerization system is the similar as the way that the vines of a plant grow twining around a rod. By means of this method using designed guest polymers, the author has prepared hierarchically controlled amylosic supramolecular network materials, which formed hydrogels in aqueous media.

For example, the author performed the preparation of supramolecular network hydrogels by the vine-twining polymerization using graft copolymers composed of hydrophobic graft guest polymers, such poly(γ-glutamic acid-graft-ε-caprolactone) (PGA-g-PCL). A supramolecular network hydrogel was obtained with the progress of the vine-twining polymerization, which showed a self-standing property. Macroscopic interfacial healing was achieved by the formation of inclusion complexes at interface between two hydrogel pieces through the enzymatic polymerization. A porous cryogel based on supramolecular network structure was obtained by lyophilization of a hydrogel. The XRD result of the lyophilized sample indicated the presence of inclusion complexes of amylose with the PCL graft-chains between intermolecular (PGA-g-PCL)s, which acted as supramolecular cross-linking points for the hydrogelation. Furthermore, ion gels were fabricated by soaking the hydrogels in an ionic liquid, 1-butyl-3-methylimidazolium chloride.
Friction Properties and Surface Observation By Surface Processing on High Strength Gels
Authors: Wada Masato , Yoshida Kazunari , Khosla Ajit , Furukawa Hidemitsu
Published: February 2020

We measured the friction forces and calculated the friction coefficients of non-processed and laser-processed High Strength gel surfaces. The results indicate that laser processing (finishing) has an ability to reduce the friction coefficients. The observation of gel surfaces suggests that the cause of friction reduction is change in roughness of gel surfaces due to laser processing. This finding is expected to lead us to further understanding of physicochemical properties of hydrogels.

We showed the low-friction processing technique. We demonstrated that the laser processing has an ability to reduce the friction of hydrogel surfaces. The results of microscopic observations suggest that the cause of friction reduction is decrease in apparent contact area between hydrogel surface and glass ball. This technique may lead us to next step in the fields of physics, physical chemistry, and medical applications.
Thermo-Responsive Behavior of Polymer Solutions Coated with Phospholipids
Authors: Yoshida Kazunari , Horii Keitaro , Saito Azusa , Takashima Akito , Nishio Izumi
Published: February 2020

Various kinds of cell model systems have been utilized for fundamental studies on physical properties of cells. Water-in-Oil (W/O) droplet system coated with phospholipids is one of the beneficial simple model systems of living cells. For instance, a biomimetic phase-separated membrane was constructed in the W/O systems with phospholipid mixture (Hamada et al., J. Phys. Chem. Lett., 2010) since phase separation in lipid membrane system corresponds to the separation between lipid raft domains and other soft domains in the living cell membranes.

Phase transition of a polymer has been studied for many years, such as coil-globule transition (Nishio et al., Nature, 1979), and helix-coil transition (Tanaka et al., J. Chem. Phys., 1973). In addition to the phase transition of polymers, phase separation in a binary polymer solution was also reported (Yanagisawa et al., J. Mol. Liq., 2014). However, cell-sized confinement effects on polymer solutions have been poorly confirmed.

To clarify the cell-sized confinement effects on polymer solutions, we previously observed the dynamic behavior of polymer droplets (Yoshida et al., Polymers, 2017). The previous study revealed that droplet size influences the start time of phase separation in the case of temperature change from 10 to 65 degrees Celsius.

In this study, we observed the dynamic behavior of hydroxypropyl cellulose (HPC) solution droplets in response to temperature change from 10 to 65 degrees Celsius using a fluorescence microscope. The droplets were coated with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) or 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE). As a control, we observed non-coated water droplets. DPPC and DPPE are widely used for studies on model cell membranes. Using time-lapse images, we confirmed the water/HPC distribution using a spatial autocorrelation function. The results revealed that water-rich region appeared in the case of lipid coated droplets with increase in temperature while such phenomenon was not observed in the case of non-coated droplets.
(Invited) Economical and Safer Approach to Biodegradable Biocompatible Hydrogel
Authors: Meabe Leire , Takahashi Junko , Zivic Nicolas , Sardon Haritz , Mecerreyes David , Fukushima Kazuki
Published: February 2020

The use of polycarbonates in the biomedical application has been largely studied, owing to appropriate biodegradation reaction, without producing any by-products [1, 2]. Generally, the synthesis of the polycarbonates is via ring opening polymerization, which requires several steps and high purity of the reagents.

