bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Thin Film Platinum Microelectrode Granularity on Corrosion under Electrical Stimulation
Authors: Huynh Nha Uyen , Yamada Naoya , Furukawa Hidemitsu , Youssef George , Khosla Ajit , Kassegne Sam 
Published: February 2020

One of the fundamental investigations on neural interfaces for stimulation of damaged and innervated areas of the brain is focused on microelectrode arrays (MEAs). Most notably are micromachined devices of platinum electrodes insulated between polyimide, a flexible and patternable polymer.(1) Electrochemical impedance and cyclic voltammetry (CV) testings have shown that metal electrodes degrade and delaminate after only 2500 cycles whereas glassy carbon electrodes are robust enough to withstand 250,000 cycles. (2) Atomic force microscopy (AFM) images, as shown in figures 1(a) and 1(b), were obtained to compare the two types of electrodes and analysis has shown that glassy carbon electrodes have a much smoother surface topography than that of platinum electrodes. Other studies have confirmed that increased surface roughness decreases circuit yield. (3) We submit that if the metal deposition process is optimized to produce a less granular surface of the platinum electrodes, then the electrochemical performance of these MEAs should improve. In order to test this concept, devices will be fabricated under four different sputtering conditions where two parameters will be modified: the vacuum pressure and the distance between the target and substrate. The control MEAs will be fabricated at a pressure of 0.01 mbar (~7.5 mTorr) and a distance of ~10 cm. The next two sets of devices will have the same distance as the control but the pressure will be reduced by 25% and 50%. For the last condition the vacuum will be kept at 0.01 mbar and the distance will decrease to 5 cm. After which the surface morphology of the different platinum films will be studied using AFM and the circuit resistance will be tested electrochemically in a three electrode cell.
References:
1. Kassegne, S., Vomero, M., Gavuglio, R., Hirabayashi, M., Özyilmaz, E., Nguyen, S., Rodriguez, J., Özyilmaz, E., van Niekerk, P., Khosla, A., “Electrical Impedance, Electrochemistry, Mechanical Stiffness, and Hardness Tunability in Glassy Carbon
MEMS mECoG Electrodes”, J. of Microelectronics Engineering, Volume 133, Pages 36–44, 2015.
2. Vomero, M., Goshi, R., Dryg, I., Maxfield, T., Castagnola, E., Maggiolini, E., Ciarpella, F., Ordonex, J., Gueli, C., “

Glassy Carbon Based Microelectrode Array Technology for

Use in Long-Term Neural Recording and Stimulation with Superior Electrical and Electrochemical Properties”, (in process), 2015.
3. Logeeswaran, V., Chan, M., Bayam, Y. , Saif Islam, M., Horsley, D., Li, X., Wu, W., Wang, S., and Williams, R., “Ultra-smooth Metal Surfaces Generated by Pressure-Induced Surface Deformation

Figure 1
All Polymeric Electrochemical Biochip Array of Patterned Gold on Silver Inkjet Printed Polyimide
Authors: Pandey Richa , Beggiato Matteo , Sverdlov Yelena , Inberg Alexandra , Demarchi Danilo , Shacham-Diamand Yosi 
Published: February 2020

Direct writing of patterned functional electronic materials provides a new path to low cost and high throughput fabrication technology for producing integrated flexible circuits. However, it is equally important to assimilate printing technologies with solution based deposition steps in the same environment to attain a continuous and useful manufacturing process[1]. Direct patterning by inkjet printer have advantages of being low capitalization and equipment cost, high material efficiency (less than 5% of material gets wasted) and elimination of processes like photolithography[2]. Nevertheless, printed materials are characterized today by poor electrochemical performance due to i) residues of the ink binding materials on the surface of the printed circuits; ii) texture and morphologies (i.e. roughness, porosity); iii) surface impurities such as oxides. Therefore, currently, ink-jet printed electrodes have inferior biosensing properties compared to common negative printed electrodes where the metal is deposited by physical, chemical or electrochemical methods. A very realistic and simple approach to solve this issue is solution based deposition of noble catalytic metals on printed seed layer. This two-step process provides a relatively pure noble metallic high quality surface with good electrochemical properties for biosensing application. Moreover, this process is compatible with most solid and flexible substrates and fabrication processes.
A simple and efficient method has been developed to fabricate flexible, patterned gold (Au) biochip array. Micro-patterns of silver (Ag) ink were printed and dried on polyimide substrates. These micro patterns served as the activating seed layer for electrochemical Au deposition. Au deposition was carried out on Ag ink printed microchip array for various intervals of time to determine desired thickness. The thickness and conductivity measurements were performed. To investigate bio-electrochemical properties of the Au deposited chips, electrochemical impedance spectroscopy and cyclic voltammetry will be applied. The biosensing capabilities will be studied by the chronoamperometric method for different enzyme concentration.

