bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrodeposition of Fe-Group Mutual Alloys for Efficient Electrochemical Water Oxidation
Authors: Xu Yin , Sun Yunkai , Zangari Giovanni
Published: May 2020

In this work, galvanostatic electrodeposition from an electrolyte without buffers was performed to generate thin films consisting of Ni, Fe and Co on various substrates. The self-limiting behavior was proven by electroplating at different durations, showing that the thickness was unchanged. The growth was self-limiting due to the pH increase, resulting in an outer layer composed of a compact hydroxide/oxyhydroxide. XPS depth profiles confirm the formation of the surface hydroxide/oxyhydroxide. Studies of nucleation dynamics show that these films nucleate slower if the alloy films include more elements. Ni-Co-Fe films deposited on Au were further investigated as electrochemical catalysts in 1M KOH solution for oxygen evolution. All the films exhibit reduced Tafel slopes (34.7 to 38.4 mV/dec) and small onset potentials (0.314 to 0.320 VRHE), implying an enhanced water oxidation kinetics. The optimum deposition time was found to be 1s in terms of the electrochemical catalytic properties, due to a lower thickness of the surface hydroxide/oxyhydroxide layer.
Anodic TiO2 Nanotube Layers As Scaffolds for Deposition of Functional Materials
Authors: Bawab Bilal , Krbal Milos , Prikryl Jan , Zazpe Raul , Sopha Hanna , Macak Jan M.
Published: May 2020

The self-organized 1D TiO2 nanotubular layers have attracted considerable scientific and technological interest over the past two decades, all motivated by a great performance in the range of applications including photo-catalysis, solar cells, hydrogen generation and biomedical uses [1,2]. The synthesis of these nanotubular layers has been carried out by a conventional electrochemical anodization of Ti sheet. Except the 1D character, these nanotubes possess unique features such as tunable dimensionality, structural flexibility, unidirectional electron transport through nanotube walls, chemical and mechanical stability and biocompatibility.

One of the major application targets of TiO2 nanotubes has been their utilization as scaffolds or templates for deposition of secondary materials towards new applications [3]. In particular, for the photoelectrochemical applications (e.g. photovoltaics) ordered nanostructures, such as self-organized TiO2 nanotubes, offer the advantage of directed charge transport and controlled phase separation between the donor and acceptor materials, unlike within randomly ordered mesoporous TiO2 supports.

Numerous techniques were utilized for this purpose, such as for example hydrothermal routes, electrodeposition or Atomic Layer Deposition (ALD) techniques. Electrodeposition is very powerful technique to deposit metals [4], oxides [5] or other rather complex materials (such as CuInSe2 [6]) within the nanotubes various by means of complete filling or decoration with. On the other hand, ALD can deposit the widest range of secondary materials within TiO2 nanotubes by means of homogenous coatings [7-10]. ALD is the only technique of choice to coat in particular high-aspect ratio nanotube layers. Overall, the deposited materials influence strongly photo-electrochemical properties of nanotube layers.

The presentation will be focused in detail on TiO2 nanotube layers of various aspect ratios filled, decorated or coated by various chalcogenide-based materials using electrodeposition and ALD. Experimental details and some very recent photo-electrochemical and structural characterizations of a new type of heterostructured photo-chemical cell will be presented and discussed.

References

1] J.M. Macak et al., Curr.
Opin. Solid State Mater. Sci.,
2007
,
1-2, 3-17.

2] K.Lee, A. Mazare, P. Schmuki, Chem.
Rev., 2014, 114, 9385-9454.

3] J.M. Macak, Chapter 3 in: D. Losic and A. Santos, Electrochemically Engineered Nanoporous Structures, Springer International Publishing, Switzerland, 2015

4] J. M. Macak, B.G. Gong, M. Hueppe, P. Schmuki, Adv. Mater., 2007, 19, 3027.

5] L. Wu & G. Zangari, J. Phys. Chem. C,
2010, 114, 1155

6] S. Das & J. M. Macak et al., ChemElectroChem, 2017, 4, 495

7] R. Zazpe et al, Langmuir, 2016, 32, 10551

8] S. Ng et al., Adv. Eng. Mater., DOI: 10.1002/adem.201700589

9] R.Zazpe et al., Nanoscale, 2018, 10, 16601-16612.

10] F. Dvorak et al., Appl. Mater. Today,
2019
, 14, 1-20.
Effects of Coordination Structure of Silicon Ions on Electrodeposition Process of Silicon in Fluoride Melts
Authors: Suzuki Yuta , Inoue Yosuke , Yokota Masayuki , Fukunaka Yasuhiro , Goto Takuya
Published: May 2020

Silicon electrodeposition in molten salts is a key technology for fabricating silicon films, as a material for solar cells, by environmentally friendly and inexpensive processes. We have already reported the electrodeposition of silicon films from SiO2 in fluoride melts. However, there are only few studies about the effects of ions in fluoride melts, such as O2- anion, and Li+/Na+/K+ cations, on silicon electrodeposition processes. In particular, it is important to understand the coordination structure of silicon ions for controlling the nucleation and growth processes between solid metal substrates and fluoride melts interface.

