bluuebunny/crossref_metadata_2025 huggingface dataset:
(Digital Presentation) Three-Dimensional Pore-Scale Modelling of NMC Cathodes Using Multi-Resolution FIB-SEM Images
Authors: Ghadban Mohamad , Sabharwal Mayank , Li Xiaolin , Goode Angela E. , Smith Maciah , Murphy Carmen , Secanell Marc
Published: November 2022

Lithium-ion battery (LIB) cathodes are porous electrodes made of active material (AM) that stores lithium, a composite of carbon additives and polymeric binder (CBD) that facilitates electron transport and ensures the mechanical integrity of the electrode, and electrolyte-filled pore space that facilitates lithium-ion transport [1]. The volume fraction and morphology of the different constituents at the microscale necessarily determine transport properties and influence the measurable performance [2]. In this work, the impact of NMC electrode microstructure on the effective transport properties is studied using FIB-SEM-based three-dimensional (3D) particle-resolved microscale simulations. The effect of AM and CBD bulk electronic conductivity on the effective electronic conductivity is first studied and used to highlight that the impact of the AM bulk conductivity is negligible compared to that of the CBD. Next, the impact of CBD volume fraction, in isolation from its morphology, is studied using morphological operations by eroding and dilating the CBD phase in the FIB-SEM images and analyzing its impact on the effective conductivity using multiple 3D reconstructions. Increasing the CBD volume fraction results in a nonlinear increase in the effective electronic conductivity. To study the effect of CBD morphology, two stochastic CBD reconstruction techniques are proposed. The first method places new CBD voxels preferentially next to existing CBD voxels, and the second method deposits the CBD randomly in the pore space. The effective electronic conductivity for microstructures containing stochastic CBD morphologies is calculated and compared to that evaluated for microstructures with eroded and dilated CBD. The CBD generated stochastically results in a predicted higher effective electronic conductivity primarily due to a lower CBD tortuosity when compared to the CBD generated with morphological operations. Finally, the impact of CBD porosity on electrode tortuosity is studied by estimating the pore-phase tortuosity considering a solid and a porous CBD. The diffusivity of the porous CBD is estimated using multi-resolution FIB-SEM images. Results show that not accounting for the CBD porosity increases the electrode tortuosity by a factor of up to three at low electrode porosities.

References

[1] B. L. Trembacki, A. N. Mistry, D. R. Noble, M. E. Ferraro, P. P. Mukherjee, S. A. Roberts, Mesoscale analysis of conductive binder domain morphology in lithium-ion battery electrodes, Journal of The Electrochemical Society 165 (13) (2018) E725–E736

[2] Xu, Hongyi, et al. ‘Guiding the Design of Heterogeneous Electrode Microstructures for Li‐Ion Batteries: Microscopic Imaging, Predictive Modeling, and Machine Learning’. Advanced Energy Materials, vol. 11, no. 19, May 2021, p. 2003908. DOI.org (Crossref), https://doi.org/10.1002/aenm.202003908.

Figure 1
Model-Informed Si Electrode Design Considering Dynamic Pore-Closure and Stack Pressure Effects
Authors: Weddle Peter J , Verma Ankit , Colclasure Andrew M. , Smith Kandler
Published: November 2022

Silicon is novel Li-ion battery anode chemistry with exceptional theoretical energy densities. However, this alloying material has significant challenges with non-passivating solid-electrolyte interface (SEI) formation and significant chemo-mechanics issues. These issues have been studied extensively at the particle-level. However, extensive SEI formation and dynamic particle chemo-mechanics need to be accounted for when designing the overall electrode microstructure. For example, Si particle expansion can result in electrolyte pore-closure. During charging (Si lithiation), Si particles near the separator lithiate faster than Si near the current-collector. Thus, Si particles near the separator begin to expand faster and close-off electrolyte access to particles near the current collector. This heterogeneous through-plane lithiation then results in low overall electrode utilization, especially at high rates (i.e.,>1 C). The “choking off” effect is a result of a strong feedback between heterogeneous lithiation, Si expansion, and electrolyte pore closure.

To aid in Si electrode design and account for dynamic particle expansion/contraction, the standard pseudo-2D battery model is reformulated to account for finite-strain chemo-mechanics. This model explores the trade-offs between initial electrode porosity, electrode thickness, rate-capability, and external pressure. Additionally, the model implements simplified SEI growth dynamics to explore how SEI growth effects should be accounted for in electrode design.

The Figure illustrates polarization responses for a 1C charge for a Si/NMC532 cell. The different colors indicate different initial anode porosities. As shown in Figure a, the low initial porosity cases results in significant polarization, but additional gains after 50% initial porosity are significantly diminished. These results are shown for an external pressure of 15 psi. Figure b illustrates the cell thickness as a function of time. As illustrated, the lower porosity case starts at a shorter initial thickness. For all cases, the cell thickness increases as Si lithiates/expands. Figure c illustrates the anode porosity at the cut-off voltage as a function of anode thickness. As shown, the lower initial porosity case has significant pore-closure on the right-side at the separator interface. The higher initial porosity cases have increased anode lengths because the Si utilization is improved due to the reduced pore-closer effects. The graphic illustrates the main features of the reformulated pseudo-2D battery model.