Step growth polymerization can be an easy method to design polycarbonates with molar masses around 20,000 g mol-1 [3]. The protocol of organocatalytic polycondensation consists of a two-step reaction, which involves an initial condensation and the subsequent chain propagation based on transesterification. The reaction will be catalyzed by organic based catalyst, N,N’-dimethyl-4-aminopyridine (DMAP). From Scheme 1, the possibility of tuning the polycarbonate structure can be deduced; the diol is a key reagent of designing the final homopolymer or copolymer structure. This methodology gives us an opportunity to obtain linear or cross-linked polymer. In our work, we have incorporated a mono-ether functionality for biocompatibility as well as a double bond for formation of a cross-linked network.

Scheme 1. The polycondensation approach for new polycarbonate-based biocompatible gels.

[1] K. Fukushima, Poly(trimethylene carbonate)-based polymers engineered for biodegradable functional biomaterials, Biomaterials Science, 4 (2016) 9-24.

[2] K. Fukushima, Y. Inoue, Y. Haga, T. Ota, K. Honda, C. Sato, M. Tanaka, Monoether-Tagged Biodegradable Polycarbonate Preventing Platelet Adhesion and Demonstrating Vascular Cell Adhesion: A Promising Material for Resorbable Vascular Grafts and Stents, Biomacromolecules, 18 (2017) 3834-3843.

[3] L. Meabe, N. Lago, L. Rubatat, C. Li, A.J. Müller, H. Sardon, M. Armand, D. Mecerreyes, Polycondensation as a Versatile Synthetic Route to Aliphatic Polycarbonates for Solid Polymer Electrolytes, Electrochimica Acta, 237 (2017) 259-266.

Figure 1
(Invited) The P2 Sodium Layered Oxides in Na Ion-Batteries
Authors: Delmas Claude , Carlier Dany , Guignard Marie , Yoshida Jun
Published: February 2020

The development of very large scale renewable energy systems requires optimizing the lifetime, the price and the material availability. From these points of view, sodium based batteries have to be investigated. Our research group studied layered oxides as positive electrode for 30 years. Now a special focus is devoted on P2-type layered phases.

One of the main interests of this structure is the existence of an ion conduction plane made of face sharing trigonal prims which exhibits a high ionic diffusivity thanks to the existence of a large bottleneck (oxygen rectangle) for sodium diffusion. This structure is able to accommodate a lot of transition metal cations, allowing the optimization of the properties by cationic substitution.

Studies was performed on the P2- Nax(Mn,Co)O2, Nax(Mn,Fe)O2, Nax(Mn,Fe,Co)O2 and Nax(Mn,Fe,Ni)O2 systems with various amounts of transition metal ions. All materials crystallize in the hexagonal system (P63/mmc space group). The structure is made of MO2 slabs built of corner sharing MO6 octahedra. The sodium ions are in trigonal prismatic sites. Half of them share edges (Nae) with the MO6 octahedra while the other one share faces (Naf). As the two types of prisms share a common face, they cannot be occupied simultaneously at the atomic scale. The sodium distribution depends of the cationic charge distribution and of the sodium amount is order to minimize the Na+-Na+ and Na+-Mn+ electrostatic repulsions. This lead to a large number of ordered Na+ distribution as it was shown in the case of the NaxCoO2 systems. In materials with several transition metal cations, their statically distribution in the slabs prevent generally from Na+ ordering.

In all systems, the P2 type packing is preserved in the 0.3 < x < 1 range. The fully intercalated phase is difficult to be obtained due to the very low ionic conductivity when the amount of vacancies is very small. For these compositions, only the Naf prisms are occupied. The specific capacity is in the 130-170 mAh.g-1 depending on the voltage range.