In this study, we investigated the electrodeposition of silicon from SiO2 in LiF-NaF-KF melts mixed with Li2O as a source of O2- anion at 873 K, and binary LiF-KF, LiF-NaF, and NaF-KF melts. The results of the in-situ Raman spectroscopy and DFT calculations indicated that the O2− anions could cleave the Si-O-Si bonds of SiO2 or silicate ions such as [Si2O5]2−; consequently, the formation of tetrahedron [SiO3F]3− species was promoted. In addition, electrochemical measurements, XRD, SEM, and EDS analysis showed thickness and current efficiency of electrodeposited polycrystalline silicon was affected by the difference in coordination structures of silicon ions in fluoride melts. This study suggested the design of the molten salts bath was significant for controlling interfacial phenomena at electrode/molten salts to fabricate high-quality Si layers with high current efﬁciency.
Amalgam Protection for Alkali Metal Anodes
Authors: He Guang , Li Qingwen , Zhang Qi , Ding Yi
Published: May 2020

The dendrite issue and the associated cell degradation problems have proved to be a key challenge to the practical application of alkali metal anodes.1,2 We present a simple yet efficient approach to fabricate amalgam anodes (Figure 1a) that afford long-term stability cycling at practical current densities and capacities.3 The amalgam layer allows fast electron transfer as well as Li/Na/K migration at the electrolyte-electrode interphase, which significantly promote the cycling performance. For example, Protected Li electrodes exhibit stable cycling over 750 hrs at high plating current and capacity of 8 mA cm-2 and 8 mAh cm-2 in symmetric cells (Figure 1b). Coupled with high-loading cathodes (~12 mg cm-2) such as LiFePO4 (LFP) and LiNi0.6Co0.2Mn0.2O2 (NCM), the prototype full cells also demonstrate much improved rate and long-term cycling stability (Figure 1c). In-situ optical microscopy analyses confirm the dendrite nucleation and growth can be remarkably suppressed with the Li-Hg protected anodes (Figure 1d). These promising results provide new perspectives on the regulation of sodium electrodeposition and hence the elimination of the dendritic morphology for the practical development of alkali metal batteries.

References:

1. X.-B. Cheng, R. Zhang, C.-Z. Zhao, and Q. Zhang, Chem. Rev., 117, 10403–10473 (2017).

2. R. Weber, M. Genovese, A. J. Louli, S. Hames, C. Martin, I. G. Hill, and J. R. Dahn, Nat. Energy, 4, 683-689 (2019).

3. G. He, Q. Li, Y. Shen, and Y. Ding, Angew. Chem. Int. Ed., DOI: 10.1002/anie.201911800 (2019).

Figure 1. a) The preparation process of Li-Hg protected anodes; b) Cycling performance of Li-Hg protected anodes and pristine anodes in symmetric cells; c) Cycling performance of Li-Hg protected anodes and pristine anodes in full cells with high-loading LFP and NCM cathodes; d) In-situ optical analyses showing the different Li deposition behaviors on Li-Hg protected and pristine anodes.

Figure 1
Effective Iodine Encapsulation for Rechargeable Zinc-Iodine Enclosed Battery
Authors: Kao-Ian Wathanyu , Kheawhom Soorathep
Published: May 2020

The increasing demand for electricity and the intense degree of electrification require greener, safer, and more cost-effective rechargeable battery technologies. Among these available technologies, lithium-ion batteries (LIBs) are the most feasible option for various applications. Nonetheless, LIBs show several drawbacks such as safety problems, recycling, and most specifically the cost and material abundance. One possible approach to address this issue is to replace lithium (Li) with a high volumetric capacity metal such as zinc (Zn). Zn has a higher specific volumetric capacity of 5,855 mAh cm-1 compared to that of Li (2,066 mAh cm-1). Besides, Zn has a lower cost. Even more, it is environmentally friendly, safe, and non-toxic. The redox capacity of Zn is -0.763 V vs. standard hydrogen potential (SHE). Thus, it is better for an aqueous electrolyte with the application of near-neutral electrolytes. Among various zinc-based redox chemistries, the I-/I2 redox couple shows the most promising and excellent electrochemical performances. Iodine has low cost and high abundance. The initial work of a zinc-iodine battery was demonstrated as a flow battery by the PNNL National Laboratory at Northwestern University. The battery shows excellent performance with high energy efficiency. However, a flow battery is not appropriate for portable application and requires periodic maintenance. Fabrication of zinc-iodine battery in an enclosed cell form factor is thus challenging. In this work, a zinc-iodine enclosed battery is demonstrated by encapsulating iodine (active material) and iodide species (discharge product) on the positive electrode material with activated carbon and anionic polyelectrolyte. Activated carbon adsorbs on iodine its surface and trapped in its pores, while anionic polyelectrolyte prevents iodide species from escaping the electrode surface. Though zinc-iodine cell is a conversion-type as the electrochemical reactions taking place during charging and discharging of the battery result in new chemical compounds, the behavior of the battery proposed is similar to an insertion-type battery. The charge storage and charge-transfer characteristics of the battery are examined. The results show that the battery exhibits an ultrafast charging rate of 6C-10C. The battery displays very high round-trip efficiency above 90%, even charging/discharging at 6C. Also, the cell shows excellent stability with low capacity fading (less than 5% after 2,000 cycles). Consequently, the battery exhibited excellent electrochemical performance, good cyclability with the maximum specific capacity of 145 mAh/gI at 1.5C. Overall, the proposed zinc-iodine enclosed cell is very promising for high rate applications.