Figure 1
A Review on Recent Advances in Mxenes for Energy Storage Application
Authors: Ruti Itum
Published: November 2022

MXenes can be used in batteries and supercapacitors for various purposes, including double-layered ion storage, redox-type ion storage, ion transfer regulation, steric hindrance, ion redistribution, electrocatalysts, electrodeposition substrates, etc. These materials perform a variety of functions in batteries and supercapacitors, including ion storage and redox-type ion storage, ion transfer regulation, steric hindrance, ion redistribution, electrocatalysts, electrodeposition substrates, and so on. This review discusses the effects of the MXene bulk and surface chemistries across various energy storage devices and clarify the correlations between their chemical properties and their use. Finally, we discuss the challenges and opportunities associated with MXene-based energy storage systems for future use.
Playing with Intramolecular and Intermolecular Electronic Effects in Lithiated Organic Electrode Materials
Authors: Bernard Lou , Jouhara Alia , Quarez Eric , Tran-Van Pierre , Renault Stéven , Poizot Philippe
Published: November 2022

Organic electrode materials offer obvious opportunities to promote cost‐effective and environmentally friendly rechargeable batteries. Over the last decade, tremendous progress has been made thanks to the use of molecular engineering focused on the tailoring of redox‐active organic moieties. However, the electrochemical performance of organic host structures relies also on the crystal packing like the inorganic counterparts, which calls for further efforts in terms of crystal chemistry to make a robust redox‐active organic center electrochemically efficient in the solid state. Following our ongoing research aiming at elaborating lithiated organic cathode materials, we will report on the impact of polymorphism on the electrochemical behavior of dilithium (2,3‐dilithium‐oxy)terephthalate vs. Li. Having isolated dilithium (3‐hydroxy‐2‐lithium‐oxy)terephthalate through an incomplete acid‐base neutralization reaction, its subsequent thermally induced decarboxylation mechanism led to the formation a new polymorph of dilithium (2,3‐dilithium‐oxy‐)terephthalate referred to as Li4‐o‐DHT (β‐phase). This new phase is able to operate at 3.1 V vs. Li+/Li, which corresponds to a positive potential shift of +250 mV compared to a polymorph formerly reported and referred now to as Li4‐o‐DHT (α‐phase). This contribution will also be the occasion to underline the critical role of the crystal arrangement in organic electrodes by mitigating intramolecular electronic effects by through‐space charge modulation. This finding paves the way for further researches by smartly tuning electronic effects at molecular level as well as in the solid state or in other words, by combining molecular engineering (organic chemistry) and crystal design (materials science).
The Correlation of Strain and Catalytic Activity of Au, Pt, and Pd on Graphene
Authors: Drexler Matthew N , Alamgir Faisal M.
Published: November 2022

The catalytic activity of transition metals is highly influenced by the shape of their d-bands. This can be influenced by adjacent materials through two mechanisms: the strain effect, where the degree of orbital overlap affects their electronic structure; and the ligand effect, where the orbital overlap of two different atoms convolves their electronic structures, altering the energy distribution of their bands and transferring charge between them. Benefits derived from manipulating these effects are usually obtained through alloying or the use of core-shell structures, but a support substrate will produce these as well, although they are more difficult to attribute to a substrate as these effects only have an effective range of a few atoms. In a previous study looking at a few monolayer equivalents of Pt on graphene, it was observed that the two effects dominated at different amounts of deposition, with detrimental ligand effects dominating at less than three monolayer equivalents of deposition while beneficial strain effects dominated at higher deposition amounts. Normally, these effects are inseparable, but these effects could be decoupled due to the way that Pt bonds with graphene allowing it to alleviate strain at low dimensions. This seeks to expand on that study by characterizing the interactions between Au and Pd in addition to Pt by depositing up to five monolayer equivalents of each metal and observing how the structure and catalytic activity of each change with the increasing self-influence of each metal.

The average atomic strain in Au and Pt were measured using extended X-ray absorption fine structure analysis, while the atomic structure of Pd was observed through scanning transmission electron microscopy. It was found that Pt and Au both show a compressive strain while graphene imposes a tensile strain on Pd, but this strain gradually lessened with deposition amount for Au while it remained relatively constant for Pt and Pd. This demonstrated that the catalysts were highly influenced by their strain as their catalytic activity showed similar trends, with the Pt and Pd catalysts being relatively invariant in catalytic activity over the deposition range observed while the Au samples showed a gradual decline in activity with deposition amount. In comparison to reference samples, all three catalysts are improved by their interactions with graphene, which is supported by computational analysis, but the nature of its influence is different on each.
Electrodeposition of Lithium Manganese Oxide Cathodes for Lithium-Ion Batteries
Authors: Manjum Marjanul , Jalilvand Golareh , Mustain William Earl
Published: November 2022

Lithium manganese oxides (LMOs) have drawn significant interest as cathode materials for lithium (Li)-ion batteries due to their high thermal stability, high energy density, and a longer cycle life at a lower cost than lithium cobalt oxides. A significant amount of research has been conducted to prepare cathode materials for Li-ion batteries ex-situ and then to integrate them into electrodes after forming a slurry with the binder and deposition onto the current collector. An alternative pathway to achieve active LMO cathodes is to directly synthesize them on the current collector via electrodeposition (ED). Using ED not only could improve active material utilization and electrode mechanical properties, but it may also reduce the cost of electrode fabrication as well as provide a pathway for facile recycling of spent manganese from a number of applications (e.g. alkaline batteries).

