bluuebunny/crossref_metadata_2025 huggingface dataset:
Bubble Behavior and Anode Effect on Different Carbon Anode Designs in Cryolite Melt Applying a See-through Furnace
Authors: Stanic Nikolina , Martinez Ana Maria , Einarsrud Kristian Etienne , Sandnes Espen
Published: September 2023

Anodic CO2 gas evolution is one of the main processes in the Hall-Héroult electrolysis cell for primary aluminium production. This work is a laboratory scale study of the effect of anode geometry, anode orientation and carbon anode material on bubble behavior and bubble properties in cryolite melt. Increased knowledge of the bubble behavior is important for improved design of industrial cells, but also for laboratory‐scale experiments. The anodes studied in this work are frequently applied for investigation of reaction kinetics and mass transport, anode effect, current efficiency, anode quality properties, etc. It is therefore of interest to study the bubble dynamics of these anodes in more detail because bubble evolution is relevant for all the above-mentioned phenomena.

The anode potential has been shown to be highly dependent on anode geometry and orientation. For this study four different anode designs were made: horizontal (downward-facing), inverted horizontal (upward-facing), vertical, rod (with both vertical and horizontal surface). For most of the designs, characteristics such as bubble noise, bubble size, and wetting were obtained as a function of current density or anode potential/cell voltage. The bubble noise normally went through a maximum, while the bubble size decreased in the whole current density range. The wetting contact angle showed little variation with current density. It was assumed that the current density had a stronger effect on the contact angle through its effect on the bubble size than the polarization and associated surface roughening.

Also, phenomena like nucleation, growth, coalescence, bubble detachment and anode effect were studied for both graphite and industrial carbon as anode material. The nucleation was more pronounced at the industrial carbon due to more active sites confirmed by CT analysis. The coalescence process was found to be independent of current density/potential and carbon anode material and was in the range 16-24 msec. On increased currents anode effect occurred on both anodes, the current being lower for the graphite anode at onset. Video recordings and electrochemical measurements showed more abrupt initiation of the anode effect on the graphite and a strong de-wetting of the anode. With the existence of a (C – F) surface compound on the anode, as long as the anode effect gas could escape the electrode surface, the anode seems to be electrochemically active towards both CO/CO2 and PFC formation during anode effect.

In addition to the bubble characteristics and phenomena described, the impact of the results for better anode design for laboratory scale studies is discussed.
Understanding the Crystal Chemistry of Phosphate Cathode Materials
Authors: Murgu Roxana Nicoleta , Gover Richard K. B. , Payne Julia Louise
Published: September 2023

Thermal batteries are primary reserve batteries that can achieve high power output in a short period of time by melting an insulating salt electrolyte with a pyrotechnic heat source and converting it into a highly conductive eutectic salt electrolyte. The thermal battery exhibits no self-discharge before activation, and the initial capacity of the thermal battery is maintained after long-term storage. Thermal batteries are an attractive option for emergency power supplies in aircraft, ejector seats, space landings and helicopters due to their outstanding robustness, high reliability, and long-term storage properties.

FeS2 or CoS2 are the most common cathode materials for thermal batteries.1 However, their high cost and relatively low discharge voltage makes it desirable to find new materials that have higher voltage discharges, higher specific capacities, low cost and that are environmentally friendly. Polyanion cathode materials have attracted much attention in the field of both Li-ion and Na-ion batteries,2–4 as they can be regarded as low-cost materials and environmentally friendly. However, to the best of our knowledge, there have been no studies on polyanion cathode materials for thermal batteries. These materials are formed by tetrahedral units (XO4)n- (X = P, S, Si or B) bonded to MO6 polyhedra (M = transition metal). The tetrahedral anion presents a very strong covalent bond between X-O, giving rise to higher voltages versus Li+/Li or Na+/Na via the inductive effect and their very stable framework and open structure facilitates ion diffusion. Thus, polyanion materials present high structural stability and enable the tuning of the operating potential, making them an excellent choice for developing new cathode materials for thermal batteries. Here we report some of our latest work on the synthesis, structure and electrochemistry of polyanionic cathode materials for thermal batteries.

1 R. Li, W. Guo and Y. Qian, Front. Chem., 2022, in press, doi: 10.3389/fchem.2022.832972

2 Z. Gong and Y. Yang, Energy Environ. Sci., 2011, 4, 3223–3242.

3 C. Masquelier and L. Croguennec, Chem. Rev., 2013, 113, 6552–6591.

4 Q. Ni, Y. Bai, F. Wu and C. Wu, Adv. Sci., 2017, 4, 1600275.
Understanding Electrochemical Growth of Carbon Nanotubes from CO2
Authors: Wong Andrew Barnabas
Published: September 2023