For large deintercalation amounts (x < 0.3) a large polarization occurs in discharge. The GITT experiment shows that this “polarization” is not kinetics. The in-situ XRD during battery cycling from the Na0.7(Mn0.5Fe0.3Ni0.2)O2 phase shows the existence at high voltage of two phases with different interslab distances. The change in the shape of the diffraction line profiles is characteristic of the continuous formation of stacking faults.

For manganese based materials, structural distortions (Jahn-Teller effect) occurs at the end of discharge. Even if these distortions are fully reversible, they have a very bad effect on the cycling behavior.

In the intermediate composition range the reversibility is very good. Therefore, these materials can be interesting for practical applications in stationary batteries due to their low price and the availability of the raw materials.
Analysis of Oxide Film on Aluminum Electrode in Ionic Liquid Based Aluminum-Air Battery
Authors: Mohammad Abdul , Gong Jue , Hosmane Narayan S , Xu Tao , Cho Kyu Taek
Published: February 2020

In this research, aluminum air battery system was revisited to investigate key issues which have challenged its full application as a rechargeable battery. The Al-air battery had received intense attention once due to the excellent benefits such as low cost and high energy density, but due to the challenging issues such as hydrogen evolution, and inactive oxide film formed on the Al surface, it could not be fully applied. Recently, ionic liquid which is a salt in liquid form at room temperature started to be applied in the battery system to overcome the issues in aqueous electrolyte [1,2], but the inactive oxide film on Al surface is still dominant in decreasing cell performance and detailed research to understand how to control the oxide film was not conducted. In this study, 1-Ethyl 3-Methyl Imidazolium Chloride ([EmIm]Cl) and Aluminum Chloride (AlCl3) was applied in the Al-air battery, and its effect on oxide film on the surface aluminum electrode was analyzed through cell-base test, and SEM image analysis.

It was found that the inert oxide film on aluminum, which is one of the most challenging issues, could be controlled and removed by using of proper ratio of [EmIm]Cl and AlCl3, and the growth/breakdown mechanism of the oxide film was theoretically considered. This research results are expected to suggest a new direction to control the surface of aluminum electrode to make it the most promising system.

References

[1] D. Gelman, B. Shvartsev, Y. Ein-Eli, Journal of Materials Chemistry A, 2 (2014) 20237-20242.

[2] R. Revel, T. Audichon, S. Gonzalez, J. Power Sources, 272 (2014) 415-421.
(Invited) In-Operando Neutron Scattering Studies of Interfacial Electrolyte Chemistry
Authors: Bridges Craig A. , Jafta Charl J , Sun Xiao-Guang , Veith Gabriel M. , Jensen Grethe V. , Heller William , Cuneo Matt J. , Mahurin Shannon , Paranthaman Mariappan Parans , Dai Sheng
Published: February 2020

The electrode-electrolyte interface plays a critical role in the performance of electrochemical energy storage systems. To understand the complex processes occurring at the interface of Li-ion or Na-ion batteries, and how these relate to processes occurring in the electrodes, multiple techniques are required. In addition to methods such as X-ray diffraction, Raman spectroscopy, and transmission electron microscopy that are available in the laboratory, specialized in-operando experiments at major facilities are being developed that provide unique information on the dynamic evolution in rechargeable batteries, electrochemical supercapacitors, and more. Here we discuss the use of small angle neutron scattering to investigate changes in solid electrolyte interphase (SEI) formation, pore filling, and electrode microstructure during cycling. This work relies upon the use of high surface area electrodes to provide sufficient signal for neutron scattering studies, which traditionally rely upon gram scale quantities of material. Additional ex-situ data may be collected using methods such as X-ray photoelectron spectroscopy (XPS) to help constrain the interpretation of the data. Up to now, several electrochemical systems have been investigated, in particular including carbonate electrolytes with LiPF6 or NaPF6 salts, and several ionic liquid-based electrolytes and salts. This talk will present work on various electrolyte systems, demonstrating the high level of detail provided, and illustrating the process of interpreting the scattering curves. Recent work on the electrolytes containing TFSI- and FSI- salts will be highlighted, along with improved understanding of concentrated electrolyte systems.

