bluuebunny/crossref_metadata_2025 huggingface dataset:
Heat to H2
Authors: Skilbred Ellen Synnøve , Krakhella Kjersti Wergeland , Haga Ida Johanne Molvik , Hillestad Magne , Serrano Gonzalo del Alamo , Pharoah Jon G. , Burheim Odne Stokke
Published: February 2020

Renewable energy sources are often intermittent or unavailable for the end user, making energy storage vital. One way to store the energy is in hydrogen, and our aim is to produce hydrogen through reverse electrodialysis (RED) [1, 2, 3]. RED is a technology that uses concentration differences to create electrical energy. This is achieved through the use of ion-conducting membranes, where the membranes separate two solutions while producing an electric potential. Moreover, RED can be used to produce hydrogen in addition to electric energy. An illustration of the RED-cell is given in Figure 1.

Any salt can be used for this purpose, as the potential is dependent on concentration differences only, not the specific solution used. This project utilises waste heat of low quality to build up and maintain the concentration differences (see Figure 2). The whole process is carried out in a closed system, where heat will be the only external input (in addition to electricity used for pumps). The closed energy storage system can easily be installed in connection with industrial processes where waste heat is available.

As ions are transported from the concentrated to the diluted solution, the potential will decrease. Two separation techniques are evaluated for increasing the concetration difference, namely evaporation at high temperature or precipitation at low temperature. The respective process sketches are shown in Figure 2.

This research investigates the suggested system with either NaCl or KNO3 as active solutions and temperature levels. Parts of the experiments include an end goal of creating sufficient potentials for hydrogen evolution, hence creating a technology where low-grade waste heat is converted to hydrogen.

[1] O. S. Burheim, J. G. Pharoah, D. Vermaas, B. B. Sales, K. Nijmeijer, and H. V. Hamelers, "Reverse electrodialysis," Encyclopedia of Membrane Science and Technology, 2013.

[2] M. F. M. Bijmans, O. S. Burheim, M. Bryjak, A. Delgado, P. Hack, F. Mantegazza, S. Tenisson, and H. V. M. Hamelers, "CAPMIX - Deploying capacitors for salt gradient power extraction," Energy Procedia, vol. 20, pp. 108-115, 2012.

[3] O. S. Burheim, Engineering Energy Storage. Academic Press 2018, 2017.

Figure 1
Some New Territories of Topochemistry for Electrodes in Sustainable Batteries
Authors: Ji Xiulei , Wu Xianyong , Dong Shengyang , Li Zhifei , Rodríguez Pérez Ismael Antonio , Wang Xingfeng , Jian Zelang , Lu Jun , Greaney P. Alex
Published: February 2020

Energy storage is the absent enabler to facilitate the proliferation of renewable-but-intermittent solar and wind energy. There is one primary metric for stationary storage: levelized energy cost over the life time of devices. It is, thus, a must to rely on earth-abundant elements, which rules out lithium-based devices for the grid-scale storage purposes as lithium is rare and its excavation is geopolitically challenged. This warrants attention for alternative rechargeable batteries. At Oregon State University, we seek fundamental understanding of design principles of electrodes for new sustainable batteries. We take an iterative approach to gain knowledge by integrating rational syntheses, advanced characterization, including synchrotron x-ray, neutron scattering, and associated pair distribution function studies, as well as DFT calculations. In this talk, I will talk about our recent results on the mechanisms of Na-ion and K-ion storage in non-graphithic carbon. I will introduce a design principle of hard carbon anode for Na-ion batteries based on its structure-property correlations. I will introduce limitations of carbon anode materials for K-ion storage and strategies in addressing them. I will discuss the relevance of organic solids as cathode of dual-ion batteries. Additionally, I will share new results on the emerging hydronium-ion batteries and ammonium-ion batteries.
Probing the Size-Exclusion Properties of Redox Flow Battery Separator Membranes Using Metal-Ligand Complexes
Authors: Kushner Douglas I. , Tucker Michael C , Kusoglu Ahmet , Weber Adam Z.
Published: February 2020

Redox flow batteries (RFBs) are among one of the most promising technologies being explored for grid-scale energy storage from discontinuous power sources such as wind and solar.1 This has resulted in a need for continued development and understanding of electrolytes and membranes employed in RFBs as a means of improving performance while reducing cost. New approaches in membrane design rely on size-exclusion to reduce parasitic losses resulting from water and electrolyte crossover that presently plagues ionomer membranes within the perfluorosulfonic acid (PFSA) family (e.g. Nafion, Aquivion, and 3M PFSA).2 The structure-property relationships of PFSAs are well-known and studied,3 providing the initial framework for utilization of ligands to understand transport through next-generation membranes.

In this work, we discuss our efforts in developing a systematic approach towards probing the effective size-exclusion properties of the polymeric membranes by employing iron-ligand complexes. A series of aminopolycarboxylic acid ligands, shown in Figure 1, that strongly complex with iron were selected to explore the effect of molecule size on crossover in PFSAs with varying domain sizes, controlled via side chain length. We show decreases in permeability with increased size of the iron-ligand complex, providing information regarding the hydrophilic domain network of these ionomer membranes. By measuring the crossover of these complexes using diffusion cells, we explore the size-exclusion properties of PFSAs using relevant molecules for future iron RFB applications.

Acknowledgements

This work was funded as a sub-contract under the Integration and Optimization of Novel Ion-Conducting Solids program (IONICS), by the Advanced Research Projects Agency-Energy (ARPA-E), of the US Department of Energy under award number DE-AR0000773.