Keywords: Inkjet printing, bio-electrochemical , Biochip array, Direct patterning.
Effect of Interdigitated Flow Field Geometry on Redox Flow Cell Performance
Authors: Gerhardt Michael R. , Wong Andrew A. , Aziz Michael J. 
Published: February 2020

A large fraction of the cost of a flow battery installation comes from the high cost of separators and bipolar plates1. Optimizing the use of active area in flow batteries by maximizing power density allows cell stack engineers to reduce the amount of stack materials required. The design of flow fields has a significant impact on cell performance, including peak galvanic power density2,3. In this work, we present an experimental and computational study of interdigitated flow fields with varying dimensions. We demonstrate reduction of resistive and mass transport overpotential losses by altering the interdigitated flow field dimensions to reduce zones of mid-channel stagnant flow within the porous electrode. A two-dimensional model of an interdigitated flow field, coupling fluid dynamics and electrochemistry, is used to guide optimization of the channel, land, and electrode dimensions in the flow field.
To study the influence of mass transport on performance, a flow cell is assembled with an unstructured, flow-through porous electrode, with a flat plate replacing the interdigitated flow field. Even with this simplified flow field, discrepancies persist between observed experimental results and predictions from porous electrode theory. We report our progress toward understanding and resolving these discrepancies.
1. V. Viswanathan et al., J. Power Sources, 247, 1040–1051 (2014)
2. M. L. Perry, R. M. Darling, and R. Zaffou, ECS Trans., 53, 7–16 (2013)
3. R. M. Darling and M. L. Perry, J. Electrochem. Soc., 161, A1381–A1387 (2014)

Figure 1. Experimental results and computational predictions of overvoltages from a symmetric potassium ferrocyanide/ferricyanide flow cell using one of four different flow fields. The cell consists of one sheet of SGL 39-AA on each side of a Nafion 212 membrane. The active area of each flow field is 5 cm2.

Figure 1
Electrode Materials for the All Vanadium Redox Flow Battery Using Mixed Acid Electrolyte
Authors: Li Jialang , Fofana Daouda , Li Xiaoan , El Sawy Ehab , Birss Viola , Shakeri Hosseinabad Fatemeh , Roberts Edward P.L. 
Published: February 2020

Operation of vanadium redox flow batteries at low (below 5◦C) and high (above 40◦C) temperatures presents a significant challenge for commercialization due to issues with the solubility of vanadium under these conditions. One strategy that has been developed is the use of a mixed sulfuric and hydrochloric chloride acid electrolyte to stabilize the vanadium species. In this study, the electrochemical characteristics of the mixed acid system was explored using cyclic voltammetry at low and high temperature, with a range of electrode materials, including carbon paper, graphite felt and nanoporous carbon scaffold (NCS). Scanning electron microscopy (SEM) was used to characterize the morphology of the electrodes materials. The results show that the mixed acid system stabilized the vanadium redox system and enable operation at higher concentrations, leading to significant improvement in electrochemical characteristics at low and high temperature. Also, NCS electrode materials were found to have higher activity than graphite paper and graphite felt for the vanadium redox systems in the mixed acid electrolyte.
Performance of a Non-Aqueous Flow Battery System with a Mushroom-Derived Electrolyte
Authors: Agar Ertan , Cappillino Patrick J , Nourani Mahnaz , Huang Haobo , Howland Rachael 
Published: February 2020