Figure 1
Integrated Hybrid Fuel Cell-Battery Power Generator Enabled through Electrochemical Hydrolysis of Nanoporous Aluminum
Authors: Corsi John S , Fu Jintao , Lee Timothy , Detsi Eric
Published: May 2020

Over the past decade, tremendous progress has been made in transitioning from fossil fuel-based transportation to electric vehicles powered either by lithium-ion battery (LIB) or proton-exchange membrane (PEM) fuel cell technologies. A hybrid fuel cell-battery power generation system is more attractive than a battery alone, or a fuel cell alone, since a battery is able to meet the high-power requirements during peak demands (e.g. acceleration), while a fuel cell can be used as a range extender. Existing hybrid PEM fuel cell-battery power generation systems consist of separate LIB and PEM fuel cell systems that are coupled together. In this configuration, the hydrogen used to feed the PEM fuel cell is stored on-board in high-pressure tank.

In this talk, I will present our novel integrated hybrid PEM fuel cell-battery power generation system, which can simultaneously produce both electricity, acting as a battery, and hydrogen gas, which is then used to directly feed a PEM fuel cell, from a single device. We have previously reported the scalable synthesis of novel bulk nearly oxide-free nanoporous aluminum (NP-Al) and the ability to produce hydrogen gas through “chemical” hydrolysis of NP-Al in pure water, with solid aluminum hydroxide, hydrogen gas and heat as the only reaction products. [1] The new hybrid power system proposed here builds on this work through the introduction of a novel cell configuration which facilitates the spontaneous “electrochemical” hydrolysis of NP-Al, during which aluminum is oxidized at the anode, electrons from this oxidation reaction diffuse through an external circuit to the cathode where hydrogen evolution takes place, meanwhile electricity is also generated from electrons flowing through the external circuit. This electricity is the equivalent of the heat generated during chemical hydrolysis reaction, meaning that during electrochemical hydrolysis, the only reaction products in case of 100 % reaction efficiency are solid aluminum hydroxide, hydrogen gas and electricity without heat. In this talk, I will discuss this novel cell, current progress and outlook for future development.

Reference:

[1] Corsi JS, Fu J, Wang Z, Lee T, Ng AK, Detsi E. (2019). Hierarchical Bulk Nanoporous Aluminum for On-Site Generation of Hydrogen by Hydrolysis in Pure Water and Combustion of Solid Fuels. ACS Sustainable Chemistry and Engineering, 7, 11194–11204. doi.org/10.1021/acssuschemeng.9b00481
Understanding the Factors Impacting Battery Failure Propagation and Its Mitigation
Authors: Torres-Castro Loraine , Lamb Joshua
Published: May 2020

Developing battery systems resilient to thermal runaway propagation is of great concern when designing resilience into large battery systems. This is particularly difficult when working with pouch format cells as the format exists primarily to drive increased energy density within systems, which itself makes failure propagation more likely to occur. Our work focuses on module to module propagation and potential tools that might be used to mitigate this failure. We have constructed 3S3P configuration batteries with various mitigation strategies used to prevent module to module propagation. This has included conductive, insulating and advanced materials and is coupled with analysis of the heat transfer across these barriers to better understand the underlying mechanisms that can better improve propagation resistance in systems constructed with pouch format cells. We have used both mechanical and thermal initiation techniques to explore the different behaviors that might occur when the character of the initial failure changes as well. This includes the failure propagation from a single cell failure initiation as well as the failure of an entire 1S3P module within the pack. Finally, we look at the differing roles that both changes to energy density of the pack as well as changes to the heat transfer between cells might play in mitigating thermal runaway propagation.

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.
Nucleation, Pattern Development, and Fidelity in the Photoelectrodeposition of Se-Te Nanostructures
Authors: Simonoff Ethan , Van Munoz Lorenzo , Papadantonakis Kimberly , Lewis Nathan S
Published: May 2020

The electrochemical growth of Se-Te under polarized illumination results in anisotropic, highly-ordered lamellar nanostructures, tunable by input wavelength. This spontaneous growth occurs at room temperature, in an isotropic solution, with no templating or chemically-directing agents, and with mW-cm-2 illumination intensity with no requirement for coherency. The deposition process is compatible with a wide variety of conductive substrates and can be performed over large areas of unpatterned substrates. However, pattern fidelities in these films are generally low. Improving the potentially broad applicability of this patterning method requires an understanding of pattern development and of factors contributing to the long-range order of films deposited through this phenomenon.

Methods of quantifying pattern fidelity have been developed using Fourier-transform (FT) analysis of large-area images of photoelectrodeposited Se-Te films. Nominally identical illumination conditions during the deposition of Se-Te on crystalline (111)-oriented Si substrates doped degenerately with either p- or n-type dopants produced a variation in the morphology of Se-Te films. Films deposited on p+-Si generally displayed much less defective patterns, with a higher degree of anisotropy and a more well-defined pattern period versus films deposited on n+-Si. These results are attributed to the energetics at the dynamic junction formed by growing Se-Te and the Si substrate.