Previous works have pioneered the observation of carbon nanotube growth in molten LiCO3 electrolytes from CO2. However in many past works, several CO2-derived cathodic carbon morphologies were observed, which included carbon particles/spheres, graphite flakes, carbon nanofibers, CNTs, and graphene-like ultrathin carbon sheets. Moreover, these morphologies are often mixed, resulting in a low selectivity and difficult separation towards one single carbon morphology, and the factors leading to various morphologies are not currently well understood. In this talk, we will explore the fundamental growth mechanism to inform the broader long-term goal of improving the selectivity towards carbon nanotubes from CO2. This present work studied the cathodic growth of carbon nanotubes by utilizing a simple three-electrode configuration consisting of pure Li2CO3 electrolyte, pure transition metal foil cathodes, Pt anode, and homemade Ag/Ag2SO4 reference electrode to determine the impact of tunable parameters on the resulting electroreduction products.
(Invited) Aerosol Jet and Laser Assisted Electrochemical Deposition for Advanced Metallization
Authors: Gibertini Eugenio , Bernasconi Roberto , Magagnin Luca
Published: September 2023

The inkjet printing technology for conductive patterns is commonly conducted with inks that are made of metal nanoparticles or based on metal-organic decomposition. An additional step of sintering, which is usually done in oven or on a hot plate, is required after inkjet printing to obtain metallic patterns with desired electrical conductivity [1]. Laser-induced selective metal deposition on metallic and non-metallic substrates has been the subject of much attention recently. An induced deposition rate several orders of magnitude greater than conventional rates is claimed to occur at points where a laser beam impinges the electrode surface [2].

In this work, electrolytic and electroless deposition processes are combined with aerosol jet technology and laser assisted setups to induce local metallization on metallic and non-metallic substrates. Single metals and alloys deposition will be discussed according to compatibility with the substrates, selectivity and achievable feature size. Examples of microfabrication and selective decorative applications will be provided, together with an evaluation of the properties of the produced deposits.

J-J. Chen, Fabrication of conductive copper patterns using reactive inkjet printing followed by two-step electroless plating, Applied Surface Science 396 (2017) 202–207.

R. Khan, Laser-Induced Selective Deposition on Metal Using Electroless Gold, NASF SURFACE TECHNOLOGY WHITE PAPERS 84 (2019) 6-13.
(Invited) Whisker Growth during Adsorbate Suppressed Electrodeposition
Authors: Braun Trevor Michael , Osborn William , Moffat Thomas P
Published: September 2023

Anisotropic electrochemical deposition and whisker growth is shown to be a consequence of operating a bistable active-passive critical system under galvanostatic control. Specifically, whisker growth is examined during galvanostatic Cu electrodeposition from an electrolyte containing suppressor additives. Disruption of the passivating polyether-halide bilayer triggered by metal deposition leads to positive feedback and highly localized deposition. On macroscale electrodes active-passive Turing patterns develop while on micrometer-sized electrodes the bifurcation is frustrated and proceeds as a single active zone reinforced by hemispherical transport fields. Extended electrodeposition leads to symmetry breaking and lateral propagation of a single whisker. An increasing fraction of the applied current supports expansion of the passive sidewall area and eventually results in termination of anisotropic deposition. The dynamic range between passive versus active growth determines the shape and extent of whisker formation. Similar critical behavior may account for reports of whisker growth in certain metal/metal ion battery systems.
Electrohydrodynamic Redox Printing: A Swiss Army Knife of Metals Microfabrication?
Authors: Nydegger Mirco , Porenta Nikolaus , Reiser Alain , Spolenak Ralph
Published: September 2023

The dissolution and deposition of metals in solvents is widely known and used in a large range of applications, from electroplating to electro-machining. More recently, it has also been used for additive manufacturing (AM) at the sub-micron scale, since electroplated metals offer as-deposited high-quality metals (in terms of porosity and contamination) compared to other small scale AM techniques [1,2]. These intricate, high-quality metal structures have a range of applications in microelectromechanical systems, photonics or micro-robotics. However, the nature of the deposition process requires a conductive substrate to provide the electrons necessary for the localized reduction of metal ions. This requirement renders the direct fabrication of microelectronic devices using electrochemical small scale AM a challenge, as often deposition on electrically insulating substrates is required.

Here, we present our work on electrohydrodynamic redox printing (EHD-RP), an electrochemical small scale AM technique, and our efforts towards deposition on various substrates. We’ll first introduce EHD-RP with a focus on our recent work on the deposition from aqueous metal salt solutions onto conductive substrates. We’ll then discuss strategies to expand the concept of EHD-RP towards deposition on non-conductive substrates and how electrically floating structures can be fabricated. These strategies render EHD-RP a versatile technique for metals microfabrication.

