bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analyzing and Improving Performance of Anion Exchange Membrane Water Electrolysis
Authors: Green Zach , Wang Zhang , Shi Wenjuan , Yan Yushan , Xu Hui 
Published: February 2020

The utilization of renewable energy has substantially driven more attention into electrolysis technologies. In this scenario, water electrolysis device can be considered as a means of storing energy chemically rather than electronically like batteries. Furthermore, the establishment of H2@scale consortium has presented renewable H2 unprecedented opportunities toward multiple industrial and transport applications. However, current hydrogen production from electrolysis comprises only a small fraction of the global hydrogen market due to its high costs. Anion exchange membrane water electrolysis (AEMWE) enables to use non-precious metal catalyst as the catalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). However, the performance of state-of–the art AMWE is still inferior to its count part of proton exchange membrane water electrolysis (PEMWE).
The performance loss of AEMWE has been analyzed using different experiment design, which includes catalyst, ionomer, electrode configuration and operating conditions. In particular, commercial anion exchange membrane and ionomer have been compared with advanced materials by our multiple collaborators. Reversible fuel cell operations and addition of diluted salts or bases can also be used to pinpoint the sources of AEMWE performance loss. Based on the performance analysis, the following strategies can be used to improve the performance of AEMWE. First, anion exchange membrane and ionomer with high oxidative resistance will be adopted. These chemically and electrochemically stable materials will provided a better platform to test the OER or HER catalyst to enable alkaline membrane electrolysis operation. Second, an optimal interaction between the ionomer and the catalyst in the electrode will be established.
A General Method to Probe Oxygen Evolution Intermediates at Operating Conditions
Authors: Tao Huabing , Xu Yinghua , Huang Xiang , Chen Jingguang G , Liu Bin 
Published: February 2020

Observation of oxygen intermediates is the key to reveal the factors that limit the OER activity thus design of better catalysts. However, the liquid reaction environment makes it very challenging to probe oxygen intermediates at operating conditions. Although several in situ techniques are reported for the detection of intermediates on some catalysts, these methods apply only to certain circumstances. Therefore, so far, the most knowledge of oxygen intermediates is derived from theoretical simulations.
Herein, we developed a general and feasible method to probe oxygen intermediates. By employing alcohols as probing reagents, the oxygen intermediates can be readily captured. The method is so general and feasible that it can be adopted by every electrochemical laboratory. Besides the guidance for catalyst design, the chemical nature oxygen intermediates revealed from this work also open new opportunities for applying OER electrodes in other reactions.
(Invited) Overview on the European FCH Joint Undertaking Projects & Activities in PEM Fuel Cells and Electrolysis
Authors: Atanasiu Mirela , Tsimis Dionisis , Boillot Lionel 
Published: February 2020

The Fuel Cells and Hydrogen Joint Undertaking (FCH JU) was set up in 2008 to accelerate the development of fuel cells and hydrogen technologies in Europe towards commercialization from 2020 onwards. To reach this target the FCH JU brings together resources under a cohesive public-private partnership to ensure commercial focus, to match RTD activities to industry's needs and expectations and to scale-up and intensify links between the Industry Community and the Research Community. Research projects on PEM technology have had a central role within the program with significant funding allocated in order to advance the technology of both PEM fuel cells but also PEM electrolysers.
Regarding fuel cells, the primary focus has been the reduction of the Pt content within catalysts as well as on the improvement of power density. Additionally, significant funding has been dedicated on the improvement of durability as well as on the reduction of cost, particularly through improved manufacturing, while the next wave of research projects aims at the development of PGM free catalysts.
Similarly, for PEM electrolysis continuous support has been provided in order to scale up electrolysers from kW to MW, to improve performance and to reduce costs. This has contributed to the establishment of EU leadership on PEM electrolysis. The next steps are to focus on further improving performance by increasing the current density and operating pressure.
(Invited) Accelerating Optimization of Lithium Ion Battery Manufacturing Via Multiscale Computations
Authors: Franco Alejandro A. 
Published: February 2020