Recently, a significant emphasis has been placed on non-aqueous electrolytes for use in redox flow batteries due to their wider electrochemical potential windows, offering higher energy and power densities. To date, several non-aqueous electrolytes using organic molecules [1-2] and metal-ligand complexes [3] have been evaluated for use as electrolytes in non-aqueous redox flow battery (NRFB) systems. With these efforts, substantial performance enhancements, including a several-fold increase in energy density and improved operating temperature range, are possible compared to state-of-the- art vanadium/sulfuric acid flow batteries; however, NRFB progress has been hampered by poor electrolyte stability [4]. Thus far, development has been limited to systems with short cycle-life that exhibit capacity-fade and low current density. This underscores a key challenge currently limiting the advancement of these technologies – the stability.
We employ a bio-inspired approach to address the problem of redox-couple instability that impedes commercialization of NRFB. Our strategy of molecular design is based on naturally occurring chelating molecules that have evolved to bind metal ions extraordinarily tightly and with high-specificity. With this approach we have targeted Amavadin, a vanadium compound found in mushrooms of the Amanita genus. This molecule, and its analog, calcium vanadium(iv)bis-hydroxyiminodiacetate (CVBH) (Figure 1 inset) are among the most stable vanadium chelates ever elucidated. Initial, static-cell investigations have demonstrated that CVBH is stable to exhaustive, deep redox cycling (Figure 1), making it an excellent candidate for implementation in an NRFB system.
In this presentation we will demonstrate the performance of such an NRFB system, using this mushroom-based (CVBH) electrolyte. Results include battery cycling as well as capacity fade and efficiency analyses. The results of these analyses with respect to various operating conditions and flow cell components will also be reported.

References:

[1] Milshtein, J. D., Kaur, A. P., Casselman, M. D., Kowalski, J. A., Modekrutti, S., Zhang, P. L., Harsha Attanayake, N., Elliott, C. F., Parkin, S. R., Risko, C., Brushett, F. R., Odom, S. A. Energy Environ. Sci. 2016, 9 (11), 3531-3541.
[2] Wei, X., Xu, W., Vijayakumar, M., Cosimbescu, L., Liu, T., Sprenkle, V., Wang, W. Adv. Mater. 2014, 26 (45), 7649-7653.
[3] Suttil, J. A., Kucharyson, J. F., Escalante-Garcia, I. L., Cabrera, P. J., James, B. R., Savinell, R. F., Sanford, M. S., Thompson, L. T. J. Mater. Chem. A 2015, 3 (15), 7929-7938.
[4] Carino, E. V., Staszak-Jirkovsky, J., Assary, R. S., Curtiss, L. A., Markovic, N. M., Brushett, F. R. Chem. Mater. 2016, 28 (8), 2529-2539.

Figure 1
Modeling Slurry Electrodes for Redox Flow Batteries Using Kinetic Monte Carlo
Authors: Franco Alejandro A. , Shukla Garima , del Olmo Diaz Diego , Thangavel Vigneshwaran 
Published: February 2020

A new technological avenue, that allows utilization of conventional rechargeable battery material at grid scale, has opened up with the development of slurry redox flow batteries (SRFBs) [1]. These can offer volumetric capacity of up to 5-20 times greater than conventional redox flow batteries based on aqueous solutions [1]. However optimization and commercialization of SRFBs requires better understanding of suspension stability, non-Newtonian fluid flow behavior, electrochemical cycling phenomena, and consequent particle dynamics of the solid material in suspension.
In this work we present a multiphysics mesoscopic modeling tool resolved using an kinetic Monte Carlo algorithm [2,3] in three dimensions. This model simulates the phenomena which take place during the discharge of a SRFB in static mode with a silicon-carbon based slurry in organic electrolyte [4]. It captures the dynamics of electronic percolation networks of carbon particles created during Brownian motion. These percolation networks form electron conduction pathways for silicon particles to discharge and eventually undergo volume expansion [Fig.1]. Results are discussed in contrast to in-house experimental data [4]. Our model offers a first look into the complex interplay of intrinsic parameters that need to be understood to achieve optimization based on factors like carbon volume fractions and C-rates [5].
Fig. 1. Snapshot of the channel during galvanostatic discharge slurry containing carbon (in red) and silicon particles (in blue). When silicon is in contact with carbon percolation networks (in yellow), it can discharge. The channel thickness is 1.5 μm and the area of the current collector is 6.25 μm2.
References :
[1] M. Duduta, B. Ho, V. C. Wood, P. Limthongkul, V. E. Brunini, W. C. Carter, and Y. Chiang, Adv. Energy Mater., 1(2011) 511
[2] M. A. Quiroga, and A. A. Franco, J. Electrochem Soc.
161(7) (2015) E73.
[3] G. Blanquer, Y. Yin, M. A. Quiroga, and A. A. Franco, J. Electrochem Soc., 163(3) (2016) A329
[4] S. Hamelet, D. Larcher, L. Duport, and J. M. Tarascon, J. Electrochem Soc., 160(3) (2013) A516.
[5] G.Shukla, D. del Olmo Diaz, V. Thangavel, and A. A. Franco, in preparation (2016)

Figure 1
New Process to Synthesize Rh2S3 Precursor for Rhxsy Catalyst for HER/HOR in HBr Solution By Na2S and Pretreated Carbon
Authors: Li Yuanchao , Nguyen Trung Van 
Published: February 2020