[1] M. Nydegger, A. Pruška, H. Galinski, R. Zenobi, A. Reiser and R. Spolenak. Additive Manufacturing of Zn with Submicron Resolution and its Conversion into Zn/ZnO core-shell structures. Nanoscale, 2022

[2] L. Hirt, A. Reiser, R. Spolenak and T. Zambelli. Additive Manufacturing of Metal Structures at the Micrometer Scale. Adv. Mater., 29(17), 2017
Electroplating on Unconventional Ultra-Compliant Substrates for Travelling Wave Tube Amplifiers
Authors: Chaudhary Anjali , Prakash Divya J. , Jacobson R B , A Scott Shelley , E Savage Donald , van der Weide Daniel , Lagally Max , Cavallo Francesca
Published: September 2023

We report gold electroplating on ultra-compliant substrates comprising helical slow wave structures (SWSs) for traveling wave tube amplifiers (TWTAs) [1]. The novel ultra-compliant substrates are composed of edge-tethered tri-layer metal ribbons with a helical geometry of microscale diameter. After electroplating with gold, we obtain overall thicknesses of a few um. We discuss different controllable electroplating conditions that influence thickness, uniformity, roughness, and related properties of deposited gold films on helical ribbons. In addition to increasing conductance of the electroplated helical ribbons, electroplating stabilizes the helix at its equilibrium diameter, with the pitch predicted by Prakash et al.[1].

Our method of fabrication of ultra-compliant helical ribbons starts with defining strips of width 5 µm to 10 µm by optical lithography, metal evaporation, and lift-off, deposited on Si substrates coated with a sacrificial layer of Ge or GeOx,. We use Cr/Au/Cr tri-layers to create an inherent stress gradient that causes the strip to self-assemble into a helix, after etching with XeF2 for selective removal of a sacrificial layer. Diameter and pitch of the released helices are controlled by varying the thickness, the elastic modulus, the residual stress, and the in-plane geometry of the deposited tri-layer metal strips. The gold electroplating process uses a sulphate-based gold solution in a two-electrode electrochemical setup with the helix as the cathode and a platinized mesh as the anode [2]. We deposit gold to a thickness of a few um, using a pulsed current source with variable parameters. Direct current can also be used with smaller deposition times. Our results demonstrate the application of electroplating to unconventional ultra-compliant helix of nanoscale dimensions.

Reference

[1] Divya J. Prakash,., Matthew M. Dwyer, Marcos Martinez Argudo, Mengistie L. Debasu, Hassan Dibaji, Max G. Lagally, Daniel W. van der Weide, and Francesca Cavallo. 2020. “Self-Winding Helices as Slow-Wave Structures for Sub-Millimeter Traveling-Wave Tubes.” ACS Nano, 2021, 15, 1229-1239. doi:10.1021/acsnano.0c08296.

[2] Max G. Lagally, Anjali Chaudhary, Daniel van der Weide, Divya J. Prakash, and Francesca Cavallo, Improved Self-assembly of Helices via Electrodeposition on Freestanding Nanoribbons for TWT Application, provisional US patent application (P220249US01)

Work supported by U.S. AFOSR-Award No FA9550-22-1-0086.
Electrodeposition of Ag-Ni and Pd-Ni Thin Films on Ni-P from a DMSO Solution
Authors: Eyraud Marielle , Bahramian Ahmad , Vacandio Florence , Knauth Philippe
Published: September 2023

The most used electrical contact system in electronics and microelectronics is Cu/Ni(Ni-P)/Au, which offers an interesting combination of high electrical conductivity, corrosion resistance, and wear resistance. However, the top Au thin layer being porous, a galvanic coupling between NiP and Au, and then Cu and Au appears that renders the system unusable. Au being highly expensive, the development of more inexpensive and reliable plating materials such as Ag or Pd can be experimented. Ag is widely considered as an economical alternative to Au. Ag and Au top-coats are traditionally obtained from highly toxic cyanide baths. Therefore, recent studies focused on developing non-cyanide electrolytes, Dimethyl sulfoxide (DMSO) being a promising solution for noble metal deposition.

Hard noble coatings, i.e. alloying the noble metal with Ni, Fe, or Co, have a lower content of the noble metal and offer a higher hardness and thus a superior wear resistance. The electrodeposition of Ag-Ni and Pd-Ni layers on Ni-P from a non-cyanide DMSO based electrolyte was investigated, which was especially challenging for Ag deposits given the fact that Ag and Ni are totally immiscible in all the states. The chemical composition and morphology of these systems were highly affected by the applied potential. Therefore, the pulse deposition was used to form films on Ni-P coatings, i.e. a high cathodic potential (-1 V vs. Ag/AgCl) for the preferential deposition of Ni, and a lower value for the preferential deposition of the noble metal (here Ag or Pd). The obtained coatings showed a good adhesion to Ni-P. The Ag-Ni top-coats showed a nanocrystalline structure and presented a higher concentration in noble metal than Pd-Ni. This result was attributed to the formation of stronger DMSO complexes with Pd than with Ag.
Optical Characterisation of Plasmonic Indium Lattices Fabricated Via Electrochemical Deposition
Authors: Valenti Marco , Wobben Merlinde D , Bleiji Yorick , Cordaro Andrea , Tabernig Stefan Wil , Aarts Mark , Buijs Robin D. , Rodriguez Said Rahimzadeh-Kalaleh , Polman Albert , Alarcón Lladó Esther
Published: September 2023

Indium is an emerging plasmonic material that offers to extend the plasmonic applications given by gold and silver from the visible to the ultraviolet spectral range, with applications in imaging, sensing, and lasing. However, due to the high-vapor pressure/low melting temperature of indium, nanofabrication of pre-defined metallic indium nanostructures is non-trivial.