Acknowledgement: Research was sponsored by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division. Research at Spallation Neutron Source user facility was sponsored by the Division of Scientific User Facilities, Office of Basic Energy Sciences, US Department of Energy, under contract DE-AC05-00OR22725 with UT-Battelle, LLC.
A Microporous Gel Polymer Electrolyte for Sodium Batteries
Authors: Kalami Somayyeh , Khani Hadi , Goodenough John Bannister
Published: February 2020

Room-temperature sodium batteries have the potential to meet the growing worldwide demand for electrical energy storage, thanks to the widespread availability and low cost of sodium. Compared with traditional liquid electrolytes, gel polymer electrolytes (GPEs) offer higher safety and adaptability to be designed as ﬂexible energy storage devices without sacrifice of conductivity. In this work, we have successfully synthesized furan-based hypercrosslinked microporous polymers (Fu-HCPs) by using a solvothermal method. The prepared Fu-HCPs demonstrate a high surface area ≈ 500 m2 g‒1 with a pore-size distribution of 5−15 Å. A novel porous membrane consisting of a double polymer network of microporous Fu-HCPs and macroporous poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) is fabricated via a phase-inversion technique. The corresponding polymer electrolyte is prepared by immersing the porous membrane into a sodium liquid electrolyte. The macroporous and microporous nature of the prepared polymer membrane allows for an electrolyte uptake up to 200 wt. %. The polymer electrolyte saturated with sodium liquid electrolyte exhibits high conductivities (e.g., > 10‒3 S cm−1 at 25 °C) with great electrochemical (up to 4.2 V vs Na) and mechanical stability. If the microporous polymer electrolyte is applied in a full-cell sodium-ion battery with metallic sodium as an anode and Na3V2(PO4)3 as a cathode, the cycling performance and coulombic efficiency are significantly improved relative to the cell with liquid electrolyte. The results suggest that the microporous/macroporous furan-based polymer host with immobilized-liquid electrolyte inhibit sodium dendrite growth and allow the use of a metallic sodium anode for large-scale applications.
All Coconut Sprout Sodium Ion Hybrid Capacitor
Authors: Surendran Vishnu , Suviresh Arya Raveendran , Vineesh Thazhe Veettil , Babu Binson , Shaijumon Manikoth M
Published: February 2020

Electrochemical Energy storage systems play a vital role in many applications like electronics, automotive, aerospace, smart electric grids etc. There are mainly two types of energy storage systems known as batteries and supercapacitors. The first one offers high energy density, and the later one is well known for its power density. Hybrid ion capacitor (HIC) is a new class of energy storage device, a combination of battery and supercapacitor1. Commonly anode part in HIC is taken from a battery, and the cathode part will be from a capacitor and in principle, the duo offers intermediate energy and power density in comparison with batteries and supercapacitors2
3. Sodium based hybrid capacitors are extensively explored today due to large abundance and low cost of sodium4. Here in we report for the first-time, fabrication of a hybrid sodium ion capacitor, in which the cathode, anode and separator are derived from a single precursor called coconut sprout (CS). Graphene-like carbon derived from CS, employed as an intercalating anode, provides a specific capacity of 181.09 mAhg-
1. High surface area (BET surface area of 2000 m2g-1) ion adsorption cathode part obtained by KOH activation of CS delivers a capacity of 90.15 mAhg-
1. Combination of CS derived anode, cathode and separator give rise to a capacitor works in a potential window of 1.5 -4.0V. The all sprout capacitor could deliver an energy density of 88.12 Whkg-1 at power density 273.26 Wkg-1 and energy density of 25.07 Whkg-1 at power density 7078 Wkg-1. This green, all sprout hybrid capacitor retained 65% of its initial capacity after 5000 cycles, while cycled at a current density of 1Ag-1. The spongy sprout separator showed excellent chemical and mechanical stability even after 10000 cycles of charge and discharge. Though the performance is not outstanding, low cost single precursor, facile synthesis route, minimal environmental impact of the device makes it a promising candidate among eco-friendly electrochemical systems.

Reference

(1) Amatucci, G. G.; Badway, F.; Du Pasquier, A.; Zheng, T. An Asymmetric Hybrid Nonaqueous Energy Storage Cell. J. Electrochem. Soc.
2001, 148 (8), A930.