Electrochemical performance and lifetime of Lithium Ion Battery (LIB) composite electrodes strongly depend on their manufacturing parameters. Such parameters include the slurry formulation (i.e. the chemistry and amount of active material, carbon, binder and solvent), the temperature used to evaporate the solvent, the pressure applied during the electrode calendering and the time for the electrolyte impregnation. Within the perspective of developing more efficient LIBs at minimal R&D cost, it is important to develop robust tools able to predict the influence of manufacturing parameters on the electrodes mesostructure and the overall cell performance. In this keynote, i discuss the latest research progress in this sense within the ARTISTIC project, funded by the European Research Council (ERC). This project aims at developing and demonstrating a multiscale computational platform able to simulate the LIB manufacturing process and to predict optimal manufacturing parameters of LIBs responding to specific targets (energy density, etc.). Coarse Grained Molecular Dynamics, Discrete Element Method, Lattice Boltzmann and Continuum computational models are combined with deep learning algorithms to reach this objective. Examples of applications of this platform for NMC and graphite-based electrodes are discussed, in strong link with in house experimental characterizations. Physicochemical mechanisms leading to the composite electrode self-organization are discussed and guidelines towards the optimization of the multiple process steps are presented. At the end of the lecture, an experience using an in house Virtual Reality tool, to assess the manufacturing modeling results, will be proposed to the attendees.
[1] ARTISTIC project (European Research Council Consolidator Grant #772873): https://www.u-picardie.fr/erc-artistic/
[2] Franco, A. A., Rucci, A., Brandell, D., Frayret, C., Gaberscek, M., Jankowski, P., & Johansson, P. (2019). Boosting Rechargeable Batteries R&D by Multiscale Modeling: Myth or Reality?. Chemical Reviews. DOI: 10.1021/acs.chemrev.8b00239
[3] Rucci, A., Ngandjong, A. C., Primo, E., Maiza, M., & Franco, A.A., submitted (2019).
[4] Ngandjong, A. C., Rucci, A., Maiza, M., Shukla, G., Vazquez-Arenas, J., & Franco, A. A. (2017). Multiscale Simulation Platform Linking Lithium Ion Battery Electrode Fabrication Process with Performance at the Cell Level. The journal of physical chemistry letters, 8(23), 5966-5972.

Figure 1
Microscale Simulations of Drying and Calendering Processes to Manufacture Porous Electrodes
Authors: Nikpour Mojdeh , Barrett Nathan , Harrison Chelsea Ann , Wheeler Dean , Mazzeo Brian A 
Published: February 2020

Electrodes can suffer from inconsistencies in performance due to heterogeneity in particle arrangements. Manufacturing processes such as drying and calendering significantly alter the microstructure and introduce randomness, making it difficult to predict the final structure of the film, given process inputs. This has a crucial impact on the electrochemical and mechanical properties as well as the ultimate performance and lifetime of the battery [1]. The goal of this work is to analyze the behavior of electrode constituent materials during the drying and calendering steps using a new predictive model of microstructure.
We have developed a model to simulate the drying and calendering processes using the open-source Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) [2]. Within LAMMPS, we developed a customization of smoothed particle hydrodynamics (SPH), which solves the Navier-Stokes equations on particles representing both solid and liquid materials present in the electrode film.
We present here the development of the model and the resulting microstructure predictions for conventional Li-ion battery electrodes. Results are compared to experimental data where available, including microstructures determined from a new freeze-drying technique. Predicted properties such as effective conductivity and degree of heterogeneity can be used in more coarse-grained models to simulate cell performance.

References

[1]
M. Forouzan et al., J. Power Sources 312, 172-183 (2016).

[2] M. Nikpour et al., Meeting Abstracts, no. 3, pp. 268-268. The Electrochemical Society (2018).