Analysis of film morphologies at early levels of mass addition to growth substrates elucidate the mechanism by which junction energetics affect resulting film morphologies. Higher nucleation densities are generally observed under conditions that produced Se-Te films with relatively higher pattern fidelities. Control of pattern fidelity by control of nucleation density, through substrate choice and tuning of applied deposition potential, is demonstrated.
Rational Compositional Control of Electrodeposited Ag-Fe Films
Authors: Sun Yunkai , Zangari Giovanni
Published: May 2020

In the field of alloys, be they bulk of thin films, systematic control of composition is a prerequisite to understand details of microstructure evolution and phase transformation. Because of the complete immiscibility of Ag-Fe, electrodeposition is capable of forming metastable structures, enabling an economical alternative to synthesis from vacuum methods. However, due to the negative redox potential of Fe(II)/Fe, Fe cations must be complexed in order to prevent the formation of hydroxides in the deposit. On the other hand, due to the difference in redox potential, Ag(I) will be spontaneously reduced by the plain Fe(II) bath due to the reaction Fe(II)/Fe(III). Using Fe(III) could prevent the spontaneous reduction of Ag(I) in the solution, however, hydroxides could form due to the small stability constant of Fe(OH)3. Furthermore, the fast Ag(I) reduction rate could lead to the formation of dendrites, an unfavorable morphology for achieving uniform and smooth alloy films. In order to achieve films with high quality, dimethylhydantoin (DMH) was used as a surfactants and complexation agents for Ag(I).

Herein we demonstrate the paradigm for designing this novel alkaline DMH-citrate for Ag-Fe deposition, compare the prediction from available thermodynamic data with the observed CV profiles of different baths, and rationalize its composition control at the limiting current range. Two aspects are highlighted:

Stabilization of the deposition bath: the solution instability is dominated by the redox pairs of Ag(I)/Ag and Fe(II)/Fe(III). Using plain Fe(II)/Ag(I) citrate-DMH solution, we observed gradual degrading of deposition bath with high Fe(II) concentration. Based on the mixed potential theory, Fe(III) is added to positively shift the redox potential of Fe(III)/Fe(II). By adding 1%at,Fe(II) of Fe(III), the open-circuit potential positively shifted for 0.07V and loss of Ag(I) in the solution was partially resolved.

Prediction of composition: after stabilization of the bath, the film composition at the limiting current condition could be predicted using a limiting current mass-transfer ratio. Small deviations from this prediction were found, probably caused by solution instability and formation of Fe(II) hydroxide species due to high pH.

In summary, we would like to draw attention to the electrodeposition process by highlighting the importance of complexation chemistry, that unusually here has the purpose of stabilizing the electrolyte with multivalent cations.

Graphical abstract:
Calculation results of redox potentials related to the DMH-citrate complexed Ag-Fe electrolyte based on the Nernst equation and thermodynamic data available, with the redox pair which influences the solution stability marked with arrows in the plot. The stabilized bath possesses a well-behaved linear trend between solution concentration ratio and film (deposited at limiting current condition) composition ratio.

Figure 1
(Invited) Underpotential Deposition and Alloy Co-Deposition
Authors: Moffat Thomas P , Gokcen Dincer , Bertocci Ugo , Mallett Jon , Liu Yihua , Ou Yang Liang Yueh , Hangarter Carlos M , Hwang Sun-Mi , Ambrozik Stephen , Dimitrov Nikolay
Published: May 2020

The interplay between ionic adsorption, underpotential deposition and excess bond enthalpy in the deposition of materials will be discussed based on selections from recent work. Examples of limiting behavior will be presented that range from the deposition of solid-solutions, e.g. Pt-Cu and Pt-Fe group alloys, to intermetallics, e.g. Pt-Pb, to immiscible, e.g. Cu-Pb, systems. In addition, contributions of “parasitic” electrolyte breakdown reactions on the deposition of elements and alloys will also be briefly discussed. Close coupling between electroanalytical, gravimetric, metallurgical and surface science measurements enable the underlying thermodynamic and kinetic influences on co-deposition process to be revealed.
(Invited) Film Properties of Various Electroless Plated Co Alloy Films Formed on SiO2/Si Substrate and Its Interdiffusion Properties Against Cu
Authors: Shingubara Shoso , Matsudaira Taro , Shimizu Tomohiro
Published: May 2020

There is a serious problem of poor side wall coverage for the sputtered barrier metals in high aspect ratio TSVs. We have proposed electroless plated Co-alloy barrier metals for TSV. For this purpose, we prepared various CoB and CoWB alloys with different atomic compositions and crystalline structures. Furthermore, we evaluated interdiffusion properties of Cu/Co-alloy/Si stacked structure by SIMS analysis. It turned out that the electroless CoWB film containing larger amount of W has excellent diffusion barrier property than other CoWB films with smaller W content.