Perry, M. L.; Weber, A. Z., Advanced Redox-Flow Batteries: A Perspective. J Electrochem Soc
2016,
163 (1), A5064-A5067.

Darling, R.; Gallagher, K.; Xie, W.; Su, L.; Brushett, F., Transport Property Requirements for Flow Battery Separators. J Electrochem Soc
2015,
163 (1), A5029-A5040.

Kusoglu, A.; Weber, A. Z., New Insights into Perfluorinated Sulfonic-Acid Ionomers. Chem Rev
2017,
117 (3), 987-1104.

Figure 1
Synthesis of Few Layered MnO2 Nanosheets Encapsulated TiO2 Nanorods Electrode for Supercapacitor Application
Authors: Rajagopal Rajesh , Ryu Kwang-Sun
Published: February 2020

Supercapacitors have attracted in the field of portable electronic devices and electronic vehicles due to its long cycle stability and high power density. To achieve high energy density, researchers concentrated on the development of transition metal oxide and its composites based electrode material for supercapacitor device fabrication. Among them, MnO2 and TiO2 got great importance due to its low cost and environment friendly nature. Further, use of binary metal oxide nanocomposite electrode materials has been received much attention due to its exceptional physical properties and potential applications. In this work, MnO2 nanosheets encapsulated TiO2 nanorods have been synthesized by two step hydrothermal process for supercapacitors. Initially, TiO2 nanorods were synthesized by ion intercalation assisted hydrothermal process and the MnO2 nanosheets were encapsulated over the TiO2 nanorods by the simple hydrothermal technique with controlled pH condition. The physio chemical properties of the synthesized MnO2 nanosheets encapsulated TiO2 nanorods were studied by various characterization techniques. The crystalline nature of the synthesized material was studied by powder X-ray diffraction technique. Specific surface area and porous nature of the material was studied by nitrogen adsorption techniques and the measured specific surface area of the synthesized MnO2 nanosheets encapsulated TiO2 nanorods is 118 m2 g-1. Few layered MnO2 nanosheets and its encapsulation over TiO2 nanorods was confirmed by field emission electron microscope (FESEM) technique and the elemental analysis was carried out using EDS analysis. The electrochemical behavior of the synthesized MnO2 nanosheets encapsulated TiO2 nanorods was studied by cyclic voltammetry (CV), charge – discharge and electrochemical impedance techniques in 1 M Li2SO4 aqueous electrolyte. The quasi – rectangular shaped cyclic voltammetry curve was observed and confirmed the capacitive behavior of the synthesized material. The specific capacitance values of the synthesized MnO2 nanosheets encapsulated TiO2 nanorods electrode material was calculated from Galvanostatic charge-discharge technique at a various applied current density of 1 to 5 A g-1. The synthesized MnO2 nanosheets encapsulated TiO2 nanorods electrode shows high specific capacitance and energy density value of 1388.28 F g-1 and 123.41 Wh. kg-1, respectively at the applied current density of 1 A g-1. The electrochemical impedance analysis was performed within the frequency range of 10 mHz to 100 kHz to analyze the resistive and capacitive nature of the synthesized electrode material. The plotted Nyquist, Bode angle and Bode absolute plots confirmed the existence of pseudo capacitance and EDLC nature of the electrode material. The above results confirmed that the synthesized MnO2 nanosheets encapsulated TiO2 nanorods is a suitable material for supercapacitor application.
Highly Ion Selective Membranes for Aqueous Redox Flow Batteries
Authors: Gigli Matteo , Mecheri Barbara , Branchi Mario , Tizzoni Anna Chiara , Licoccia Silvia , D'Epifanio Alessandra
Published: February 2020

Redox flow batteries (RFB) are one of the most promising energy storage systems used to overcome the intermittence limitations of renewable energies. In RFB, electrical energy production is supplied by two electrolytes that undergo redox reactions in two half cells. These latter are separated by a membrane, whose primary function is to allow the proton flow, while preventing the transport of the active species to avoid battery self discharge.

Traditional aqueous RFBs, such as all-vanadium (redox battery, VRB) [1], or more innovative anthraquinone-disulphonic acid (AQDS) combined with the Br2/Br- redox couple [2], used Nafion membranes as separator because of the high ion conductivity and chemical stability of this polymer. However, its low selectivity causes a significant drop of battery performances over time.

In this work, several ionic exchange membranes (CEM) have been investigated and their performances have been compared to Nafion. Hydrocarbon-based membranes have been tested because highly rigid aromatic macromolecular chains and tinier ionic clusters are expected to decrease electrolyte crossover. In this framework, the use of sulfonated poly(phenylene sulfide sulfone) polymers (sPSS) as chemically stable ion-conducting membranes for aqueous RFB is proposed [3].

To further increase membrane selectivity, sPSS has been loaded with sufonated hypercrosslinked polystyrene nanoparticles (sHCP). sHCP have been synthesized through Friedel-Craft alkylation to obtain HCP, followed by post-functionalization to attach sulfonic groups. sHCP structure and morphology has been assessed by TGA, FT-IR, SEM and BET.

Composite (sPSS-sHCP) and pristine (sPSS) membranes have been characterized ex situ and in operando for all vanadium Redox Flow Battery applications, through galvanostatic cyclation at a current density of 150 mA/cm2.

The results evidenced the higher performances of the composite membranes with respect to sPSS and Nafion, resulting in a self-discharging time over 3.5x higher and capacity fading about 33% lower.