Figure 1: Heterogeneous structure of the dried electrode: a) experiment, b) simulation; carbon-binder domain is grey, active material is yellow c) top-view of the dried film

Figure 1
Long-Life Ni-Rich NMC Cathodes with Heterogeneous Particle Structure Using Advanced High-Speed Synthesis Process
Authors: Chung Youngmin , Shin Youngho 
Published: February 2020

Layered Ni-rich cathode material, Li[NixMnyCo1−x−y]O2 (x ≥ 0.8), is one of the most prospective materials for rechargeable lithium-ion batteries (LIBs) due to its high capacity. However, significant challenges remain in order to improve capacity retention during cycling and thermal-abuse tolerance of this material. As one of the promising approaches to overcome barriers, a series of core-shell structured cathode materials with the overall bulk composition of LiNi0.8Mn0.1Co0.1O2 is produced via co-precipitation method where Ni-rich composition (LiNi0.9Mn0.05Co0.05O2) with higher capacity is particle core and Mn-rich composition with higher stability is particle surface.
It is challenging to design and implement heterogeneous structured particles with synergistic effects by combining the advantages of each composition. It is particularly important to develop a process of producing economically and quickly each type of these cathode particles, in which the Ni-rich composition and the Mn-rich composition change continuously or discretely from the particle core to the particle surface. To achieve this goal, a continuous rapid synthesis process for the production of heterogeneous structured cathodes was developed at ANL MERF based on an advanced Continuous Stirred Tank Reactor (CSTR) system and a Taylor Vortex Reactor (TVR) system.
A detailed description of the developed process to mass-produce heterogeneous structured materials economically and rapidly will be presented. The excellent physical and electrochemical properties of Ni-rich NMC cathodes with core-shell or core-gradient particle structures produced by this advanced process will be reported. The produced heterogeneous structured cathodes and commercially available normal NMC materials will be compared through analysis of coin half cell, pouch full cell, SEM, EDS, ICP-MS, DSC, EIS, and other advanced characterization techniques.
3D Architected Pyrolytic Carbon Electrodes with Multi-Scale Controlling Factors
Authors: Narita Kai , Citrin Michael A , Yang Heng , Xia Xiaoxing , Greer Julia R 
Published: February 2020

Engineering electrode architecture in rechargeable batteries has the potential to control transport trajectories of ions and electrons, which can significantly affect battery performance especially at high current rates and at high mass loadings. Many efforts have been dedicated to develop novel methods of engineering electrode architecture that include extrusion-based additive manufacturing and using sacrificial templates. These methods are limited in terms of producing resilient structures that can withstand the mechanical loads imposed during operation of the cell and are not yet capable of producing geometries that enable independent control of form factors in multi-scale ranges from micron to centimeters scales.
We developed a facile fabrication method of 3D architected carbon anodes using direct light processing (DLP) 3D printing of UV-curable resin and subsequent pyrolysis in an inert atmosphere. The specific architecture of these electrodes is fully controllable over every length scale: from local geometry (micrometer-scale) to control tortuosity and mass loading, as well as global geometry (centimeter-scale), to intergrade into any device geometries. In addition, the architected pyrolytic carbon electrode is free-standing and binder-free, enabled by the monolithic structure and great electrical conductivity of carbon.
To demonstrate the architected carbon electrode as an anode in lithium ion batteries, we fabricated 1 mm-thick 3D periodically architected carbon electrodes with simple cubic-like geometry and characterized its electrochemical performance by constructing a half-cell against a lithium metal counter electrode. Battery cycling of these electrodes using a coin cell showed reversible capacity of ~230 mAh/g (or 7 mAh/cm2) at a 16 mA/g (or 0.6 mA/cm2) and its capacity retained over 85 % until 100 cycles. Uniaxial compression tests revealed its high structural integrity, enabling the architecture to be maintained even after 300 cycles under pressure in a coin cell.
We further studied a correlation between electrode architecture design and battery performance by varying transport path of Li-ion in electrolyte independently from tortuosity of porous structure and Li-ion transport path in the electrode. In addition, key considerations to optimize electrode architecture will be discussed based on the comparison between stochastic structure of conventional slurry and designed electrode architecture under the same electrode material.
This multi-scale tunable fabrication method may give a new path not only to electrode design in conventional planner cells but also to a 3D interdigitated full battery.
Strategies for Tuning Optoelectronic Properties of TiO2 Nanomaterials for Solar Photovoltaic Studies
Authors: Delekar Sagar D. , Panda Dillip 
Published: February 2020