We formed electroless barrier films of CoB and CoWB using Pd nanoparticle catalyst on SiO2/Si substrate [1]. For evaluation of Cu interdiffusion properties by SIMS, we deposited Cu and TiN thin films successively by sputtering on the barrier film. The ratio of the atomic composition was changed by adjusting the ratio of cobalt sulfate, tungstic acid, and some other contents of the plating bath. SIMS depth profiles of CoB (Fig.1-a) and CoWB films after annealing at 400 ℃ (Fig.1-b) are shown in Fig.1. There was a large interdiffusion between Cu and CoB after 400 ℃ annealing (Fig.1-a). Co-Silicide formation significantly occurred and Si atoms diffused into CoB layer. However, interdiffusion was significantly suppressed in the case of Co-20%W-B film (Fig.1-b). These results suggest that W atoms existed in CoWB have a strong effect of suppressing Cu diffusion in Co film, and CoWB with 20 atom % W showed a good diffusion barrier property. The present study suggests that the electroless plated CoWB having a larger W content has a high potential as a diffusion barrier film for the via last TSV process.

[1] F. Inoue, T.Shimizu, F.Miyake, R.Arima, T.Ito, H.Seki, Y.Shinozaki, T.Yamamto, and S.Shingubara, Microelectronic Engineering, 106 (2013) 164–167.

[2] T. Iseri, S.Shindo, Y.Miyachi, A.Hirate, S.Tanaka, T.Shimizu, T.Ito, S.Shingubara, Jpn. J. Appl. Phys. 57 (2018), 07MB02-1~6.

Figure 1
Electrodeposition Transition Metal Alloy Films for Magnetic Thermometry
Authors: Rus Eric D , Dennis Cindi L , Moffat Thomas P
Published: May 2020

Knowledge of the temperature distribution within three dimensional volumes is of great importance to applications in many fields, but there does not currently exist a method for microscale temperature measurement throughout a volume. As part of an effort to develop methodology for 3D thermometry, the present work seeks to develop materials and structures with temperature-dependent magnetic properties that provide optimal sensitivity in the 200 K to 400 K range, leveraging previous work which demonstrated compositional control of alloys films by varying the deposition potential.[1] Preliminary room temperature vibrating sample magnetometry measurements on a series of platinum nickel alloy films showed ferromagnetic behavior for samples deposited at more reducing potentials (higher nickel content) and paramagnetic behavior for samples deposited at more positive potentials (higher platinum content). Herein, we will discuss deposition and characterization of these films with an emphasis on factors affecting their temperature-dependent magnetic properties.

[1] J. J. Mallett, E. B. Svedberg, J. E. Bonevich, A. J. Shapiro, W. F. Egelhoff, T.P. Moffat, J. Electrochem. Soc., 2008, 155, D1-D9.
Electrodeposition of Novel Nano-Composite Coatings of Niw Containing SiC and CeO2 with Outstanding Tribological Properties and Corrosion Performance
Authors: Dadvand Mina , Savadogo Oumarou
Published: May 2020

A special electrodeposition process utilizing a well-designed reversed pulse (RP) current waveform and specially formulated bath chemistry were used to produce nanostructured composite coating of nickel-tungsten (NiW) containing silicon carbide (SiC) and cerium oxide (CeO2). In this bath formulation, a specific type of propargyl derivative compound was used as a grain refiner due to its acetylene-type of bonding (i.e. -C≡C-H) at the end of its alkyl chain. This typical bond had a tendency to be adsorbed at high current density locations on the substrate being plated resulting in better control of nickel ion diffusion towards the cathode. Therefore, a uniform and defect-free deposit with mirror-finish surface was obtained. As well, this compound increased the nucleation sites for initiating of metal deposition on the surface of substrate resulting in the decrease in grain size of nickel. The resulting material demonstrated outstanding corrosion and tribological performances. It was found that the addition of SiC and CeO2 improved the corrosion performance of NiW. It was also found that the composite of NiW-SiC obtained by RP waveform, performed better in corrosion resistance compared to the same coatings deposited by DC waveform. The electrochemical corrosion tests including potentiodynamic polarization (PP) and cyclic potentiodynamic polarization (CPP) tests were used to evaluate the corrosion behaviors of the deposits. Following the PP tests, Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) was used to investigate the various corrosion products on deposits. As well, tribological properties including hardness, and wear resistance of the deposits were investigated
Investigation of Au-Ag-Cu Alloy Electrodeposition to Electromechanical Systems
Authors: Cagan Berkay , Erdogan Metehan , Karakaya Ishak , Yilmaz Cemil , Yurdakul Burak
Published: May 2020

Electromechanical systems, which provide electrical power and data connection between moving terminals, require high conduction and errosion resistant surfaces. Transference of electrical power and data are carried out by the contact of drum and brush wires. The electrochemical deposition of desired Au-Ag-Cu alloy compositions was investigated in this study. In the scope of the study, the static potential and cyclic voltammetry behaviours of gold, silver and copper cyanide plating baths, as well as the mixtures of binary and ternary baths were investigated to obtain suitable amount of KCN and working potential values. Beside SEM and EDS analyses, hardness and friction measurements were conducted in the characterization of coated samples.
Simultaneous Electrochemical Degradation of Toxic Food Dyes Wastewater Using Ti/Ru0.3ti0.7o2 composite Electrode
Authors: Hussain Sajjad
Published: May 2020