To date, a few studies have reported the synthesis of LMOs by electrodeposition [1,2]. When doing this, the first step of the process is to deposit manganese oxide (s), MnxOy. Then, the oxide is lithiated to form the LMOs (i.e. LiMnxOy). Despite the fact that this process has been demonstrated, and active materials with reasonable capacity have been shown, it is presently unknown what LiMnxOy phase or phases are active. It is also not definitively known which MnxOy phase(s) is(are) involved in the transformation. To move the application of direct deposition of manganese oxide active phases closer to reality, a critical understanding of the solid-state chemistry for its conversion and energy storage is needed.

In this study, Mn oxides were electrochemically prepared by potentiostatic deposition on multiple substrates and treated by lithium hydroxide. After that, the heat treatment of the lithiated deposits gave a mixture of LMOs as the cathode materials on the substrate. This talk will discuss the likely reactions for the formation of LMOs as well as their chemistry during charge/discharge. The morphology and the elemental composition of LMOs will be shown by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The composition and presence of crystalline Mn oxides and LMOs will be clarified by X-ray diffraction. Lastly, results will be shown regarding the cycle performance of the electrochemically prepared LMOs as well as the crystalline phases present after charge-discharge.

References:

Quan, S. Ohguchi, M. Kawase, H. Tanimura, and N. Sonoyama, J. Power Sources, 244, 375 (2013).

Rana, M. Stan, R. Kloepsch, J. Li, G. Schumacher, E. Welter, I. Zizak, J. Banhart, and M. Winter, Adv. Energy Mater., 4, 1300998 (2014).
Electrodeposition of Equiatomic FePt Permanent Magnets from Non-Aqueous Electrolytes Based on Ethylene Glycol
Authors: Bernasconi Roberto , Nova Anna , Pane Vidal Salvador , Magagnin Luca
Published: November 2022

The highly ordered L10 hard-magnetic phase of the equiatomic FePt alloy is of significant interest for a great number of magnetic applications, ranging from the realization of micromagnets for integrated sensors to the deposition of thin layers for vertical recording media [1]. In this context, the development of wet deposition processes able to yield high-quality layers of FePt represents a topic of considerable industrial relevance. Even though several aqueous-based electrodeposition approaches have been developed for the manufacturing of FePt, most formulations evidenced substantial technological limitations, specifically connected to the use of water as solvent (hydrogen evolution, oxygen contamination of the deposit...).

From this point of view, non-aqueous electrolytes represent a promising alternative for the electrosynthesis of metallic layers. These alternative solvents are characterized by attractive applicative properties: they present wide electrochemical windows, are simple to prepare, formulated from relatively cheap components, almost unreactive with water and, in most cases, biodegradable. Thanks to these properties, they have been widely employed for the electrodeposition of metals [2], alloys [3] or composites [4].

The present work describes the deposition of FePt from a non-aqueous electrolyte based on ethylene glycol, which presents potential advantages over water-based baths in terms of gas evolution reduction and purity improvement of the obtained coatings. Deposition is carried out using Fe(III) and Pt(IV) as precursors and ammonium chloride as additive to enhance the quality of the coatings and their compositional uniformity. In this way, equiatomic FePt thin films characterized by a good morphology are easily obtained. These layers are subsequently characterized to assess their morphology, phase composition and magnetic properties. After annealing at 600 °C, the microstructure changes and the disordered face centered cubic phase present in the as-plated alloy evolves into the highly magneto-crystalline anisotropic L10 phase. As a consequence, the coercivity of the layers reaches values in excess of 10 kOe.

[1] Lodder et al.; Encyclopedia of Materials: Science and Technology, pp. 1-10 (2005)

[2] Abbott et al.; Phys. Chem. Chem. Phys. 8, 4265-4279 (2006)

[3] Bernasconi et al.; J. Phys. Chem. B 124(47), 10739-10751 (2020)

[4] Rosoiu et al.; Metals 10(11), 1455 (2020)
(Digital Presentation) Electrodeposition of Thin Films of Femn Alloys for Biodegradable Scaffolds Fabrication
Authors: D Gabbardo Aline , Costa Isolda , Ferreira Jane Zoppas
Published: November 2022

Biodegradable metallic scaffolds are interesting biomaterials for applications in temporary implants for bone regeneration because of their good mechanical properties. In addition, the need for a second surgery to remove the implant is reduced if biodegradable metals are used. Fe has adequate mechanical properties for scaffolds manufacture and suitable biocompatibility. However, Fe shows slow biodegradation rates for the application and, therefore, different approaches have been developed such as the development of alloys or by reducing the thickness of the Fe strut in the scaffold. FeMn alloys are considered ideal materials, as they are not ferromagnetic. In addition, additive manufacturing technologies (3D printing) are considered appropriate to manufacture these scaffolds due to the ability to obtain complicated geometries and customized parts for a specific bone injury site. Electrodeposition is also an interesting technique because it allows the deposition of thinner strut walls of Fe (or alloys) with high purity, in addition to providing a good surface finishing. The aim of the first part of this work is to electrodeposit thin films of FeMn alloys and to evaluate its microstructure and mechanical properties. The thin films were electrodeposited potentiostatically from sulfate electrolytes with different concentrations of FeSO4 and MnSO4. The effect of deaeration, substrate material and electrodeposition potential were evaluated. The microstructure of the electrodeposited films was characterized by SEM/EDX and XRD. The surface finishing was evaluated by AFM and the mechanical properties by microhardness measurements.
High Purity Pd Nanofilm Deposition Via Cu Incorporation Control in Slrr Process
Authors: Kim SooJin , Seo Jinmyeong , Yoon Sanghwa , Yoo Bongyoung
Published: November 2022