Acknowledgements

The present work was carried out with the support of the “European Union's Horizon 2020 research and innovation programme”, under H2020-FTIPilot-2015-1 (Grant Agreement n. 720367-GREENERNET) and GREENERSYS project supported by Provincia Autonoma di Trento ITALY

References

[1] M. Skyllas-Kazacos, M. Rychcik, R.G. Robins, A.G. Fane, M.A. Green, New all-vanadium redox flow cell, J. Electrochem. Soc. 133, 1057-1058 (1986)

[2] B. Huskinson, M. P. Marshak, C. Suh, S. Er, M. R. Gerhardt, C. J. Galvin, X. Chen, A. Aspuru-Guzik, R. G. Gordon, and M. J. Aziz, Nature, 505, 195 (2014).

[3] M.Branchi, M. Gigli, B. Mecheri, D. de Porcellinis, S. Licoccia and A. D'Epifanio

J. Mater. Chem. A, 5, 18845 (2017)
A High Capacity, Room Temperature Hybrid Flow Battery Consisted of Liquid Na-Cs Anode and Aqueous NaI Catholyte
Authors: Liu Caihong , Shaw Leon
Published: February 2020

The development of renewable energy has become a high priority for environmental sustainability and energy independence. Some renewable energies (e.g., solar and wind), however, are intermittent, and require integration with energy storage systems to provide predictable and dispatchable supply of electricity. Redox flow batteries (RFBs) are excellent candidates for such grid-scale energy storage of electricity. However, the state-of-the-art RFBs have low volumetric and gravimetric energy densities (20 – 33 Wh/L and 15 – 25 Wh/kg) and their costs are high for many applications. To address these issues, we propose a novel concept of hybrid flow batteries consisting of a molten Na-Cs anode and an aqueous NaI catholyte separated by a NaSICON membrane. A number of carbonaceous electrodes are studied using cyclic voltammetry (CV) for their potentials as the positive electrode of the aqueous NaI catholyte. The charge transfer impedance, interfacial impedance and NaSICON membrane impedance of the Na-Cs ║ NaI hybrid flow battery are analyzed using electrochemical impedance spectroscopy (EIS). The performance of the Na-Cs ║ NaI hybrid flow battery is evaluated through galvanostatic charge/discharge cycles. This study demonstrates, for the first time, the feasibility of the Na-Cs ║ NaI hybrid flow battery and shows that the Na-Cs ║ NaI hybrid flow battery has the potential to achieve the following properties simultaneously: (i) an aqueous NaI catholyte with good cycle stability, (ii) a durable and low impedance NaSICON membrane for a large number of cycles, (iii) stable interfaces at both anode/membrane and cathode/membrane interfaces, (iv) a molten Na-Cs anode capable of repeated Na plating and stripping, and (v) a flow battery with high Coulombic efficiency, high voltaic efficiency, and high energy efficiency.
Electrolytic Processing of Kraft Black Liquor- Mass Transfer Investigation
Authors: Cloutier Jean-Noël , Paris Jean , Savadogo Oumarou , Perrier Michel , Labrecque Raynald , Champagne Pascal
Published: February 2020

As an alternative to the chemical approach reducing the pH of black liquor to precipitate lignin using carbon dioxide and sulfuric acid, we have developed an electrochemical avenue for lowering pH while recovering caustic. It includes electrolytic treatment of black liquor that reduces its alkalinity to the critical point of lignin precipitation without using chemicals of external source. In this study, we modeled the mass transfer phenomena of most important ions through the membrane during electrolysis. We report on the investigation of sodium, protons hydroxyls ions and pH profiles across the membrane under typical operating conditions along with sodium transfer performance.
Disinfection of Seawater and Its Neutralization Using Seawater Battery
Authors: Park Jeong-Sun , Park Jehee , Hwang Soo Min , Kim Youngsik
Published: February 2020

Seawater disinfection is a commonly used technology in many functional systems operated in the seawater environment to prevent biofouling due to the formation of biofilms by microorganism growth, which induces an operational problem in the long-term. there are three kinds of conventional disinfection technologies, physical (UV), chemical (ozone and Cl), and electrochemical ones with no use of chemical additive. Conventional disinfection methods have many issues to be resolved, such as high energy consumption, low disinfection efficiency, and an additional neutralization process before discharging the treated water. Therefore, it is highly required to develop an energy-efficient disinfection technology which enables a high disinfection efficiency, as well as simple neutralization process to remove toxic disinfectants, such as total residual oxidant (TRO) in the treated water.

In this work, we introduce a new type of electrochemical disinfection system, which functions both seawater disinfection and neutralization without any chemical treatments, named as the combined system for disinfection and neutralization (CSDN). By employing a rechargeable seawater battery system[1-3], the CSDN conducts seawater disinfection and the neutralization of remained TRO during charge and discharge processes, respectively. The disinfection efficiency of total chlorine (TC), such as HOCl and OCl, produced during charging is evaluated by using Escherichia coli and Enterococcus aquamarines. The remained TRO in disinfected seawater is removed by discharging, where the TRO (TC) are reduced into chloride ions, while providing electricity to external loads. The mechanisms behind the generation and neutralization of TRO are discussed. The proposed CSDN would provide an effective solution to lower energy consumption for seawater disinfection through the battery technology and an interdisciplinary approach to connect between the disinfection and electrochemical energy storage technologies.

References :

[1] Kim, J.-K.; Mueller, F.; Kim, H.; Bresser, D.; Park, J.-S.; Lim, D.-H.; Kim, G.-T.; Passerini, S.; Kim, Y. Rechargeable-Hybrid-Seawater Fuel Cell. NPG Asia Mater. 2014, 6, e144.