Food dyes constitute a highly diverse group of colouring agents usually used to colour a vast variety of food products. It has been estimated that 15% of total dyes produced worldwide are discharged to water bodies which adversely effects aquatic ecosystem. Dyes in water reduces its transparency thereby declining light penetration in to water hence influencing photosynthesis which consequently reduces dissolved oxygen which is alarming situation for both aquatic flora and fauna. When these dyes are taken in through food by man they induce carcinogenic, cytotoxic, genotoxic and allergic actions, thus poses serious threats to their lives. This study is primarily aimed to assess the efficacy of Ti/Ru0.3Ti0.7O2 electrode to address dyes (Tartrazine and Sunset Yellow) pollution abatement. All experiments were carried out in a 500 mL laboratory scale glass reactor by bulk electrolytic method. The influence of various operational parameters like pH (03 to 10), applied current densities (2.5 to 10 mA cm-2), different NaCl electrolyte concentrations (0.02 to 0.08 mg L-1) and different dye doses on electrochemical degradation of dyes were determined. The progress of decolourization process of twin dyes was monitored regularly by UV-Visible Spectrophotometry while the extent of mineralization was investigated by total organic carbon (TOC) analysis. Moreover energy consumptions of electrochemical treatments were calculated to probe into the process liability for industrial application in future. The electrodes were characterized in situ by Cyclic Voltammetry (CV) in appropriate electrolytes i.e. Na2SO4 and NaCl with each dye separately. The results demonstrated that electrochemical degradation of both dyes were more favored at higher applied current densities and elevated NaCl concentration under weakly acidic medium (pH = 03 to 06). Furthermore the degradation of both dyes was more likely to occur rapidly under low dyes doses rather than higher doses. Out of all electrolytes the NaCl was concluded as best supporting by virtue of its excellent dyes degradation efficiency and low energy consumption.
A New Strategy of Using Cation Intercalation Electrodes for Water Desalination
Authors: Kim Taeyoung , Namvar Shahriar
Published: May 2020

Water desalination is a promising technological solution to water scarcity. While several technologies are currently utilized to produce freshwater from saline water sources, there are remaining challenges including intensive energy usage (e.g., thermal distillation), fouling (e.g., reverse osmosis), and high material costs (e.g., electrodialysis). The use of cation intercalation electrodes allows for electrochemically driven capture and release of ions, thus effectively desalinating water using inexpensive electrode materials that require low voltage without producing byproducts. To date, previous approaches using cation intercalation electrodes have focused on intercalation and deintercalation of Na+ in order to directly capture Na+ that is abundant in saline water. This approach has limited the choice of electrode materials and electrochemical properties, which are crucial for efficient water desalination. To overcome this challenge, we demonstrated a new strategy for water desalination using cation intercalation electrodes that interact with K+. Water desalination was achieved in a 4-channel electrochemical flow cell separated by an alternative array of anion and cation exchange membranes with copper hexacyanoferrate (CuHCF) as a model electrode material. Deintercalation of K+ upon oxidation of CuHCF enabled the transport of Cl− through an anion exchange membrane from the adjacent channel that produces desalinated water. Intercalation of K+ upon reduction of CuHCF enabled the transport of Cl− through an anion exchange membrane to the adjacent channel that produces concentrated water. A cation exchange membrane located between desalinated and concentrated water channels allowed for separating Na+. Using the new concept of utilizing K+, several performance parameters were evaluated including electrochemical properties, salt separation, and energy consumption. Collectively, we show that the use of K+ as an intercalant for cation intercalation electrodes can represent a new strategy for electrochemical water desalination.
Electrochemical Pressure Impedance Spectroscopy As a Diagnostic Method for Hydrogen-Air Polymer Electrolyte Fuel Cells
Authors: Zhang Qingxin , Eikerling Michael Hermann , Gates Byron D.
Published: May 2020

Water transport in an operating hydrogen-air fuel cells has gathered the interests of both researchers and developers working on fuel cells. Better water removal can extend the operation regime of fuel cells and, therefore, increase its maximum cell power and overall energy efficiency. However, state-of-art in situ fuel cell diagnostics cannot provide an insight into the water transport phenomenon. Recent research shows that pressure controlling techniques have the potential to address issues with water transport. The purpose of this work is to develop an in-situ diagnostic tool from cathode pressure oscillations for hydrogen-air polymer electrolyte fuel cells named as electrochemical pressure impedance spectroscopy (EPIS). The response between the cell voltage and the pressure oscillations is analogous to the electrochemical impedance spectroscopy (EIS)(See image). The relation between EPIS response and water transport phenomenon is intensively studied in this work. With the help from our industrial partner, Greenlight Innovation Corp., we are able to integrate this diagnostic method into a fuel cell test station. Experimental data are fitted by the mathematical derivation of the response from theoretical cell components from which are extracted crucial parameters and diagnostic information for water transport.