Third generation solar cells are mainly focusing on the use of nanomaterials as host components for solar-to-electrical conversions. Among the various nanomaterials, TiO2 is one of the most promising candidates used in solar devices due to their remarkable structural and opto-electrical properties. However, bare TiO2 nanomaterials have the various constraints in efficient solar energy conversions. In the present research endeavors, TiO2 nanomaterials have been modified with the different strategies such as dyad anchoring, dye-quantum dot sensitization, composites of carbon nanostructures with sensitizers, metal ion doping with sensitizers so as to tune its optoelectronic properties for efficient solar energy harvesting. In addition, the interconnectivity between the various components and their optoelectronic properties of modified TiO2 for solar energy conversions have been studied in detail.
In the dyad system, a supramolecular ruthenium(II)phthalocyanine··peryleneimide (RuPc···PI) has been anchored on the surfaces of TiO2 and thereafter these TiO2-dyad sensitized solar cells have assembled in a bottom-up fashion. Upon photo-irradiation at air-mass (AM) 1.5, the dyad-based solar devices convert solar light to electricity of 2.1%; which is higher than that of individual dyes. In next strategies, the synthesized CdS quantum dots (QDs) have connected electrostatically to the surfaces of TiO2 nanoparticles (NPs) and thereafter, this binary hybrid heterojunction is further self-assembled physically with N719 dye to form ternary TiO2 NPs-CdS QDs-N719 photoelectrodes. These co-sensitization devices reported the solar energy conversion efficiency (η) up to 2.35 %. In addition, anatase TiO2 NPs is anchored on the surface of functionalized carbon nanostructures (MWCNTs or RGO); which is further sensitized with Ru(II) dyes for solar devices having efficiency reached to 6.21%. In another modification, Cr(III) as well as Mo(VI) ions are inserted into TiO2 host lattice and then their composites with CNs are further sensitized for boosting the solar energy conversions and reached up to 7.69 % of efficiency.

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Stabilization of the Ionic Liquid – Electrode Interface from Large Nonpolar Groups in Ionic Liquids and Ionic Liquid Mixtures
Authors: Klein Jeffrey Michael , Squire Henry John , Gurkan Burcu 
Published: February 2020