[2] Kim, H.; Park, J.-S.; Sahgong, S. H.; Park, S.; Kim, J.-K.; Kim, Y. Metal-Free Hybrid Seawater Fuel Cell with an Ether-Based Electrolyte. J. Mater. Chem. A 2014, 2, 19584−19588.

[3] Kim, J.-K.; Mueller, F.; Kim, H.; Jeong, S.; Park, J.-S.; Passerini, S.; Kim, Y. Eco-friendly Energy Storage System: Seawater and Ionic Liquid Electrolyte. ChemSusChem 2016, 9, 42−49.
In-Situ De-Aeration Towards Performance Stability of Capacitive Deionization Cells
Authors: Caudill Landon , Omosebi A. , Gao X. , Landon James , Liu K.
Published: February 2020

Carbon-based Capacitive Deionization (CDI) is an emerging treatment method for saline waters with ion concentration at or below brackish levels. This technology works similarly to a parallel plate aqueous capacitor in that the dissolved ions are removed from solution through an applied electric potential and adsorbed onto the active surface of the electrodes. Upon removal or reversal of the applied potential, the ions re-dissolve, creating a concentrated stream (1). One setback in the commercialization of CDI technology is performance stability, which has mainly been attributed to a combination of carbon oxidation at the anode (positive electrode) and oxygen reduction at the cathode (negative electrode)(2-4). This work explores an in-situ method for evacuating trapped air from the electrode’s pores towards mitigating Faradaic reactions and increasing the long-term stability of CDI systems.

The flow through CDI cell used in this study utilized symmetric, pristine, carbon electrodes obtained from Kynol®. The CDI system, fitted with a pressure regulator and gauge, allows for operation at elevated pressures, up to 60 psi, within the cell. Figure 1, depicts the CDI system components with the pressurized and non-pressurized regions highlighted. The natural pressure gradient that occurs across the cell due to flow resistance remains constant because the entire cell lies within the pressurized portion of the system. This operating method takes advantage of Henry’s Law (where more dissolved oxygen is found at higher pressure) removing oxygen from the cell.

Initial data, shown in Figure 2, demonstrates the response of dissolved oxygen to changes in system pressure for a ~5mM aerated sodium chloride solution. A CDI system, treating the same concentration sodium chloride solution, operating at increased pressure demonstrates a similar increase in dissolved oxygen, which decays back once the trapped air is removed.

References

M. E. Suss, S. Porada, X. Sun, P. M. Biesheuvel, J. Yoon and V. Presser, Energy & Environmental Science, 8, 2296 (2015).

I. Cohen, E. Avraham, Y. Bouhadana, A. Soffer and D. Aurbach, Electrochimica Acta, 153, 106 (2015).

C. Zhang, D. He, J. Ma, W. Tang and T. D. Waite, Water research, 128, 314 (2017).

A. Omosebi, X. Gao, N. Holubowitch, Z. Li, J. Landon and K. Liu, Journal of The Electrochemical Society, 164, E242 (2017).

Figure 1
Electrochemical Removal of Copper from Regenerated Pickling Solutions of Steel Plants
Authors: Karakaya Esra , Aras Mustafa Serdal , Erdogan Metehan , Karagul Sedef , Ersoy Merve , Karakaya Ishak
Published: February 2020

The spent pickle liquor contains the dissolved metal salts of iron, chrome, copper, nickel and zinc [1]. The acid can be cleaned from its impurities, except for its copper ion, by the regeneration process. When the copper concentration of the pickling solution exceeds the level of about 100 ppm, the copper inside the solution replaces the iron in the steel and copper starts plating randomly on the metal surface in the following pickling processes. Because of the plating problem, the acid needs to be discard from the acid line. By adding fresh acid to the line the discarding can be delayed [2]. An electrochemical procedure was conducted to overcome the cementation problem experimentally in an environmental and economical way. Electrowinning of dilute copper from strong acid solution is a challenge in this case so the optimum current density, electrolysis duration and the electrode materials were determined in this study.

It was found that increase in the current density and electrolysis duration increases the copper removal, but changes the morphology of deposits. A slower compact deposition procedure was selected to achieve continuous removal of copper instead of faster discontinuous powder deposition from the regenerated pickling solutions of steel plants.

References

[1] A. Agrawal, S. Kumari, and K. K. Sahu, “Iron and Copper Recovery/Removal from Industrial Wastes,” Metal Extraction and Forming DiVision, National Metallurgical Laboratory, India, 2009.

[2] M. A. Nicholls, Z. Koont, B.D. Nelson, D. Bray and J. Felker (2008), Copper Plating Phenomenon During the Pickling of Steel. Pickling and Cold Rolling Department, ArcelorMittal Dofasco Inc., Hamilton, Ont., Canada.
Ordered Three Dimensional Electrodes for Enhanced Mass Transfer
Authors: Hereijgers Jonas , Lölsberg Jonas , Wessling Matthias , Breugelmans Tom
Published: February 2020

Over the last decade, the use of nanotechnology in electrochemical catalysis has become extreme popular [1]. Sole electrocatalytic nanoparticles, however, do not yet constitute an electrode. Hence, deposition on a conducting support structure is indispensable. While the electrocatalytic activity is in general well understood using typical electrochemical techniques such as cyclic and linear voltammetry whether or not coupled with controlled mass transfer conditions like rotating disk electrodes, the impact of concentration polarization is often neglected. Operating under current limiting regime, mass transfer enhancement in electrochemical reactors is a key factor not only for current density but also for the selectivity and stability [2]. Inducing convective transport, however, is limited to the incorporation of turbulence promoters. Either stating an increase in inter-electrode distance or a large power dissipation to pump the feed.