There has been growing interest in electrical energy storage because of the challenge of integrating intermittent renewable energy sources such as wind and solar into the electrical grid. The hydrogen-bromine reversible fuel cell system serves as a promising technology to meet this need because of its high round-trip conversion efficiency and low cost. Since the commonly used catalyst, platinum, is not stable in the corrosive HBr and Br2 environment, an alternative catalyst which is durable and active is needed. RhxSy catalyst has been found to be stable in the HBr/Br2 environment1,2.
The conventional synthesis of RhxSy/C has been developed by De Nora3, where (NH4)2S2O3 serves as sulfur source and XC72R is the carbon support. This kind of catalyst, however, has large and broad particle sizes (12-40 nm) and consequently low mass specific active area (< 10 m2/g) for HOR. Moreover, the exchange current density for the HOR/HER is also relatively lower than the commercial RhxSy catalyst from BASF, which can be seen from Figure 1. Other research groups4,5 have shown that smaller particle size can be achieved if preferable surface for precipitation of Rh cation is provided. Figure 2 shows the mass specific active surface area (ECSA) of the catalyst prepared with pretreated carbon and the commercial Rh2S3 synthesis process. In addition to the ECSA/mass enhancement, Na2S also serves as an appropriate sulfur source to modify the crystal structure of RhxSy, as shown in Figure 3. The modified crystal structure leads to improved exchange current density. This presentation will discuss the attempt to synthesize the RhxSy catalyst with pretreated carbon and Na2S. The characteristics and performance of this catalyst will also be presented.

Reference

1. J. Masud, T. Van Nguyen, N. Singh, E. McFarland, M. Ikenberry, K. Hohn, C.J. Pan, and B.J. Hwang, Journal of the Electrochemical Society, 162, F455 (2015).
2. A. Ivanovskaya, N. Singh, R.-F. Liu, H. Kreutzer, J. Baltrusaitis, T. Van Nguyen, H. Metiu, and E. McFarland, Langmuir, 29, 480 (2013).
3. De Nora Elettrodi S.P.A, Synthesis of Noble Metal, Sulphide Catalysts in A Sulfide Ion- Free Aqueous Environment, US6967185 B2, 2005.
4. A. Eguizabal, L. Uson, V. Sebastian, J.L. Hueso, and M.P. Pina, RSC Advances, 5, 90691 (2015).
5. M.S. Shafeeyan, W.M.A.W. Daud, A. Houshmand, and A. Shamiri, Journal of Analytical and Applied Pyrolysis, 89, 143 (2010).

Acknowledgments

The work presented herein was funded in part by the Advanced Research Projects Agency-Energy (ARPA-E), U.S. Department of Energy, under Award Number DE-AR0000262 and the National Science Foundation under Grant No. EFRI-1038234 and No. 1416874, as a sub-award from Proton Onsite.

Figure 1
Scaling Considerations in All-Iron Flow Batteries
Authors: Sinclair Nicholas S. , Murphy Joseph , Savinell Robert F. , Wainright Jesse S. 
Published: February 2020

In recent years, the deployment of renewable energy sources, development of smart grid technology and advances in electrified transportation have resulted in a surge in markets for large-scale stationary energy storage. Several factors contribute to the demand for large-scale energy storage, including capital costs of managing peak demands, integration of renewable energy sources and investments needed for grid reliability. Although hydroelectric is one of the most common types of energy storage, flow batteries offer a much more desirable alternative, due to scalability and location flexibility. A number of studies and demonstration projects have been carried out in the field of flow batteries, in particular with the vanadium [1,4], and iron/chromium[2-4] chemistries and these and other systems are in the first stages of commercial deployment. In this presentation we will discuss the scale-up an all iron flow battery, focusing on two issues in particular, flow distribution and hydrogen generation/recombination.
Flow distribution is a scaling concern in all flow battery systems both on a cell to cell level within a stack and within an individual cell. This investigation utilizes the all iron chemistry to investigate the effects of flow distribution within a single cell on cell performance and the pressure drop associated pumping costs of achieving a more even flow distribution within a cell. These effects are considered in the context of transitioning from a 50cm2 lab scale cell to a 1100cm2 commercial scale prototype. An optimization can be achieved between flow uniformity and pumping losses.
Hydrogen evolution is a parasitic reaction in many chemistries that can have a significant effect on lifetime. We have developed a simple in-tank system that captures and re-oxidizes hydrogen to maintain electrolyte stability and demonstrated this concept on a laboratory scale.[5] This investigation looks into scaling considerations and their effect on the hydrogen recombination system. Specifically, the relationship between head space, gas recirculation and the effectiveness of the reactor are considered.
[1] G. Codina, J. Perez, M. Lopez-Atalaya, J. Vasquez, and A. Aldaz, J. Power Sources, 48, 293 (1994).
[2] S. Takahashi and T. Hiramatsu, J. Power Sources, 17, 55 (1986).
[3] M. Futamata, S. Higuchi, O. Nakamura, I. Ogino, Y. Takada, and S. Okazaki, J. Power Sources, 24, 137 (1988).
[4] M. Skyllas-Kazacos, M. H. Chakrabarti, S. A. Hajimolana, F. S. Mjalli and M. Saleem, J. Electrochem.Soc., 158, 8 (2011).
[5] S, Selverston, R. F. Savinell and J. S. Wainright, J. Power Sources., 324, 674, (2016).
A New Membrane-Less Porous Electrode Cell Design for Zinc-Iodide Redox Flow Battery
Authors: Shakeri Hosseinabad Fatemeh , Fofana Daouda , Li Jialang , Roberts Edward P.L. 
Published: February 2020