Department of Materials Science & Chemical Engineering, Hanyang University, Ansan 15588, Korea

*byyoo@hanyang.ac.kr

ABSTRACT

The deposition of palladium has been considered in many industrial applications and in fundamental science because of the high catalytic activities. Careful control of smooth and continuous Pd film less than 1nm thickness is critical for achieving highly active catalysts. Furthermore, perspective of cost-effective view, minimum usage of Pd is essential for catalyst while showing maximum activity for catalyst due to its high cost.

Electrochemical-atomic layer deposition (E-ALD), can achieve the growth of atomic level of metal film under room temperature and simple condition. E- ALD protocol proceeds using surface limited redox replacement (SLRR). SLRR involves 2 step. First, Au substrate is covered with Cu monolayer, the result of underpotential deposition of Cu (sacrificial element). Underpotential deposition (UPD) is the deposition occurs at more positive potential than equilibrium potential which the potential where deposition actually strats and UPD can limit Cu deposition by atomic layer. Second, Cu atomic layer is replaced by more noble metal (Pd) by galvanic displacement without applying potential. In one cell approach, the concentration ratio of sacrificial metal and noble metal and potential set is carefully set in order to deposit pure noble metal layer. Therefore, precise control of potential and metal concentration is important to execute successful SLRR which prevent Cu incorporation and Pd overpotential deposition upon Cu UPD formation.

In this study, pure Pd nanofilm was formed on Au substrate using Cu sacrificial metal by SLRR protocol. Effort of minimizing Cu incorporation was conducted by controlling Pd ion concentration, potential , open circuit potential condition and adding additive. Pd film was characterized by XPS, AFM and open circuit potential was analyzed by potentiostat. By controlling Pd deposition condition, pure Pd film was successfully formed.

KEYWORDS

Palladium, one-cell, nanofilm, SLRR, Cu UPD
Tailored Bismuth Nanowires for Size-Dependent Transport Studies
Authors: Wagner Michael Florian Peter , Voss Kay-Obbe , Trautmann Christina , Toimil Molares Maria Eugenia
Published: November 2022

Bismuth nanowires are excellent model systems to investigate the interplay of various size-dependent transport phenomena relevant for applications in thermoelectrics, spintronics or catalytics.

Due to the large Fermi wavelength (lFermi~40 nm) and mean free paths of charge carriers (le and lph ~100 nm) in bismuth at room temperature, the influence of size-effects on the transport properties can be observed on nanowires of rather large diameters. Furthermore, these properties are also influenced by the fact that bismuth belongs to the class of topological insulator materials that exhibit special charge carrier transport on the material surface linked to topological states. To better understand the transport behavior, it is of utmost importance to control the nanowire properties like surface-to-volume ratio, wire diameter and wire morphology, crystal structure, material composition and, in case of nanowire assemblies, their relative alignment to one another.

We present the synthesis of parallel and interconnected assemblies of bismuth nanowires with both cylindrical and conical geometry, and sizes ranging between 50 and 3500 nm. The wires are produced by electrodeposition in polymeric etched ion-track templates applying pulsed plating and an aqueous electrolyte of bismuth chloride. The electrodeposition process as well temperature-dependent Seebeck coefficient and electrical resistance measurements as a function of nanowire size and geometry will be discussed.

Figure 1
Electrodeposition of Plasmonic Nanostructures
Authors: Vasiljevic Natasa , Cruz San Martin Vinicius , Sarua Andrei
Published: November 2022

Electrochemical control and the use of electrodeposition in the design of dynamic plasmonics have attracted much attention in recent years.1 Development of dynamic plasmonic metamaterials is attractive for many applications such as molecular sensing and analysis, environmental monitoring, photo-catalysis, colour changing displays and electrochromic devices such as 'smart' windows. Electrodeposition is one of the most attractive ways to create and reversibly transform nanostructures' shape, size and chemical composition.2,3

Plasmonics is related to the localised surface excitations of electrons in metal nanostructures due to strong interactions with light. The resulted electric field enhancement due to the surface plasmons can be used to manipulate light–matter. Nanostructured Ag and Au are classic plasmonic materials. While silver is a metal that exhibits many advantages over gold, such as higher extinction coefficients in the blue and UV region of the EM spectrum, sharper extinction bands and extremely high field enhancements, its employment is hindered by low chemical stability. The most recent theoretical analysis suggests that Au-Ag derived nanostructures with controlled geometry, composition, and distribution can create new interesting optical phenomena.4 By developing Au-Ag based nanostructures, we can then benefit from combining optical properties of Au and Ag and, at the same time, improve the chemical stability of silver.