In this work, we show the potential of selective area electrochemical deposition for the manufacturing of large-area arrays of indium pillars, which can be used for plasmonic applications. We combine electrochemical deposition with substrate-conformal imprint lithography to realize these large-scale indium nanoparticle arrays, having well-defined dimensions. This template growth results into well-defined hexagonal array of pillars with a mean height of 235 nm having a standard deviation of 60 nm.

To highlight the potential of this electrochemical-based technique for plasmonic applications, we have performed angle-dependent extinction measurements using s-polarized light and using a RI matching oil. We found that these indium nanopillar arrays exhibit a strong plasmonic response due to the coupling to the plasmonic surface lattice resonances (SLRs). Furthermore, we have simulated the optical response of this indium nanopillar array using finite difference time domain (FDTD) simulations. In these simulations, we included the morphology obtained from SEM and the electrical permittivity of elemental indium. We found that the simulated extinction spectra agree well with the experimentally obtained spectra at 0˚ and 8˚ incidence, despite the polydispersity of the indium pillar height and defects in the hexagonal array.

Our results therefore demonstrate the possibility of realizing large-area fabrication of indium plasmonic nanoparticles, which can be used for plasmonic applications. Given the low-cost and scalable nature of this technique, this work opens new possibilities in the design and fabrication of large-area plasmonic metasurfaces that operate in the UV spectral range. Future extensions of this work may leverage the indium mask-constrained growth to tailor even further the shape of the nanoparticle and hence give a powerful tuning knob to tailor plasmonic resonances.
(Invited) An Overview of Electrochemistry Application to Additive Manufacturing
Authors: Mahajan Chaitanya Gurunath
Published: September 2023

Additive manufacturing (AM) is the process of creating three-dimensional (3D) objects from digital models through the sequential deposition of material in layers. This talk will highlight how researchers have used electrochemical research in additive manufacturing and will provide insights into how technology can be exploited to formulate novel microstructures and optimize the manufacturing process. Electrochemical 3D printing is a relatively new form of AM that creates metallic structures through the electrochemical reduction of metal ions from solutions onto conductive substrates. It involves localized electrochemical deposition of metals combined with additive manufacturing principles to achieve Electrochemical Additive Manufacturing (ECAM). The talk will also focus on the formulation of metal precursor inks to produce novel metallic microstructures and nanoalloys containing multiple metals. These inks are used with AM techniques to fabricate 2D and 3D printed conductive structures directly onto a substrate. Examples include aligned nickel nanowires over large areas, which provide opportunities to produce structures with enhanced anisotropic electrical and magnetic properties. Nanoalloy films printed using metal precursor inks have a variety of important applications involving local control of alloy composition in AM part. Examples include the facile formation of layered nanostructures and electrical conductivity with oxidative stability. The talk will conclude with current research on electropolishing of AM parts. AM while capable of producing complex-shaped metal parts with intricate internal geometries and lattice structures struggles to make parts with the smooth surface finish required for many applications. Polishing interior surfaces inaccessible to traditional surface polishing methods is a challenge. Electropolishing is increasingly being used as a post-treatment option for metal AM parts due to its non-contact nature and ability to finish complex internal features.
(Invited) The Importance of Characterizing and Calibrating Light Engines in Vat Photopolymerization Additive Manufacturing
Authors: Caplins Benjamin
Published: September 2023

Vat photopolymerization (VP) is an additive manufacturing technique that uses spatially patterned light to cure liquid resins into solid materials. As an additive manufacturing technique, parts with complex geometries can be manufactured that would not be possible with conventional techniques. Large scale VP has found wide adoption by a range of industries including automotive, dental, consumer goods, and prototyping. On a smaller scale, hobbyist level users have found innumerable uses for VP and this market, in particular, has fueled the development of a plethora of low-cost printers. Common to all VP printers is the need for a light engine which illuminates the resin and initiates the photopolymerization process. Historically, this light engine was a UV laser with relatively simple optical properties including low divergence, narrow spectral bandwidth, and fixed wavelength – spatial extent of the photopolymerization was controlled by rastering the focused beam across the build plate. More recently, digital micromirror device (DMD) and liquid crystal display (LCD) based light engines have been developed which expose the resin in a parallel fashion by controlling the exposure in a 2-dimensional pixelated manner. These more recent light engine designs tend to rely upon light emitting diodes (LEDs) as the photon source and these have more complex properties including high divergence (i.e. Lambertian emitter), broad spectral bandwidth, and less well-defined wavelength. Many printer manufacturers have developed multi-emitter light engine designs that compound these characteristics. As VP manufacturing continues to mature, the reproducibility of parts, both in terms of dimensional and functional properties, is becoming more and more critical. Here, we present our work on characterizing existing VP printer light engines. We show the types of heterogeneity that are present in these light engines and how they can directly impact printed parts. This then leads us to a discussion about what optical properties are important to control in VP light engines for improved print reproducibility. Finally, we discuss our latest efforts to develop a fully calibrated and characterized uniform light engine for performing careful photopolymerization studies that inform on the underlying photopolymerization physics without convolving light engine heterogeneity with the underlying photophysics.