Looking at electrochemical reactors (e.g. fuel cell, chloor-alkali process, water electrolyzer) the conductive support typically consist of a flat substrate with the electrolyte flowing sideways along the electrode [3]. Inevitably a stagnant boundary layer arises which reacting species have to surpass to reach the electrocatalytic surface, even when using turbulence promotors. As transport across this stagnant layer is solely due to diffusion it has a major impact on the mass transfer resistance and concomitantly on the position of the limiting current plateau. However, when the electrode is no longer considered as a flat substrate a plethora of options arise, where not only the surface area can be increased, but also where the electrode itself can provoke mixing effects, reducing this boundary layer.

In the present work such integrated mixer and electrode configurations have been constructed and evaluated using additive manufacturing technology. Doing so these electrode mixers shift the limiting current plateau with over 70%. At the one hand this is attributed due to shear forces reducing the stagnant boundary layer, at the other hand as no longer a turbulence promotor or even a spacer is required the inter-electrode distance can be reduced to sub-millimeter range, having a beneficial impact on the ohmic resistance.

References:

A. Kloke, F. Von Stetten, R. Zengerle, S. Kerzenmacher, Strategies for the fabrication of porous platinum electrodes. Adv. Mater.
23, 4976–5008 (2011).

C. J. Brown, F. C. Walsh, J. K. Hammond, D. Robinson, Local mass transport effects in the FMO1 laboratory electrolyser. J. Appl. Electrochem.
22, 613–619 (1992).

D. Pauwels et al., The application of an electrochemical microflow reactor for the electrosynthetic aldol reaction of acetone to diacetone alcohol. Chem. Eng. Res. Des.
128, 205–213 (2017).
Electrochemical Behaviour of Iron in Molten Oxides
Authors: Judge William David , Azimi Gisele
Published: February 2020

Owing to their versatility, iron and steel are among the most widely used engineering materials with about 1.6 billion tonnes produced in 2016. The conventional extraction process based on blast furnaces relies heavily on carbon, thus the production of iron and steel accounts for 4-7% of all anthropogenic CO2 emissions [1]. Due to recent environmental regulations and global action to mitigate climate change, attention has begun to target the environmental aspects of the steelmaking technology, and to this end research activities have begun around the world to develop breakthrough environmentally sound low carbon alternative processes. Among proposed processes, the most promising is based on molten electrolysis, because electricity has the potential to be carbon-free when produced from renewable resources.

Within the electrochemical regime, molten oxides are an attractive medium for extraction of iron for a number of reasons [2]. Their high solubilizing power allows iron ore to be directly fed to the electrolytic cells, while their low vapor pressure allows electrolysis to be conducted above the melting point of iron, which greatly improves throughput, and most importantly, oxide ions in the melt can be discharged as environmentally benign oxygen gas if anode materials are inert. Consequently, there has been considerable effort to develop a molten oxide electrolysis process for iron [3]. However, there remain fundamental uncertainties regarding the electrochemistry of iron in molten oxides [4], thus the process has not yet been commercialized.

In this work, we present recent fundamental and experimental investigations into the electrochemical behaviour of iron in molten oxides, with the aim of understanding mechanisms that govern electrolysis. Attention is given to the design and testing of supporting electrolytes to minimize electronic conduction in the melt and improve the current efficiency of the process. At the same time, the performance of supporting electrolytes with respect to viscosity, surface tension, diffusivity, ionic conductivity, and liquidus temperature are considered. The results of fundamental investigations were used to strategically direct experimental investigations.

[1] Energy Technology Perspectives 2017. International Energy Agency: Paris (2017): 76-79.

[2] D.R. Sadoway. "New Opportunities for Metal Extraction and Waste Treatment by Electrochemical Processing in Molten Salts." J. Mater. Res. 10 (1995): 487-492.

[3] A. Allanore. "Features and Challenges of Molten Oxide Electrolytes for Metal Extraction." J. Electrochem. Soc. 162 (2015): E13-E22.

[4] W.D. Judge, A. Allanore, D.R. Sadoway, and G. Azimi. "E-logp
O2 diagrams for ironmaking by molten oxide electrolysis." Electrochim. Acta 247 (2017): 1088-1094.
Tunability of the Photogenerated Charge Carrier Density on Semiconductors By in-Situ Electrochemical Treatments
Authors: Liu Xu , Real Jesús Díaz , Mérida Walter
Published: February 2020

Nanostructured semiconductors are widely studied materials due to their wide range of potential applications, such as solar energy conversion. In the latter, a determining characteristic for semiconductors is the generated photocurrent, which is greatly influenced by the synthetic route and subsequent treatments. In this work, we present an in-situ potentiostatic and potentiodynamic approach to modify the photoelectrocatalytic properties of nanostructured TiO2 electrodes. The effect of the morphology was studied by comparing a nanotubular and nanorod particulate TiO2. A potentiodynamic (cyclic voltammetry) and potentiostatic (differential pulsed amperometry) were used to modify the electrodes in 0.5 M H2SO4. The photogenerated charge carriers separation was studied by CV, LSV and CA. Self-doping can tune the electronic and band structures of semiconductor photocatalysts like binary metal oxides. Thus, a change in the capacitance was observed after the reductive self-doping (SD) treatment that was studied by recording Mott-Schottky plots. The morphological, structural, and optical properties were characterized by SEM, XRD/Rietveld refining, XPS, respectively. The observed behaviors from electrochemical measurements suggested that morphology has an important in the capacitive properties. In the meantime, nanorod reacted quickly to light. Experimental results confirmed that self-doping could change the electronic structures to intrinsically improve the optical absorption property and charge transfer ability, thus enhancing the photocatalytic activity of semiconductors. This successful band structure tailoring example of semiconductors suggests the electrochemical treatments represent a facile and systematic technique to be general to develop novel visible light driven photoelectrocatalysts with enhanced performances.
(Invited) Stochastics in Energy Storage: Interface to Microstructure
Authors: Mukherjee Partha P. , Mistry Aashutosh N , Smith Kandler
Published: February 2020