We investigated the electrodeposition of Au and Ag-based arrays of ordered and random nano-particles on indium tin oxide substrates from different solutions and studied their optical properties. We demonstrated that varying the electrodeposition parameters led to changes in both the resonance wavelength and the strength of resonance linked to the structural characteristics (size and shape) and the chemical composition of the deposited particles. Exploration of the dynamic reversible changes via electrodeposition will be presented.

References:

Y. Jin, L. Zhou, J. Liang, and J. Zhu, Adv. Photon., 3(4), 044002 (2021).

G. Wang, X. Chen, S. Liu, C. Wong, S. Chu, ACS Nano, 10 (2), 1788–1794, (2016)

C. J. Barile, D. J. Slotcavage, J. Hou, M. T. Strand, T. S. Hernandez, M. D. McGehee, Joule 1 (1), 133-145 (2017)

G. Guisbiers, R. Mendoza-Cruz, L. Bazan-Diaz, J. J. Velazquez-Salazar, R. Mendoza-Perez, J. A. Robledo-Torres, J. L. Rodriguez-Lopez, J. M. Montejano-Carrizales, R. L. Whetten, Jose-Yacaman, M. ACS Nano, 10(1), 188-198, (2016)
Electrochemical Epitaxy: Perspective and Applications
Authors: Brankovic Stanko
Published: November 2022

Properties of heteroepitaxial thin films are often dependent on the method and conditions for deposition[1]. In that respect, the electrochemical growth represents energetically different approach as compared to conventional vacuum deposition methods. It offers unique advantages, which can be exploited to get high quality ultra-thin films. The obvious one is that process occurs at an ambient temperature, which allows growth of heteroepitaxial metal overlayers while preserving the integrity of the interface. In recent years, significant progress has been made in controlling the thin film growth modes[2],[3],[4]. Various approaches to manipulate growth kinetics and enhance the evolution of atomically flat epitaxial overlayers were discovered[5],[6],[7]. Some of these findings were successfully implemented in electrochemical epitaxial growth resulting in development of deposition protocols such as Defect Mediated Growth (DMG)[8],[9], Surfactant Mediated Growth (SMG)[10] and growth via Surface Limited Redox Replacement (SLRR)[11],[12] with its sub-derivatives such as SEBALD, ECALD, ECALE, E-less ALD. These methods are used extensively by practitioners in different areas to synthesize monolayer or nanocluster catalysts and ultra-thin films with different compositions and applications.

In this talk, we will review current perspective and progress on electrochemical epitaxial growth. Discussion will focus on fundamental and practical details of the relevant phenomena about UPD, SMG, DMG, SLRR and E-less ALD using examples and challenges that are facing researchers in these areas. If time allowed, some out of the box idea will be posted opening podium for discussion.

References

[1]. D. L. Smith, Thin-Film Deposition, McGraw-Hill, New York (1997).

[2]. Z. Zhang and M.G. Lagally, Science,
276, 377 (1997).

[3]. J. A. Venables, G. D. Spiller, M. Hanbucken, Rep. Prog. Phys., 47, 339 (1984).

[4]. A. Pimpinelli and J. Villain, Physics of Crystal Growth, p. 181, Cambridge University Press, NY (2007).

[5]. G. Rosenfeld, R. Servaty, C. Teichert, B. Poeselma and G. Comsa, Phys. Rev. Lett.,
71, 895 (1993).

[6]. J. Camarero, J. Ferron, V. Cros, L.Gomez, A.L. Vazquez de Parga, J.M. Gallego, J.E. Prieto, J.J. de Miguel and R. Miranda, Phys. Rev. Lett.,
81, 850 (1998).

[7]. Z. Zhang and M. G. Lagally, Phys. Rev. Lett.,
72, 693 (1994).

[8]. K. Sieradzki, S.R. Brankovic and N. Dimitrov, Science,
284, 138 (1999).

[9]. S. Hwang, I. Oh and J. Kwak, J. Amer. Chem. Soc.,
123, 7176 (2001).

[10]. S.R. Brankovic, N. Dimitrov and K. Sieradzki, Electrochem. Solid-State Lett.,
2, 443 (1999).

[11]. S.R. Brankovic, J.X. Wang and R. R. Adzic, Surf. Sci., 474, L173 (2001).

[12]. Nikolay Dimitrov, Electrochim. Acta, 209, 599 (2016).
Perspectives for Deep Eutectic Solvents and Ionic Liquid Analogues in Metal Electroplating
Authors: Ryder Karl Scott , Lei Chunhong , Lucio Anthony J , Viles Stephen
Published: November 2022

Here we will specifically describe the opportunities and perspectives offered by non-aqueous so-called deep eutectic solvents (DES) and ionic liquid analogues (ILA) in the materials finishing and metal electroplating industries. We will describe a range of plating and dissolution processes from anti-corrosion coatings to new battery technologies. Details will be presented of the plating and characterisation techniques using some novel in-situ methods. These include electrochemical processing and characterisation as well as a number of cutting-edge surface methodologies including acoustic resonance methods, ESR, EXAFS, atomic force microscopy, neutron scattering techniques and magnetic resonance imaging.