Figure 1
Operando X-Ray Analyses of NMC811/Li Batteries: Progress Towards Understanding Capacity Fading Mechanisms at High Voltage and Fast Charge
Authors: Quilty Cavlin , West Patrick J , Takeuchi Esther S. , Marschilok Amy C. , Bock David C , Takeuchi Kenneth J.
Published: September 2023

LiNi0.8Mn0.1Co0.1O2 (NMC811) is a commercially successful Li-ion battery cathode due to its high energy density and cyclability. Utilizing this system under fast charge and high potential charge conditions is of great interest as this will help facilitate widespread electric vehicle adoption; however, these aggressive charging conditions lead to enhanced capacity fade. To design next-generation NMC811 batteries with longer life and higher capacity the origins of the capacity fade must be understood. Operando X-ray characterization techniques are critical for this endeavor as they allow the acquisition of information about the evolution of structure, oxidation state, and coordination environment as the material (de)lithiates in a functional battery. Charging to high potential (4.7 V) leads to greater delivered initial capacity but much more significant fading; while fast charging (4C) leads to slightly reduced capacity but with similar fading. Operando XRD and SEM results indicated that secondary particle fracture from increased structural distortions at >4.3 V was a contributor to capacity fade. On the other hand, fast charging led to a slight reduction in structural distortions consistent with the reduced capacity fade. Operando hard XAS revealed significant Ni and Co redox during cycling as well as a Jahn-Teller distortion at the discharged state (Ni3+). Greater bulk redox was observed when charged to 4.7 V while less bulk redox was observed at 4C, consistent with the different delivered capacities. Soft XAS analyses revealed significant surface reconstruction after cycling to 4.7 V. Overall, charging to 4.7 V leads to more structural distortions and particle fracture, as well as surface reconstruction that lead to increased capacity fading. Fast charge does not induce additional structural distortion or surface reconstruction as compared to the slower, moderate charging potential cycling suggesting that the phenomena at the anode may be more critical under fast charge.

References:

Quilty, C. D.; West, P. J.; Wheeler, G. P.; Housel, L. M.; Kern, C. J.; Tallman, K. R.; Ma, L.; Ehrlich, S.; Jaye, C.; Fischer, D. A.; Takeuchi, K. J.; Bock, D. C.; Marschilok, A. C.; Takeuchi, E. S., Elucidating Cathode Degradation Mechanisms in LiNi0.8Mn0.1Co0.1O2 (NMC811)/Graphite Cells Under Fast Charge Rates Using Operando Synchrotron Characterization. Journal of The Electrochemical Society 2022, 169 (2), 020545.

2. Quilty, C. D.; West, P. J.; Li, W.; Dunkin, M. R.; Wheeler, G. P.; Ehrlich, S.; Ma, L.; Jaye, C.; Fischer, D. A.; Takeuchi, E. S.; Takeuchi, K. J.; Bock, D. C.; Marschilok, A. C., Multimodal electrochemistry coupled microcalorimetric and X-ray probing of the
Mechanism, Kinetics and Simulation of Electrocatalytic Oxidation of Dimethylamine Borane (DMAB) on Electroless Gold
Authors: Xue Huize , Sadik Omowunmi
Published: September 2023

Dimethylamine borane ((CH3)2NHBH3) or DMAB, is broadly used as a reducing agent in electroless autocatalytic platings like gold and nickel-boron, hydrogen storage, and reductive amination. However, the mechanism of its DMAB oxidation procedure remains unclear. This project is based on the hypothesis that a multi-step electron transfer mechanism exists for oxidizing the reducing agent DMAB on gold in alkaline media. According to this mechanism, the active species produced when DMAB is used at high hydroxide content is the BH3OH-. This species is created through a series of irreversible electrochemical oxidation producing the following intermediates BH2(OH)2-, BH(OH)3- and B(OH)4-, which is the final product. Multiple electrochemical methods have been used to uncover the properties of DMAB oxidation progress and verify above-mentioned hypothesis. Electrochemical Impedance Spectroscopy (EIS) was used to test the uncompensated resistance between the working electrode and reference electrode and calibrated in the following experiments: Cyclic voltammetry (CV) showed that DMAB in hydroxide electrolytes have three half-wave potentials with E_(1/2) of -0.778, -0.174 and 0.248 V. Kinetic current values obtained from the Koutecky-Levich plot decreased with temperature with -4.065, -3.62 and -1.45 mA/cm2 at 25°C, 41°C and 52°C, respectively. Rotating Disk Electrode (RDE) and Chronoamperometry (CA) were used to determine the Diffusion Coefficient of BH3(OH)-; BH2(OH)2- and BH(OH)3- 1.38E-05, 3.31E-05 and 1.01E-04, respectively. Tafel analysis was used in obtaining the transfer coefficient, whereas Klingler and Kochi’s method evaluated the constant. These kinetic parameters were used in KISSA-1D software to simulate the CVs. Gas Chromatography with Mass Spectrometry (GC/MS) was used to verify the existence of B(OH)4- and a peak at m/z 78.8 was recorded. All of this provided evidence that the three intermediates are involved in the proposed mechanism. In the future, simulated and experimental approaches will be investigated for other amine boranes compounds such as Sodium cyanoborohydride (NaBH3CN), Sodium triacetoxyborohydride (NaBH(O2CCH3)3), and Sodium borohydride (NaBH4). This work will have far-reaching consequences in enhancing the practical applications of gold and nickel in microelectronics and fuel cells.
Fabrication and Applications of Electroplated Three-Dimensional, Open-Cell, Noble Metal Electrodes
Authors: Kazi Abbas Parvez , Routsi Anna Maria , Sullivan Matthew , Christodouleas Dionysios C
Published: September 2023