Porous electrodes are central to electrochemical energy storage systems, such as lithium-ion batteries. Operational characteristics, including performance, life, and safety, of such batteries depend on the electrode microstructural complexities and associated stochasticity. The electrode microstructure depends strongly on the arrangement of the constituent phases (active material, conductive additives, binder, and voids containing electrolyte) resulting from the processing conditions. For example, solvent evaporation dynamics during the electrode slurry drying introduces stochasticity in local distribution of these solid phases. The pore-scale complexations of the transport-electrochemistry interaction may be further affected due to the interfacial stochasticity resulting from inhomogeneous distribution of the conductive binder domains at the active material – electrolyte interface, as shown schematically in the figure below. In this talk, a holistic perspective on the role of stochasticity, spanning across interface and microstructure scales, will be discussed in the context of lithium-ion battery electrode properties and performance.

Figure 1
(Invited) Modeling Glassy Electrolytes for All-Solid-State Sodium Ion Batteries
Authors: Dive Aniruddha , King Clarence C , Martin Steve W , Beckman Scott P , Banerjee Soumik
Published: February 2020

Solid-state sodium ion batteries, a relatively safe and potentially cost-effective technology for electrical grid-scale energy storage, has attracted significant scientific attention in recent times. However, identifying solid electrolytes with high ionic conductivity at room temperature is a requirement in order to commercialize solid state sodium ion batteries. Amorphous sulfide glasses are considered as promising candidates with relatively high ionic conductivity. However, the properties of these electrolytes are highly sensitive to the chemical composition. We present a multiscale approach, which employs atomistic simulations coupled with mesoscale modeling, to analyze and evaluate transport properties of solid glassy electrolytes. As a model system, we studied sodium sulfide – silicon sulfide [xNa2S – (1-x)SiS2] based electrolytes with varying compositions. We determined the ionic conductivities and activation energies for sodium ion hops using ab initio and classical molecular dynamics (MD) approach. These simulations provide fundamental insights into ion conduction mechanisms as well as help to correlate ionic conductivity with glass structure and composition. We further developed a Monte Carlo model to scale up our calculations to a much larger length-scales that are inaccessible by molecular dynamics simulations. Crucial inputs such as Na+ ions distribution and migration energies obtained from classical and ab initio MD served as key inputs to the Monte Carlo model. This model accurately predicts the ionic conductivity of the glasses in agreement with experimental values. Overall, the multiscale model shows excellent promise in identifying optimal glassy electrolytes for sodium ion batteries.
Thermodynamic and Kinetic Database for Hydration, Protonic Diffusion and Stability in Doped-BaHfO3 As High-Temperature Proton Conducting Electrolyte
Authors: Zhang Lei , Liu Meilin
Published: February 2020

Perovskite-type proton conducting materials is widely used as solid state electrolyte in Solid Oxide Fuel Cells (SOFCs), due to its excellent mechanical and thermodynamic stability and considerable proton conductivity. Developing novel materials via atomistic level simulation techniques is cost-effective and highly-efficient. In this abstract, we demonstrated the thermodynamic and kinetic database constructed for A and B-site doped BaHfO3, i.e. a novel proton-conducting perovskite system. We took advantage of ab-initio density functional theory calculations, transition state and diffusion theory, along with statistical thermodynamics. We successfully computed the key physical quantities relevant in hydration, proton conduction, and degradation process. The data obtained was analyzed through a data-science approach, by correlating computed quantities with intrinsic dopant properties, e.g. ionic radius, electro-negativity, etc. In the end, quantitative descriptors within fitting equations can be established for predicting unexplored dopants.

This set of methods, including data-analytics, can be viewed as a standard way in constructing thermodynamic and kinetic database for other solid state ionic materials.

Figure 1
Nanoconfinement for Multi-Step Reaction Cascade System
Authors: Chavan Kanchan Suklal , Calabrese Barton Scott
Published: February 2020

Multi-step reaction can be carried out efficiently using integrated catalytic system for the manufacture of advanced materials, energy conversion and harvesting, and human-machine interfaces. Nature has shown effective way to carry out multi-step reaction through substrate channeling.1 Molecular tunneling2 and electrostatic guidance3 mechanisms of substrate channeling has been studied extensively in literature and has proven their potential for efficient substrate channeling with minimum intermediate diffusional loss.

Molecular tunneling restricts intermediate diffusion through tunnel wall between active sites, whereas, electrostatic guidance restricts intermediate through surface interaction. Incorporating these two mechanisms into multi-step reaction system can lead to innovative integrated catalytic system.