A new flow field using a flow through porous electrode for membrane-less flow battery has been evaluated using the zinc-iodide redox system. The flow through the porous electrode enables good mass transport at the zinc electrode, and thus good performance was obtained. The flow through arrangement also allowed separation of the charged species without the use of a membrane. An electrolyte system of zinc-iodide, iodine, and zinc chloride was used. A 5cm2 carbon paper (39AA SIGRACET) was used as the electrode. Cyclic voltammetry studies were carried out for the electrolyte system using a glassy carbon working electrode in the range of -2 to 2V (versus Ag/AgCl) , and the effect of zinc-iodide concentration and different range of scan rate was investigated. Mass transfer modeling of the zinc iodine system during the discharge process was carried out and the concentration profile was obtained. The variation of zinc-iodide concentration along the length of the cathode, resulted in spatial variation in mass flux and current density. The 2-D model is reduced to an equivalent 1-D model for the concentration profile by using realistic boundary conditions at the electrode along with using similarity technique. The effect of Péclet number, zinc-iodide concentration and flow rate on columbic and energy efficiency of the new cell will be presented.
Development of an Advanced Zinc-Air Flow Battery
Authors: Mahlendorf Falko , Müller Christoph , Fuchs David , Heinzel Angelika 
Published: February 2020

In recent years, zinc-air flow batteries have regained importance as promising energy storage system for mobile and stationary applications. This revived importance is driven by the increased demand of high-performance, efficient, safe and environmentally friendly energy storage solutions to meet the challenges of modern energy supply systems with high amounts of renewable energy. These energy storage systems need to address variable power, capacity and profitability requests. Zinc-air batteries with a specific energy density higher than lithium-ion and low cost, highly available, eco-friendly active materials are suitable to fulfill these requirements. The use of a flow battery type with zinc-particles suspended in alkaline solution (zinc-slurry) in addition with oxygen reduction electrodes developed for the chloralkali process allows the development of high-power zinc-air batteries. This setup also enables the independent scaling of capacity and power.
The cooperative research project ZnMobil, supported by the Federal Ministry of Economic Affairs and Energy in Germany, combines the experience of industrial and academic partners (Covestro Deutschland AG; Grillo-Werke AG; VARTA Microbattery GmbH; Accurec Recycling GmbH; Technical University Freiberg, Gottfried Wilhelm Leibniz University Hannover; University of Duisburg-Essen; The fuel cell research center ZBT GmbH) to develop a low-cost zinc-air flow battery with high performance.
Here we present the electrochemical performance of the new zinc-air flow battery with respect to different zinc-slurry compositions. The battery system consists of a 100 cm² copper plate as current collector for the zinc-suspension electrode and an oxygen reduction electrode with gas-diffusion layer (supplied by Covestro). The zinc-slurry contains zinc particles (supplied by Grillo) suspended in alkaline solution (30 wt-% KOH) and stabilized with polyacrylic acid.
Current voltage curves and depth of discharge were measured as a function of slurry composition (e.g. zinc content, additives) and different flow velocities of the zinc slurry. Corresponding zinc-slurry conductivities were evaluated in a flow-through conductivity measurement setup. Depending on the selected parameters, it is possible to achieve discharge current densities higher than 4 kA/m².