Noble metal electrodes (Au, Ag, and Pt) have found numerous applications in electroanalysis and electrocatalysis. Noble metal electrodes are typically composed entirely of a bulk noble metal so their cost is high and they have a two-dimensional geometry. This presentation describes the fabrication of inexpensive, electroplated noble metal electrodes that have an open-cell, three-dimensional complex geometry. The electroplated noble metal electrodes exhibit a defect-free layer of a noble metal (i.e., Au, Pt or Ag) deposited onto a copper substrate structure of the desired geometry. The surface roughness of the electrodeposited films was tailored by adjusting the electroplating conditions and the composition of the electroplating solution. The electrochemical performance of the electrodes was fully characterized. The electroplated three-dimensional, open-cell electrodes were used for the detection of heavy metals in aqueous samples and the decontamination of aqueous samples that contained bacteria.
Modeling Mesoporous 3D-Printed Lattice Electrodes for Energy Storage
Authors: Huddy Julia Elizabeth , Tiwari Anand P , Scheideler William Joseph
Published: September 2023

3D printing could offer the versatility to design and manufacture energy storage devices on demand. The precision and material flexibility of 3D printing is ideal for integrating porous electrodes that can enhance electrochemical performance[1]. This work analyzes the electrical conductivity of 3D-printed mesoscale strut lattices at the 100 μm – 1 mm scale with 40 – 90 % volumetric porosity to develop optimal electrodes for energy storage devices. We use a graph-theory-based model[2] to compute the conductivity of multiple 3D lattice types with either solid conducting struts or struts coated with conductive material. These structures show 3 – 5X higher conductivity than random conductive foams that lack an internal periodic mesostructure[3]. Using microstereolithography, we 3D print samples with high-resolution struts (< 70 µm) that maintain their shape and achieve high conductivity after carbonization at 700 ˚C. By tuning the lattice architecture, we manipulate the tradeoff between conductivity, weight, and porosity, validating our simulations with experimental measurements. These results demonstrate that that body-centered cubic (BCC) strut lattices have optimal conductivity per weight compared with other lattice types.

Implementing these 3D-printed conductive lattices as supercapacitor electrodes, we see that the lattice architecture impacts the gravimetric capacitance of the devices as well as the mechanical strength, with octet structures outperforming both cubic and BCC lattices. Electrochemical impedance spectroscopy (EIS) shows that 3D-printed electrodes with higher porosity exhibit higher gravimetric double layer capacitance and lower charge transfer resistance, making them ideal candidates for use in supercapacitor electrodes as free-standing 3D hosts for active materials. CV characterization of the electrodes also illustrates how our graph theory-based model for 3D lattices can predict the optimal structure for energy storage. This model can also serve to predict electrode performance and tailor design for integration of higher surface area nanoporous materials on these conductive 3D printed scaffolds. This allows us to guide the design of 3D printed electrodes to minimize charge transfer resistance and achieve an optimal balance between gravimetric and volumetric energy density for device applications.

[1] J. Zhao, Y. Zhang, X. Zhao, R. Wang, J. Xie, C. Yang, J. Wang, Q. Zhang, L. Li, C. Lu, Y. Yao, Advanced Functional Materials
2019, 29, 1900809.

[2] J. E. Huddy, M. S. Rahman, A. B. Hamlin, Y. Ye, W. J. Scheideler, Cell Reports Physical Science
2022, 3, 100786.

[3] F. G. Cuevas, J. M. Montes, J. Cintas, P. Urban, J Porous Mater
2008, 16, 675.

Figure showing (a) designed octet (blue), cubic (orange), and BCC (red) lattice types as well as (b) SEM images of their experimental 3D-printed counterparts and (c) measured electrical resistance.

Figure 1
Electrochemical Applications of Porous Materials Derived from Coal
Authors: Paul Abigail , Magee Regan , Wichert Nathan , Wilczewski Warren , Trembly Jason , Garrick Taylor R. , Staser John A.
Published: September 2023

As the world shifts from the use of coal to alternatives for electricity generation, including renewable energy, interest arises in developing alternative uses for coal. There are vast U.S. coal reserves, much of which are in historically underrepresented or economically depressed regions. This has created environmental concerns in these regions, especially related to legacy impoundments and other waste coal issues. Finding alternative uses for that coal could create new job opportunities in these regions while also addressing climate change. Currently, there are very few applications for coal outside of its traditional use for electricity production.