In this work, continuum modeling has been performed on geometry consist of tunnel and two active sites confined within. Tunnel surface is oppositely charged as of intermediate to introduce electrostatic interaction. System is governed by diffusion and migration as well as reaction kinetics. Effect of reaction kinetics and transport has been studied and defined as Damköhler number. Channeling efficiency is defined by product yield at second active site relative to intermediate production at first active site. Effect of geometrical parameter such as distance between active site (d), distance between active site and bulk (le
), tunnel diameter(h) as well as ionic strength (I) of the system has been studied. Minimizing intermediate access to the bulk and increasing driving force for the intermediate to transport to active site is required for efficient channeling.

References:

I. Wheeldon, S. D. Minteer, S. Banta, S. C. Barton, P. Atanassov and M. Sigman, "Substrate channelling as an approach to cascade reactions", Nat. Chem., 8, 299–309 (2016). doi:10.1038/nchem.2459.

E. W. Miles, S. Rhee and D. R. Davies, "The molecular basis of substrate channeling", J. Biol. Chem., 274, 12193–12196 (1999). doi:10.1074/jbc.274.18.12193.

A. H. Elcock, G. A. Huber and J. Andrew McCammon, "Electrostatic channeling of substrates between enzyme active sites: Comparison of simulation and experiment", Biochemistry, 36, 16049–16058 (1997). doi:10.1021/bi971709u.
Review of Capacity Fade Models for Lithium-Ion Batteries - Numerical Implications of SEI Layer Growth
Authors: Fan Mengdi , Lee Seong Beom , Pathak Manan , Qi Yanbo , Chen Jerry , Subramanian Venkat R.
Published: February 2020

Lithium-ion battery applications, such as EVs and PHEVs, require long battery life. However, capacity fade always occurs due to unwanted side reactions including electrolyte oxidation at the positive electrode, lithium deposition at the negative electrode, electrolyte decomposition processes, and formation of the Solid-Electrolyte Interphase (SEI) layer1. To model the capacity fade, different models have been proposed in the literature2-4.

In this presentation, we model the capacity fade by assuming the SEI layer formation to be the dominant mechanism. We address how to efficiently simulate SEI layer growth and modify the simulation approach for the solid phase equations if needed. Even within SEI layer models, several different expressions have been used in many papers5-8. In most cases, the solid particles are assumed to be spherical, and the intercalation process is modeled using Fick’s law of diffusion in the radial direction. For solving the solid-phase diffusion in the radial-dimension, many efficient methods to reformulate and simulate have been proposed in the past9-12.

The SEI forming side reaction with the Single Particle Model (SPM) is first studied. The partial differential equation of the SPM is discretized using the finite difference method in radial direction and solved in time using the numerical method of lines approach. An assumption of a parabolic profile in the radial direction is another efficient approximation9-12. After this, we combine the SEI layer model with the pseudo two-dimensional model to predict the performance of the battery.

Acknowledgements

The authors thank the Department of Energy (DOE) for providing partial financial support for this work, through the Advanced Research Projects Agency (ARPA-E) award number DE-AR0000275.

References

P. Arora, R. E. White, M. Doyle, J. Electrochem. Soc., 145, 3647-3667 (1998).

J. Park, J. H. Seo, G. Plett, W. Lu, A. M. Sastry, Electrochem. Solid-State Lett., 14, A14 (2011).

Y. Dai, L. Cai, R. E. White, J. Electrochem. Soc., 160, A182 (2013).

X. Lin, J. Park, L. Liu, Y. Lee, A. M. Sastry, J. Electrochem. Soc., 160 (10) A1701-A1710 (2013).

M. Safari, M. Morcrette, A. Teyssot, and C. Delacourt, J. Electrochem. Soc., 156(3), A145-A153 (2009).

P. Ramadass, B. S. Haran, P. M. Gomadam, R. H. White, and B. N. Popov, J. Electrochem. Soc., 151, A196 (2004).

M. B. Pinson, M. Z. Bazant, J. Electrochem. Soc., 160 (2) A243-A250 (2013).

H. Ekström, G. Lindbergh, J. Electrochem. Soc., 162 (6) A1003-A1007 (2015).

C. Y. Wang, W. B. Gu, and B. Y. Liaw, J. Electrochem. Soc., 145, 3407 (1998).

W. B. Gu, C. Y. Wang, and B. Y. Liaw, J. Electrochem. Soc., 145, 3418 (1998).

P. W. C. Northrop, V. Ramadesigan, S. De and V. R. Subramanian, J. Electrochem. Soc., 158 (12) A1461-A1477 (2011).

V. Boovaragavan, V. Ramadesigan, and V. R. Subramanian, J. Electrochem. Soc.,
157 (7) A854-A860 (2010).
Physical-Statistical Modeling and Analyses of Catalyst Degradation in PEM Fuel Cells
Authors: Baroody Heather Ann , Stolar Drew , Eikerling Michael Hermann
Published: February 2020

Platinum durability in the catalyst layers of polymer electrolyte fuel cells is a major challenge that delays the full commercialization of fuel cell vehicles. This work presents a physical-statistical model of platinum degradation. The modeling framework of the Pt degradation model encompasses the main processes at the particle level, namely catalyst dissolution, redeposition, coagulation, and detachment, and it accounts for the effluence of Pt ions into the polymer electrolyte membrane. Data sets analyzed with the model encompass

information on changes in electrochemically active surface area, particle radius distribution, Pt mass distribution, and thickness of the catalyst layer. A systematic algorithm is developed to process experimental inputs and generate output information on kinetic rate parameters. The model-based data treatment proceeds in two stages: (i) statistical exploration of the complete parameter space using Monte Carlo techniques and (ii) an optimization routine to deconvolute contributions to degradation by different mechanisms and

determination of the pertinent set of parameters. Model outcomes contribute to fuel cell performance and lifetime evaluation, development of strategies for degradation mitigation, and calibration of efforts in design and fabrication of catalyst materials and catalyst layers.
Nonlinear Impedance Spectra Analysis of CO Poisoning on PEM Fuel Cell Performance
Authors: Pachimatla Rajesh , Srinivasan Ramanathan
Published: February 2020