(2) Ding, J.; Wang, H.; Li, Z.; Cui, K.; Karpuzov, D.; Tan, X.; Kohandehghan, A.; Mitlin, D. Peanut Shell Hybrid Sodium Ion Capacitor with Extreme Energy-Power Rivals Lithium Ion Capacitors. Energy Environ. Sci.
2015, 8 (3), 941–955.

(3) Sivakkumar, S. R.; Pandolfo, A. G. Evaluation of Lithium-Ion Capacitors Assembled with Pre-Lithiated Graphite Anode and Activated Carbon Cathode. Electrochim. Acta
2012, 65, 280–287.

(4) Ding, J.; Hu, W.; Paek, E.; Mitlin, D. Review of Hybrid Ion Capacitors : From Aqueous to Lithium to Sodium. Chem. Rev.
2018, 118, 6457–6498.
Fundamental Investigation of AlCl3-Amide Electrolyte for Application in Aluminum Ion Battery
Authors: Malik Monu , Ng Kok Long , Azimi Gisele
Published: February 2020

In recent years, aluminum-based batteries have received increasing attention because of the high abundance and high volumetric and gravimetric capacity of aluminum and the growing need for secondary batteries. Aluminum and its alloys are extensively utilized for surface coating because of their excellent corrosion resistance, high electric conductivity, and low density. Thus, the study of electrodeposition of aluminum and its alloys has received increasing attention, especially at room temperature. The electrodeposition of aluminum is only possible in organic solvents or in ionic liquids because of its high reactivity and high negative reduction potential (–1.67 V vs. SHE). The application of organic solvents for electrodeposition of aluminum is also limited because of their narrow electrochemical window, very low solubility of Al salts, and low thermal stability. Ionic liquids have the ability to dissolve a large variety of compounds because of their strong electrostatic interactions and the ability to remain liquid at room temperature as well as good thermal stability, low volatility, and low toxicity. A new class of ionic liquids, knowns as ionic liquid analogs (ILAs) or deep eutectic solvents (DESs) have received increasing attention as an alternative to traditional ionic liquids because of their low price, higher solvability of metal chlorides and better largescale viability. The ILAs are derived from a mixture of AlCl3 and an oxygen donor amide (urea or acetamide) ligand. Despite their wide employment in research especially for new Al-ion batteries, there is lack of fundamental data on their structure/property relationship, including speciation of the ionic moieties at different molar compositions. In the present study, physicochemical properties of a room temperature ILA composed of AlCl3 and urea is investigated by varying the molar ratio of AlCl3/urea from 1.0 to 1.5. The effect of temperature on the electrodeposition of aluminum and its structure is studied using cyclic voltammetry and scanning electron microscopy. Different additives are utilized to improve the ionic conductivity and to reduce the viscosity of AlCl3/urea electrolyte and their effect is investigated. The results indicate that the addition of these additives improves the electrolyte properties, but reduces the voltage stability window of the electrolyte. Future work is underway to further investigate the effect of temperature on dynamic equilibrium of various ionic species present in the electrolyte to improve the properties of AlCl3/urea electrolyte.
Cell Optimisation of Supercapacitors through the Use of a Quasi-Reference Electrode and Potentiostatic Analysis
Authors: Le Fevre Lewis
Published: February 2020

In this study, the authors demonstrate a new potentiostatic aging method for the electrochemical stable potential window (ESPW) of supercapacitors and thus the calculation of the optimal mass ratio for electrode-electrolyte pairings. For this purpose a novel quasi-reference electrode (QRE) was incorporated within CR2032 coin cell containment enabling three electrode potentiostatic aging measurements to be performed using organic electrolytes whilst outside of a glovebox. Monitoring of the final current during potentiostatic aging was used to determine the ESPW of each electrode. Calculation of the voltage optimised mass ratio for activated carbon electrodes in 1 M TEABF4 ACN and PC electrolytes was achieved through attained knowledge of the ESPW and associated capacitance values[1]. The validity of the technique and use of the QRE is verified by full cell potentiostatic aging experiments on mass balanced and mass symmetric supercapacitors[2]. For both electrolytes the operating voltage and cycle lifetime of the device was improved significantly.