This group has been developing alternative uses for coal, including uses in energy storage applications. This presentation will discuss the development of macroporous coal materials that then can be further processed into micron or nanometer size particles for porous materials. The characterization of these porous materials will be presented. Graphitized materials for use in lithium ion battery electrodes will be presented. Nanoscale materials such as graphene and carbon quantum dots derived from coal will be presented, along with their application in porous electrodes for batteries and capacitors.
Development of a New Type of Electrochemical Reactor for Low Temperature Lime and Cement Production
Authors: Loudeche Maxime , Rouxhet Rémy , Proost Joris
Published: September 2023

The cement industry is responsible for more than 8% of the global CO2 emissions, making it one of the largest contributors to global warming. Two-thirds of these emissions are coming from unavoidable process gases caused by the calcination reaction of limestone (CaCO3). The remaining emissions are mainly coming from the combustion of fossil fuels. Due to the high temperature requirement (≈1500°C), direct electrification is difficult to consider. For these two reasons, the cement industry is therefore known as a challenging sector to decarbonize.

A new electrochemical pathway for cement production has gained prominence in the scientific literature in recent years [1]. This technology has the potential to electrify the cement and lime production while producing at the same time valuable gases (O2, CO2, H2). It is based on a new type of hybrid electrolyser capable of working with solid, liquid and gaseous phases. Thanks to the acidity generated by water oxidation at the anode, the solid limestone feed, precursor of cement, is being dissolved. This dissolution produces pure CO2 which is mixed with pure O2 generated by electrolysis and which is easily captured for later use. The calcium ions are then migrating towards the cathode under the effect of the electric field. The OH- hydroxyl ions, produced at the cathode by water reduction, meet the calcium ions to form the final solid product, hydrated lime (Ca(OH)2). This lime can be used as such or converted into cement by additional steps.

In this research, a laboratory-scale setup has been developed to study the feasibility of such a process. Different geometries have been tested and the main operational parameters affecting the different steps of the process have been investigated. Our results show first of all the formation and stabilization of a pH gradient within the electrolyser, which allows at the same time for the complete dissolution of CaCO3 in the acidic anodic environment while producing a white precipitate of Ca(OH)2 at the cathode. The setup also presents ideal faradaic efficiencies when using an IrO2 coated titanium anode and a nickel cathode in a 1M NaClO4 electrolyte. Alternative electrode materials, including a 316L stainless steel anode and an Inconel 718 cathode, have been considered as well. Finally, it was shown that the energetic efficiency can be further improved by pushing the kinetics of the dissolution and precipitation reactions through increasing the mobility of calcium ions, using Ca-based electrolytes, like Ca(ClO4)2. Based on our results, all the elementary concepts behind the hybrid electrolyser have been established, and a first blueprint of a continuous industrial process will be proposed.

[1] - L. D. Ellis, et al. (2019). Toward electrochemical synthesis of cement—An electrolyzer-based process for decarbonating CaCO3 while producing useful gas streams. PNAS
, 117, 12584-12591.

Figure 1
Alternating Current Electrolytic Extraction of Transition Metals from NMC532 using Rotating Disc Cyclic Voltammetry in Dilute Chloride Solution
Authors: Watson Bryce , Carlson Brett , Smirnova Alevtina
Published: September 2023

The rising application of portable electric devices has led to the rapid accumulation of electronic wastes such as lithium-ion batteries. These wastes pose significant environmental threats when improperly disposed of and contain valuable metals that could supplement the supply chain and reduce the need for certain conflict minerals. Recycling methods that limit the potential for environmental damage and improve separation of transition metals are vital to the sustainability of battery based electrical storage. Conventional aqueous recycling of lithium battery electrode materials utilizes oxidizing acids and a chemical reducing agent. This study investigates if chemical oxidizing and reducing agents may be aided or replaced by the application of an alternating electric field to reduce surface metal oxides and subsequently accelerate reoxidation with a solubilizing anion. The electrolytic leaching mechanics of commercial battery cathode material (NMC532) in dilute hydrochloric acid were investigated using rotating disc cyclic voltammetry (RDE-CV), solution analysis with inductively coupled plasma mass spectrometry (ICP-MS), and residue analysis with scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS). We found evidence that applying an alternating electric field allows for adjustment of leaching rates for different transition metals based on electrochemical cell parameters. By applying up to one volt oscillating between reducing and oxidizing polarity, the relative molar leaching rate of nickel and manganese drastically increased while that of cobalt slightly decreased. Future research will be required to determine how this effect translates to different leaching systems and its applicability to an industrial scale process.