We will describe a number of case-studies including electrolytic deposition of nickel, alloys such as Ni/Zn, and galvanic methods associated with Au and Ag coatings for the electronics industry. 1, 2, 3 In all these studies we have focused on a combination of fundamental chemical, electrochemical, structural and spectroscopic studies, maintaining close links with industrial partners through collaboration and scale-up trials.

We will include very recent updates and future prospects on the use of ILA's in energy storage vectors such as Al secondary batteries. We will describe the advantages and drawbacks of DES and ILA systems in terms of functionality, sustainability and economic cost.

References:

1) Chunhong Lei, Henrik Skouby, Rod Kellner, Emma Goosey, Martin Goosey, Jon Sellars, David Elliot and Karl S. Ryder, Trans IMF, 2022, 100, 2, 63

2) Andrew D. Ballantyne, Robert Barker, Robert M. Dalgliesh, Virginia C. Ferreira, A. Robert Hillman, Emma J. R. Palin, Rachel Sapstead, Emma L. Smith, Nina-Juliane Steinke and Karl S. Ryder, J. Electroanal. Chem., 2018, 819, 511P.

3) Andrew P. Abbott , Andrew Ballantyne, Robert C. Harris, Jamil A. Juma and Karl S. Ryder, Electrochimica Acta, 2015, 176, 718
Efficient Electrochemical Hydrogenation of Unsaturated Organics Using Noble-Metal-Free Pentlandite Catalysts
Authors: Siegmund Daniel , Pellumbi Kevinjeorjios , Wickert Leon , Kleinhaus Julian Tobias , Wolf Jonas , junge Puring Kai , Apfel Ulf-Peter
Published: November 2022

Electrocatalytic hydrogenation reactions (ECH) increasingly emerge as promising methods in the reductive production of base- and fine-chemicals. When driven by renewable energies, it constitutes a sustainable option circumventing the need for gaseous hydrogen, high pressure conditions as well as stoichiometric reducing agents which are associated with surplus waste formation. Furthermore, ECH processes can be operated under mild conditions close to room temperature and using green solvents such as water as proton source. Beyond these substantial advantages, an ideal ECH-process requires readily available, cheap and durable electrocatalysts capable of preplacing predominant noble metals to become industrially competitive. Along this line, much can be learned from natural enzymatic systems handling hydrogen. Inspired by the active sites of hydrogenases, which feature abundant transition metals in a sulfidic environment, we employed highly conductive 3d-metal chalcogenides of pentlandite type as highly efficient and cheap electrocatalysts for the ECH of unsaturated organic chemicals. Based on this inspiring compound class we demonstrate the relevant parameters to suppress the formation of parasitic hydrogen in favor for hydrogenations. Additionally, we outline the necessary interplay of material science as well as reactor engineering all the way from an initially promising catalytic material to a scalable sustainable electrochemical cell with industrial potential.

Figure 1
Challenges in Electrifying Chemical Manufacturing
Authors: Kenis Paul
Published: November 2022

Current processes used for the conversion of fossil fuel feedstock to fuels and other chemicals or intermediates as well as those used in chemical manufacturing in general tend to be highly carbon positive. These industries indeed are significant contributors to emission of excess carbon dioxide. Often this is the result of the use of fossil-fuel driven processes to yield the high temperatures and/or pressures needed to drive these processes, even in the presence of catalysts. Already, options to replace these energy-intense, carbon positive processes with less carbon positive processes is underway, for example the use of electricity driven processes.

This presentation will explore the status of electrolytic processes for chemical conversion at scale. Significant progress has been made in the electrochemical manufacturing of intermediates of key importance to the chemical industry (e.g., H2, CO, ethylene, ethanol, acetate, ...) using renewable feedstocks such as water and CO2. While electrocatalysts with reasonable activity and selectivity for these intermediates have been developed or are still being developed, several challenges still remain in the desired translation of these electrocatalytic conversion approaches to scalable electrochemical processes. This presentation will review issues and progress regarding a number aspects: (1) electrode durability, how to mitigate electrode degradation processes; (2) scalability of electrolysis cell designs; (3) opportunities for co-conversion, producing value-added products at both electrodes; (4) techno-economic and life cycle assessment of new electrochemical approaches to chemical manufacturing. Furthermore, the presentation will elaborate on associated challenges and needs, such as (i) the variability in composition of many renewable feedstocks (e.g., CO2 from different industrial plants, bio-derived substrates); and (ii) the need for new separations approaches, ideally renewable energy driven, able to purify the new/different product streams from the electrolytic chemical manufacturing processes.
(Invited) Long-Term Stability of Electrochemical Hydrogen Isotope Separation Using Graphene Layers
Authors: Silva Mayura Sankalpa , Creager Stephen
Published: November 2022