In polymer electrolyte membrane (PEM) fuel cells, hydrogen is the preferred fuel with air or oxygen as oxidant. However, many a time, the presence of carbon monoxide (CO), even at low ppm levels, inhibits the hydrogen oxidation reaction [1, 2]. In this work, we describe nonlinear impedance spectra analysis (NLEIS) of CO poisoning in PEM fuel cells. In NLEIS method, large amplitude perturbations are employed and the resulting signal have significant higher harmonic components, which, if acquired, can provide additional information about the system under investigation. Here we illustrate a NLEIS methodology in which governing equations were solved without linearization, using numerical method. The response signal was subjected to fast Fourier transform (FFT) to extract magnitude and phase at fundamental and higher harmonics. In this study, linear adsorption model, in which a CO molecule occupies one adsorption site was employed to generate NLEIS data [3]. Figure 1 shows the concentration effect on NLEIS results, simulated under galvanostatic mode employing large (Iac = 200 mA) amplitude perturbation at Idc =200 mA.cm-2
. The results show that the CO poisoning effects are more easily distinguishable at higher harmonics, when compared to the response at fundamental frequency.

Key words: Nonlinear EIS, PEM fuel cell, CO poisoning, linear adsorption model

References:

[1]. L. Carrette, K.A. Friedrich and U. Stimming, Fuel Cells
1, 5 (2001)

[2]. J. Zhang, H. Wang, D. P. Wilkinson, D. Song, J. Shen and Z. S. Liu, J. Power Sources ,147, 58 (2005)

[3]. T. E. Springer, T. Rockward, T. A. Zawodzinski and S. Gottesfeld, J. Electrochem. Soc.

148, A11 (2001)

Figure 1
(Invited) Complementary III-V Heterojunction Tunnel FETs Monolithically Integrated on Silicon
Authors: Convertino Clarissa , Schmid Heinz , Czornomaz Lukas , Riel Heike , Sant Saurabh , Schenk Andreas , Moselund Kirsten
Published: February 2020

Conventional scaling is hampered by the inability to further reduce operating voltages. The main reason for this is the limitation on the subthreshold swing of a MOSFET which determines the abruptness of the on-off transition. This is an inherent limitation of the MOSFET device physics and cannot be remedied by the introduction of novel materials or architectures, but remains an underlying physical limitation. A number of devices have been proposed to overcome this limitation, of those, the most promising in a CMOS setting remains the tunnel FET (TFET). Within the past decade, initial euphoria regarding TFET properties were replaced by more realistic hopes as more thorough simulations brought a deeper understanding of device limitations and opportunities. In this respect it became clear that careful device design and a stringent control of defects is required to realize the promise of TFETs experimentally. Very recently experimental tunnel FETs showing sub-thermionic swing over a significant current range were demonstrated, showing that it is possible to beat CMOS performance. However, technologically heterojunction TFETs are much more complex than a silicon MOSFET. Our focus has been on dense monolithic integration of complementary III-V heterojunction TFETs on silicon, which may eventually evolve into a hybrid technology platform. In this talk we will give a general overview of the development of TFETs, discuss the challenges and opportunities both at the individual device level as well as in terms of technology development.
Investigating the Elimination of Oxygen Vacancy and Nitrogen Gap in Hafnium Oxide Films Induced By Different Nitridation Process
Authors: Lu Ying-Hsin , Chen Min-Chen , Chang Ting-Chang , Lin Yu-Shan , Liu Xi-Wen
Published: February 2020

This study investigates the elimination of oxygen vacancy and nitrogen gap in hafnium oxide films induced by different nitridation process. Based on previous studies, the oxygen vacancy in hafnium oxide could be passivated by the diffusion nitrogen, thus, enhancing the performance and reliability of n-MOSFET. On the other hand, as for p-MOSFET device, the nitrogen diffuses into the channel interface to generate interface defects, causing S.S. degradation to the device. However, in the HfO2 thin film, the nitrogen interstitial defect will be generated when the concentration of nitrogen is higher. These interstitial defects are located in HfO2 with the energy level below the mid-gap. Therefore, the holes can be trapped into the nitrogen interstitial defects while they transport from the channel to the gate. This work investigates the reduction of nitridation time and annealing time to device to further verify the hafnium oxide layer of nitrogen and oxygen vacancies bonding to reduce nitrogen interface defects. The influence of different nitrogen concentration and annealing time to device performance and reliability are also investigated.
Improvement of Line Width Roughness and Line Edge Roughness for Ultrascaled Finfet Technologies
Authors: Jiang Xin , Zhang Haiyang
Published: February 2020

As FinFET feature size scaling down, the fins are against more critical challenges by using either self-aligned double patterning (SADP) or self-aligned quadruple patterning (SAQP) method. Wiggling, line width roughness (LWR) and line edge roughness (LER) play more crucial roles at sub-14nm technology and beyond. Traditionally, post plasma treatment methods for photoresist are largely investigated to improve the LWR and LER. For the SADP and SAQP technology, pattern transferring is also another critical feature of dry etch process for pattern line wiggling. In this paper, both plasma photoresist treatment and dry etch process optimization are studied for improving LWR and LER.