References

[1] D. Weingarth, H. Noh, A. Foelske-Schmitz, A. Wokaun, R. Kötz, A reliable determination method of stability limits for electrochemical double layer capacitors, Electrochim. Acta. 103 (2013) 119–124.

[2] S. Vaquero, J. Palma, M. Anderson, R. Marcilla, Mass-balancing of electrodes as a strategy to widen the operating voltage window of carbon/carbon supercapacitors in neutral aqueous electrolytes, Int J Electrochem Sci. 8 (2013) 10293–10307.
Performance of Li-Ion Batteries: Contribution of Electronic and Ionic Factors
Authors: Jaegermann Wolfram , Hausbrand René
Published: February 2020

Different combinations of cathode and anode materials have been investigated for improving the energy content of Li-ion battery materials. One of the dominant factors of performance is related to the achieved battery voltage depending on the charging state of the battery. The voltage difference of the electrochemical cell is given by the change in the Gibbs energy for the exchange of Li which will again will depend on the exchange of electrons and ions between the two phases. A systematic experimental study on the relative influence of both contributions on the measurable battery voltage have not been performed yet. Therefore we will present in this contributions surface science studies of well-defined thin film electrodes which allows to compare changes in electronic structure and related electronic surface potentials with voltage measurements. In addition, we will present first experiments on the direct measurements of the ionic work function.

A number of different thin film cathode materials with different composition of the layered oxides and olivine structural family have been prepared in recent years mostly by sputter deposition inside an integrated UHV system. Subsequently, the electronic structure and surface potentials as e. g. the electronic work function and the changes induced with charging have been determined by applying photoelectron spectroscopy. The experiments allow to relate energetic changes in the Fermi level positions to the measured battery voltage and thus deduce the relative contribution of the different electronic chemical potential to the battery voltage. Based on our data we conclude that the major contribution to the battery voltage is related to electronic work function variations of the different electrode materials.

In addition, we have performed first experiments by experimentally determining the electronic and ionic work function of electrode materials. Such experiments allow to directly determine the chemical potential of the Li atom as given by the electronic and ionic contribution in relation to the vacuum level. With a Born-Haber cycle we can show that the experimentally determined values are in reasonable correspondence to the battery voltage.

Summarizing our results we conclude that the performance of Li-ion batteries depend on the relative changes of bonding contributions for electrons and ions within the used electrodes with electrons providing the larger part to the battery voltage. Measured variations in performance must be related to deviations of the rigid band behavior of the electrode materials and to surface effects occurring in the given battery set-up.
Structure of Confined Ionic Liquids in Graphitic Nanopores from Ab-Initio Molecular Dynamics Simulations
Authors: Pham Tuan Anh , Coulthard Riley , Zobel Mirijam , Buchsbaum Steven , Plata Desirée , Wood Brandon C. , Fornasiero Francesco , Meshot Eric
Published: February 2020

Room temperature ionic liquids (ILs) have recently emerged as highly promising electrolytes for a wide range of emerging energy technologies, including next-generation supercapacitors and ion-batteries, due to their high thermal stability, ionic conductivity and wide electrochemical windows. In this presentation, we combine first-principles simulations and synchrotron X-ray characterization experiments to unravel the structural properties of several imidazolium-based ILs in the bulk and at the graphitic interface, which play an important role in determining the performance of carbon-based supercapacitors. In particular, we utilize extensive ab initio molecular dynamics simulations to probe the local density distribution and medium-range order of bulk ILs, which can be directly compared and validated by X-ray scattering measurements. Having established this cross-validation, we then compare and contrast via simulation the structural, chemical and electronic properties of the ILs in the bulk and under confinement in sub-2-nm carbon slit nanopores constructed of graphene layers, which serve as model systems for understanding confinement effects in porous graphitic carbon. Our integrated theoretical and experimental approach relates these structural and chemical signatures with the intrinsic cation-anion interactions, by considering ILs with anions having significant differences in the molecular geometry, chemical composition, and charge distribution.

This work was supported by the U.S. Department of Energy at the Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.