Hydrogen isotope separation is vital for multiple application areas including nuclear energy sectors and nuclear weapons, and is fundamentally interesting. Two-dimensional (2-D) materials such as monolayer graphene have been demonstrated in the past to selectively transport ions including hydrogen isotopes through them which provides a pathway for membrane-based isotope separation. Recent studies have shown that monolayer graphene and other 2-D materials embedded in membrane electrode assemblies (MEAs) prepared from proton exchange membranes (PEMs) such as Nafion® can selectively transport protons at rates up to 14 times higher than deuterons. The mechanism for this unusually high isotope selectivity is still under study and is thought to involve transport at localized defects sites with one or more chemical steps having a high kinetic isotope effect. The long-term stability of electrochemical hydrogen isotope separation using monolayer graphene-based membranes is crucial for the graphene to become a good sieving layer candidate for large-scale hydrogen isotope separation. The focus of this study is on the long-term stability of separating characteristics of graphene layers embedded in MEAs that actively pump protons and deuterons through them over an extended period of time. Initial results suggest that graphene embedded within Nafion sandwiches in their current form have a high isotope selectivity initially but that isotope selectivity can diminish as current is passed through the sandwich structures for extended time periods. Findings from chronoamperometry experiments performed on graphene-embedded MEAs while interchanging H2 and D2 gas feeds in symmetric electrochemical H/D pump cells, and potential factors affecting separation capability over long periods of time, will be discussed during the talk.
Electrochemical Desalination Using a Hybrid Redox-Flow Cell with a Ceramic Ion Conductor
Authors: Singh Siddhant , Tseng Flora , Lu Wei , Sakamoto Jeff , Kwabi David G.
Published: November 2022

Electrochemical desalination is a potentially energy-efficient strategy for distributed, small-scale purification of brackish sources, especially as compared to conventional processes that are reliant on heat or reverse osmosis. One promising subcategory of electrochemical desalination systems features a combination of sodium-intercalating electrodes and polymer-based anion-exchange membranes. Although desalination is technically feasible with this design, polymer-based ion-exchange membranes tend to have imperfect permselectivities and to be susceptible to water crossover between diluate and concentrate streams. These issues result in parasitic losses that increase the energetic cost of desalination.

We propose a hybrid flow cell design that features a redox-active electrolyte separated from a solid, anion-converting or anion-intercalating electrode with a solid ceramic ion-exchange membrane. By making use of a dense, ceramic membrane with a far greater selectivity for sodium ion conduction than analogous polymeric ion-exchange membranes, the parasitic issues described above are avoided. We discuss considerations that will impact the relationship among electrode and electrolyte properties, operational parameters (e.g. current density, concentration factor and water recovery percentage) and the energetic cost of desalination.
(Invited) Numerical Simulation Approaches for Understanding Transports Behavior inside Polymer Electrolyte Membrane Fuel Cells
Authors: Shimpalee Sirivatch
Published: November 2022

Augmentation of polymer electrolyte membrane (PEM) fuel cell (FC) performance at high current densities, particularly under automotive application, is important to improve the overall power density and to reduce the cost of PEMFC systems. Primarily, the fundamental non-linearity of the equations governing PEMFC performance on a three-dimensional model necessitates iterative solutions. As of now, mass transport over-potential is a major barrier to achieving high performance at a high current density. Experimental investigations of oxygen transport in particular are limited by an inability to resolve the water saturation-dependent properties. The alternative approach to understand and overcome transport resistances, predominantly inside the gas diffusion layer, is to use advanced numerical modeling.

Numerical simulation techniques using in PEMFC will be presented including conventional computational fluid dynamics and the meshless Lattice Boltzmann method (LBM) which is an alternative advanced modeling technique [1-14]. This approach can be applied to existing models to visualize the transports inside the structure of microscale geometries, such as: a gas diffusion layer (GDL), micro porous layer (MPL), and catalyst layer (CL). The study where the goal was to use these numerical approaches and directly predict the transports behavior across the length scale (macro-, meso-, micro-, and nano- scales) as shown in Figure 1. The understanding of local kinetic activity inside nanoscale CL implemented into the model will also be discussed. The achievement of this work can enhance the potential capability of a model-based investigation of transport physics inside PEMFC to find solution of designs and operational conditions especially for transport applications.

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Figure 1
Application of Pulsed Potential Waveform in Electrochemical Phosphate Recovery As Struvite from Wastewater
Authors: Sultana Ruhi , Greenlee Lauren F
Published: November 2022

Phosphate production is apprehended to peak as early as 2030, and post-peak, phosphate production, and thus food supply, will be limited by dwindling resources, strained economics, and reduced rock quality, with remaining resources expected to last 50-300 years. The limited supply of phosphate demands P conservation by changing the food production system, from fertilization to wastewater treatment. Stuvite (MgNH4PO4.6H2O) has been recognized as a high-value, slow-release, effective fertilizer that can be obtained from both solid (e.g., food, animal, and human waste) and liquid wastes (e.g., wastewater from industrial, municipal, and agricultural operations). The goal of our research is to recover struvite from wastewater using an alkaline electrochemical reactor with a magnesium alloy anode and a cathode constructed of standard catalysts for reducing water to hydrogen gas and hydroxide. Over time with successive reactor batches, the magnesium electrode used to generate magnesium cations in solution and precipitate struvite becomes severely fouled, which in turn increases energy demand and decrease struvite fertilizer recovery. A dynamic, pulsed voltage waveform, as opposed to a constant voltage, causes a stress-strain-like effect at the magnesium electrode surface, thereby preventing or reducing the amount of struvite precipitate that would attach to the electrode. In an aqueous solution of ammonium dihydrogen phosphate (NH4H2PO4, 10 mM) at neutral pH, a significant 50% increase in magnesium release is observed compared to constant voltage applications, resulting in a 30% increase in phosphate recovery. Studies of the recovered precipitate using X-ray diffraction and scanning electron microscopy (SEM) indicate the presence of struvite.
(Invited) Superconformal Cu Electrodeposition
Authors: Moffat Thomas P , Braun Trevor Michael , Raciti David , Josell Daniel
Published: November 2022