Figure 1
Electrodeoxidation of Iron Oxide in Aqueous NaOH Electrolyte
Authors: Haarberg Geir Martin , Khalaghi Babak
Published: May 2020

The production of iron and steel contributes to ~10 % of global CO2 emissions. Electrolysis is an alternative route to eliminate CO2 formation. Experiments were carried out in NaOH-H2O (50-50 wt%) electrolyte with a suspension of Fe2O3 particles at ~100 oC. A rotating disk electrode was used as the cathode. Different cathode substrates of different graphite qualities and silver were used. The current efficiency for iron deposition was consistently higher than 90 %. Silver was found to be an excellent substrate for good quality deposits.

Cathodes in the form of pellets of hematite were also found to be reduced to iron by electrodeoxidation in the same electrolyte. Bauxite residue is a waste product from the Bayer process to produce aluminium oxide. The high content of iron oxide makes it a candidate for electrodeoxidation in a similar way.
High Performance Oxygen Depolarized Cathodes for Chlor-Alkali Electrolysis Using Electrospun Poly(vinylidene fluoride) (PVDF) Barrier Layers
Authors: Gebhard Marcus , Franzen David , Paulisch Melanie , Tichter Tim , Turek Thomas , Manke Ingo , Roth Christina
Published: May 2020

The industrial production of chlorine via chlor-alkali electrolysis has a significant share of the global energy demand. Significant savings in electrical energy are achieved by using oxygen-depolarized cathodes (ODCs) at the cathode side of the electrolyzer to replace the thermodynamically unfavorable hydrogen evolution reaction. In this manner, the overall cell potential can be lowered by ~1V at industrially relevant conditions (80-90 °C, 30 % NaOH electrolyte). Conventionally used ODCs are porous gas diffusion electrodes consisting of a micro sized silver powder as catalytically active material and polytetrafluoroethylene as hydrophobic binder. With this study, we present a novel and cost effective strategy based on the electrospinning technique to improve the efficiency of commercial ODCs. We demonstrate that implementing a thin hydrophobic layer of poly (vinylidene fluoride) into the electrode structure during the preparation process significantly enhances the electrode performance. In this manner, we are able to reduce the overpotential at industrially relevant current densities of 4 kA m-² by 70 mV. Electrochemical characterization is performed by using linear-sweep-voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) followed by distribution of relaxation times (DRT) analysis. It is proposed that the enhanced electrode performance is mainly caused by an increase in the electrochemically active surface area kept accessible by the hydrophobic layer during operation.

Figure 1
Electrochemical Study of Iron Deposit in Acid Media for Its Recovery from Spent Pickling Baths Regeneration
Authors: Miranda-Alcantará Berenice , Castañeda Federico , Ortiz Luis Antonio , Antaño López Rene , Orozco Germán , Rivera Fernando Felipe
Published: May 2020

Electrochemical technologies for the regeneration of spent pickling baths are feasible since they allow simultaneous metal deposition and acid production in the same process unit. In this work, the effect of Fe2+ concentrations on the electrochemical iron deposition from model spent pickling baths is analyzed by voltammetry switching potentials, Tafel plots and spectrum-electrochemistry studies. The analysis showed that the electrodeposition rate and potential decreased as Fe2+ concentration increased. Moreover, at higher Fe2+ concentrations, a decrease on the hydrogen evolution reaction was observed. Moreover, chemical Fe dissolution is present at all concentrations studied, due to the high corrosion rate of iron at low pH of the model bath. Thermodynamic diagrams and electrochemical tests coupled to UV-Vis analysis demonstrated the presence of iron sulfate complexes suggesting that iron deposit is conducted by an inner sphere layer mechanism.
(Invited) Phase Evolution and Interfacial Strain in Electrode Materials for Batteries
Authors: Su Dong
Published: May 2020

Advanced (scanning) transmission electron microscopy ((S)TEM) techniques have been intensively applied to study the materials for energy storage. With/Combining different TEM techniques, including in-situ TEM and diffraction, HAADF-STEM, and STEM-electron energy-loss spectroscopy, researchers are able to probe local structural and chemical information of electrode materials, at a resolution of nanoscale. This talk will focus on my recent work on using in-situ and analytical TEM to characterize the conversion-reaction oxide material (Fe3O4) for electrode of lithium ion batteries [1-3]. The dynamical process of the redox reaction of Fe3O4 revealed by in-situ TEM may help us to understand how reaction pathways affect the batteries’ kinetic properties.

Reference
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[1] He K. et al., Visualizing non-equilibrium lithiation of spinel oxide via in situ transmission electron eicroscopy, Nature Communications, 7,11441 (2016)

[2] Hwang S. et al., Strain coupling of conversion-type Fe3O4 thin film for lithium ion battery, Angewandte Chemie, 56,7813, (2017)

[3] Li J. et al. Phase evolution of conversion-type electrode for lithium ion batteries, Nature Communications, 10,2224 (2019)
Investigation of Electron-Beam Induced Damage in Lithium-Ion Batteries
Authors: Jaberi Ali , Zaghib Karim , Gauvin Raynald
Published: May 2020

Lithium-ion batteries are extensively used to transform chemical energy into the electrical energy and vice versa. These batteries are inevitably the best candidates for portable devices such as mobile phones, laptops and specially in the fast-growing market of electrical automobiles. The performance of these batteries is strongly connected to the microstructure of their electrodes. Thus, improvement of lithium-ion batteries requires an accurate structural investigation of their electrodes which is achievable by using electron microscopes.