Electrochemical capacitors, also called electrical double layer capacitors (EDLCs), can store energy in the interface between an electrode and an electrolyte. The interface where charge is stored influences more than simply EDLCs due to its presence at any charged surface. Conventional electrolytes, organic and aqueous based, form a well described electrode – electrolyte interface. However, conventional electrolytes are often limited in their application due to restrictions in thermal and electrochemical stability. Ionic liquids (ILs) are an emerging class of electrolytes with improved thermal and electrochemical stability compared to conventional electrolytes, however, the interface is poorly understood. Current understanding of the conventional systems cannot be completely transferred to ILs because they are not sufficiently described as point charges, and because ILs contain no solvent. Completing our understanding of the complex IL-electrode interface will greatly influence the efforts at designing task specific ILs for electrochemical devices. Here it is demonstrated that quaternary ammonium cations with large nonpolar substituent groups directly impact the anion density near the electrode at positive potentials. This work also addresses whether or not the unique IL-electrode interface is formed from a process which expels void space from the local environment, or by replacing “non-participating” neutral ion pairs with “participating” free ions.
Potential driven structuring of four neat ILs and two IL mixtures has been examined on a glassy carbon electrode. Potential dependent capacitance (differential capacitance), measured by electrochemical impedance spectroscopy, was used to examine the formed IL - glassy carbon interface. Differential capacitance curves were paired with physical measurements of viscosity, density, and conductivity as represented in a Walden plot. The Walden plot was used to estimate the extent to which the ions of the IL were dissociated. There appeared to be no trend between the extent of dissociation and the differential capacitance behavior. The absence of a trend between dissociation and differential capacitance suggests that the interface is not described by a simple model depending solely on the number of free ions in the interface. Instead, the interface depends more heavily on the intermolecular interactions between the constituent ions such as ion – ion repulsions and steric repulsions. It is shown in the differential capacitance curves that the ILs containing large non polar substituent groups have a more stable interface associated with the accumulation of anions. Stabilization of the interface holds even for mixtures of ILs where the minor component contains the large nonpolar group. Results from this work offer ways to selectively tune the ion density in the IL-electrode interface at specific electrode potentials.
Impact of Fe(III) on the Autocatalytic Processes of Corrosion of Stainless Steels in Concentrated Nitric Acid
Authors: Pellé Julien , Gwinner Benoit , Gruet Nathalie , Vivier Vincent 
Published: February 2020

This study takes place in the industrial context of the spent nuclear fuel reprocessing plants, in which hot and concentrated nitric acid is used in the process to dissolve nuclear fuel. This imply a high oxidative solution, due to nitric acid but also to species resulting from the dissolution of the fuel and/or the equipment. Especially where there is stagnant solution in which different nitrogenous species can accumulate, causing the autocatalytic reduction reactions of nitric acid. These mechanisms can be responsible of the corrosion processes of the equipment. Then, in order to have resistant equipment to this acidic and oxidizing medium, stainless steels were chosen. The purpose of this work is to investigate the corrosion mechanisms of stainless steels in such aggressive medium. Particularly, it was established that the presence of Fe(III) (corrosion product) accelerates the corrosion of stainless steels, due to the rise of the cathodic reactions [1, 2]. Thus, this work was focused on the specific impact of Fe(III) on the corrosion processes, including autocatalytic reduction reactions of nitric acid. Indeed, it was not clear if this acceleration of the cathodic processes was induced by a direct reduction of Fe(III) to Fe(II) at the surface of the material or if it was an indirect impact of Fe(III) by a catalyse of the nitric acid reduction process (involving reduced species of nitric acid such as HNO2, NO2 and NO) (Figure 1). In order to investigate this point, we coupled stationary electrochemical techniques (chronoamperometry, steady-state polarisation curves) or dynamic electrochemical techniques (electrochemical impedance spectroscopy) with local analytical techniques (RAMAN microspectroscopy, Scanning ElectroChemical Microscope). These studies were completed with the analysis of the gaseous products of the reactions (NO2 and NO production) by mass and IR spectroscopies. It was shown that the direct reduction of Fe(III) to Fe(II) at the surface of stainless steel has a minor contribution to the corrosion. Thus, the role of Fe(III) is essentially related to its catalytic effect on the nitric acid reduction reaction (Figure 1). From the different measurements performed, the following mechanism of interaction of Fe(III) with the nitric acid reduction was proposed (Figure 1) and the kinetic constants of some elementary steps were determined.
[1] Fauvet, P., et al. (2008). "Corrosion mechanisms of austenitic stainless steels in nitric media used in reprocessing plants." Journal of Nuclear Materials 375(1): 52.
[2] Fauvet, P. (2012). Corrosion issues in nuclear fuel reprocessing plants. Nuclear corrosion science and engineering. D. Feron, Woodhead Publishing. 22: 679-728.
[3] Lange, R., Phénomènes de couplage acier 304L – platinoïdes dans les milieux de dissolution des combustibles usés. 2012, UNIVERSITÉ PIERRE ET MARIE CURIE. p. 174.

Figure 1