State-of-the-art manufacturing of semiconductor devices involves electrodeposition of copper interconnects The process depends on additives that affect the local deposition rate to yield void-free superconformal, or bottom–up filling of trenches and vias. Chemical process models describing the filling of high aspect ratio features, from nanometers (on-chip wiring) to micrometers (through-silicon-vias) to millimeters (printed circuit boards) are available. Nevertheless, much remains to be known about the molecular nature and competitive, co-adsorption dynamics of the additives and their impact on metal deposition. This lecture will detail experiments that reveal important aspects in the operation of additives used for superconformal film growth.
Unique Porous Structures Supported by Anodic Treatments in Liquid Ammonia (-50°C, Patm)
Authors: Bouttemy Muriel , Bechu Solene , Fregnaux Mathieu , Aureau Damien , Etcheberry Arnaud , Goncalves Anne-Marie
Published: November 2022

Since the first anodic porosification of semiconductors in the 1950s, numerous studies have reported a wide range of porous structures. The conditions used during the growth of pores can explained the shapes obtained but the formation mechanism and especially the influence of surface chemistry during porosification still raise many questions.

It is in such context that the contribution of liquid ammonia (-55°C) is crucial. Indeed, this remarkable non-aqueous solvent allows, on the one hand, to obtain novel porous structures on n-InP and, on the other hand, it allows for the first time a specific and original interfacial chemistry, governed by the chemistry of nitrogen.

In fact, in liquid ammonia, the dissolution of III-V semiconductors (GaAs, InP) is systematically done after a surface passivation step. This passivation step is particularly stable on InP and revealed the formation of a phosphazene type film (monolayer) resulting from the concomitant oxidation of the solvent and the semiconductor. The "multi-material" approach is a key factor, as it underlines the determinant role of the surface chemistry. In fact, at higher current densities, the porous structures of n-InP and n-GaAs show contrasting structures, which give an original behaviour compared to the aqueous medium. In order to determine the efficiency of the dissolution mechanism (at lower and higher current density), the quantity of indium (or gallium) salt will be quantified by Inductively coupled plasma optical emission spectroscopy analysis after ammonia evaporation.

Moreover, the remarkable reproducibility of the anodic behaviour allowed physico-chemical characterisations of the porous surface, supported by scanning electron microscopy and the variation of the interfacial potential, photoluminescence and X-ray photoelectron spectroscopy.

More specifically on n-InP, where an original structure was revealed, these analyses, during the early stages of porosification, led to the identification of a porosification mechanism in this solvent. Furthermore, at higher current densities, an amorphous film becomes thicker on the surface of the porous structure. Further porosification requires the permeability of this amorphous structure which would most probably result from the polymerisation of phosphazene since the presence of nitrogen could be clearly identified on the pore walls by Auger spectroscopy.
Assessing and Modifying Selective Transport for Nonaqueous Flow Battery Membranes
Authors: Koenig Gary , Mccormack Patrick , Geise Geoffrey
Published: November 2022

Membranes are a critical component for redox flow battery (RFB) systems. An ideal membrane must be stable in the RFB solvent and process environment, and to obtain desirable electrochemical performance must facilitate transport of the charge compensating ion while minimizing crossover of the dissolved electroactive species (e.g., redox shuttles). For more established aqueous RFB systems commercial membranes, such as sulfonated fluoropolymers, have been used to successfully facilitate development of RFB power stacks at industrial scales.

Recently, there has been interest in developing nonaqueous, or organic, RFB systems. A potential advantage of a nonaqueous RFB is the accessibility of higher voltages per cell, which would result in higher energy density for the RFB system. Membrane materials for nonaqueous RFBs are not well established, and thus the composition and processing for these membranes is an open area for further research.

In this talk, efforts towards the understanding and development of a nonaqueous RFB membrane material will be described. Assessment of the conductivity and crossover of the membrane material system will be discussed, as well as efforts to improve electrochemical properties and membrane stability. Initial results suggest that the interactions between the redox shuttles and the membrane are in many cases fundamentally very different for nonaqueous RFB membranes compared to aqueous RFB membranes, providing possibilities for different routes to design nonaqueous RFB membrane materials.
(Invited) Single Photon Detectors and Metrology
Authors: Buckley Sonia Mary , Stephens M , Lehman J.H.
Published: November 2022

For quantum applications, it is important to generate quantum states of light and detect them with extremely high efficiency. For many future applications, it also important to do this at scale. This presents many engineering and metrology challenges. Further, as the technology matures, these single photon detectors and sources may also have new exotic applications in fields other than quantum optics. In the first half of this talk, I will discuss our efforts to develop a scalable silicon-compatible light sources and waveguide-integrated superconducting detectors. In the second half of the talk, I will discuss some of the open challenges and opportunities in metrology of single photon detectors, and our work on developing accurate absolute power calibrations at the single photon level.