However, the electron microscopes may damage the specimen during the investigation process. Once the beam electrons penetrate into the material, the columbic force of nucleus and electrons can scatter the beam electrons. When beam electrons undergo high angle scattering events, the law of conservation of momentum required momentum transfer to the atoms in the sample. In cases where the transferred energy is large enough to overcome a barrier called displacement energy (Ed), the atom can be displaced from its original lattice site. This displacement of atoms is called knock-on displacement, a significant source of electron beam damage. As a light element, Lithium has very small displacement barrier which makes the lithium base electrodes vulnerable to the high energy beam of electron microscopes.

In this study, we use a Density Functional Theory (DFT) based method called Nudged Elastic Band (NEB) to calculate the displacement energies. These values were then applied to the conservation of momentum to find the threshold displacement energy which is the beam energy that creates the knock-on damage inside the material during the electron microscopic investigation. Finding the safe electron beam energy range opens a new door for more accurate structural characterization of lithium compounds as a step for further improvement of lithium ion batteries.
Chemistry, Microstructure, and Interphases of Magnesium Metal Anodes Captured Via Cryogenic Electron Microscopy
Authors: Long Daniel , McClary Scott , Hahn Nathan T , Zavadil Kevin R , Watt John , Jungjohann Katherine L
Published: May 2020

Lithium-ion batteries are an important component in mobile electronics; however, their modest energy density makes them less than ideal for use in all-electric vehicles or localized grid residential/commercial energy storage. Multivalent-ion batteries (MIBs), including Mg2+, are promising high-energy density technologies that are cheaper and more abundant than lithium. Realizing the high theoretical energy density of MIBs requires the native multivalent-ion metal to be used as the anodic electrode, where densely controlled metal plating and stripping has yet to be achieved. The mechanisms governing plating/stripping of MIBs and the resulting microstructural impact on the battery performance must be understood before MIBs can be employed commercially. Understanding the role that the solid electrolyte interface has on multivalent-ion metal plating/stripping may lead to solutions for controlling reversible anodic cycling.

Recent advances in cryogenic electron microscopy(cryo-EM) preparation have allowed for scanning transmission electron microscopy (STEM) investigation of intact solid/liquid interfaces and electron-beam-sensitive materials. Here we present results of our chemical and microstructural investigation of plated and stripped Mg2+ anodes, collected with cryo-FIB preparation, cryo-transfer, and cryo-STEM. Details will be presented on the anode porosity, grain orientation maps, chemical maps from the electrode/electrolyte interfaces, and high-resolution structural imaging of the electrode interfaces.

This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. DOE’s National Nuclear Security Administration under contract DE-NA-0003525. The views expressed in the article do not necessarily represent the views of the U.S. DOE or the United States Government.
In-situ and Operando Characterization of Battery Materials using X-rays
Authors: Sommariva Marco , Dadivanyan Natalia , Nenert Gwilherm , Fransen Martijn , Degen Thomas , Masiello Fabio , Bao Zhaohui , Wang Lin , Speakman Scott , Hawkridge Mike , Gateshki Milen
Published: May 2020

X-ray diffraction, scattering and imaging are powerful tools for the study of battery materials [1, 2]. In this work we describe several X-ray methods, which can provide a wealth of information about new materials used in battery applications. By using X-ray diffraction (XRD) it is possible to identify the different crystallographic phases, and with the Rietveld method [3] it is possible to refine the crystallographic structures of the different materials and quantify the amount of each phase in the bulk material. It is also possible to perform in situ and operando XRD measurements of the complete battery cells. This can be done either in reflection or in transmission geometry [4-6]. In order to perform the measurements in transmission geometry, radiation with higher energy is required, e.g. Mo or Ag X-ray anodes. A newly developed Malvern Panalytical X-ray detector (GaliPIX3D) allows for shorter measurement time and/or better data quality thanks to the higher efficiency of the CdTe sensor material [7]. In addition, the short-range structure of crystalline, nano-crystalline and amorphous materials can be studied with the Pair Distribution Function method (PDF), based on a total scattering approach. Also for this technique, hard X-ray radiation (Mo or Ag anodes) is required. Imaging is also a very useful technique, enabling detailed view of the interior structure of the battery in a non-destructive way. All X-ray scattering and imaging experiments can be performed on a single X-ray instrument, such as a Malvern Panalytical Empyrean multipurpose diffractometer.

[1] E. Talaie et al., Energy & Environmental Science 8, 2512-2523 (2015)

[2] Z. Liu et al., Chemistry of Materials 26(8), 2513-2521 (2014).

[3] H.M. Rietveld, J. Appl. Cryst. 2, 65 (1969).

[4] I. Buchberger et al., Journal of The Electrochemical Society 162(14), A2737-A2746 (2015).

[5] N. Sharma et al., ChemSusChem, 8, 2826-2853 (2015).

[6] E. Talaie et al., Chemistry of Materials, DOI: 10.1021/acs.chemmater.6b02726 (2016).

[7] G. Confalonieri et al., Powder Diffraction Journal, 30(2), Supp. 1, S65 (2015).