The authors acknowledge financial support from the NSF IUCRC program for the “Center for solid-state electric power storage” (#2052631) and support from the South Dakota Board of Regents for the “Governor’s Research Center (GRC) for electrochemical energy storage”.
Perspectives on the Past, Present and Future of Industrial Electrochemistry and Electrochemical Engineering
Authors: Kenis Paul , Mah Dennie
Published: September 2023

This year, 2023, the Industrial Electrochemistry and Electrochemical Engineering (IE&EE) division celebrates its 80th birthday. Since its inception in 1943, these fields have undergone major developments in industrial practice, in fundamental understanding of processes, and in the development of new processes and tools. This contribution seeks to highlight some of these major evolutions over the years, as well as some of today’s developments, with an eye to the future.
Carbon-Based Porous Materials for Energy Storage Applications
Authors: Paul Abigail , Magee Regan , Wichert Nathan , Wilczewski Warren , Trembly Jason , Garrick Taylor R. , Staser John A.
Published: September 2023

Carbon-based materials have many applications in energy storage devices, including batteries and electrochemical capacitors. These materials are sourced from a wide range of raw materials. This project focuses on finding and evaluating electrochemical applications for porous carbon-based materials made from domestic sources. This presentation will focus on our efforts to develop and characterize these porous (at different scales) carbon materials, and on several emerging energy storage applications being investigated at Ohio University. Comparisons with other porous energy storage materials will be made in consideration of process economics and performance.
(Digital Presentation) Polydopamine-Functionalized Bacterial Cellulose As Biopolymer Separator for Lithium-Sulfur Batteries
Authors: Baranwal Rishav , Lin Xueyan , Wang Shu , Fan Zhaoyang
Published: September 2023

Li-S chemistry is regarded as promising next-generation battery technology, but the development of Li-S battery technology is severely impeded by the challenges of polysulfide shuttling and lithium dendrite formation. To address these issues, we coated polydopamine on bacterial cellulose (BC) to create a biopolymer separator. BC provides its dense network, while the presence of polydopamine offers dense polar functional groups to curb polysulfide shuttling by confining them in the sulfur cathode side. Such a separator, with the uniform distribution of nanoscale pores and functional chemical groups, also ensures a consistent Li+ flux at the anode surface, thus addressing the problem of lithium dendrite formation. Our results suggest that this polydopamine/BC-based biopolymer separator has superior performance over the commercial polyolefin-based separator. In particular, the Li-S batteries assembled with this biopolymer separator exhibited a specific discharge capacity of 1449 mAh/g at 0.1C and 909 mAh/g at 1C, while showing a small capacity fade of 0.023% per cycle.
(Invited) Inductive Effects to Control the Operating Voltage of Fast-Charging Molybdenum Oxide Anodes
Authors: Zohar Arava , Wyckoff Kyra E. , Vincent Rebecca , Seshadri Ram
Published: September 2023

Batteries are essential to most modern technologies, as they provide a sustainable alternative to traditional energy sources. One area of active research is in identifying new battery materials made from plentiful elements to produce stable, high power and fast-charging batteries. A candidate for the next-generation anode material is molybdenum oxide, as it shows fast-charging capabilities, stability, and high capacity. The disadvantage of this material is that the expected power is relatively low, as the redox voltage for molybdenum is not optimized to the stability window of the liquid electrolyte. Using the inductive effect as a guiding principle, we suggest lowering the Mo+6/+5 redox voltage by adding a cation to the structure. The structural modification will influence the covalency of the metal-oxygen bond and will therefore allow lower ionization energy (IE) for the d-orbital electrons. To this aim, we compare the electrochemistry of Li2Mo4O13 and MoO3 as well as the IE and the Li diffusivity. The results show that the addition of Li lowers the voltage by 300 mV for Mo+5/+6 compared to MoO3 but does not reduce the Li diffusivity. The change in IE also supports our hypothesis that the Li reduces the polarity of the M-O bond. Additional electrochemical studies indicate limited capacity for Li2Mo4O13 compound, which is related to structural changes after the first lithiation process. Our results demonstrate the utility of exploring new systems with elevated redox voltage to better fit the electrolyte stability window and yield higher power.
Rapid and Reversible Lithium Insertion with Multielectron Redox in the Wadsley-Roth Compound NaNb13O33
Authors: Patterson Ashlea , Elizalde Segovia Rodrigo , Wyckoff Kira , Zohar Arava , Narayan Sri , Clement Raphaele J , Seshadri Ram , Griffith Kent
Published: September 2023

The development of high-performing battery materials is critical to meet the ever-increasing demand for portable energy storage for electronics and electric vehicles. Owing to their exceptionally high-rate capabilities, high volumetric capacities and long lifetimes, Wadsley-Roth compounds are promising lithium anode materials for fast-charging and high-powered devices. This study comprises an in-depth structural and initial electrochemical investigation of the Wadsley-Roth phase NaNb13O33 phase. To our knowledge, this is the first alkali-containing Wadsley-Roth compound tested for lithium insertion.

Here, we report structural insights obtained from combined neutron and synchrotron diffraction as well as solid-state nuclear magnetic resonance (ss-NMR). We find that a variety of simple, solid-state methods reliably produce a ReO6-like base structure with periodic, ”shear” planes of edge-sharing NbO6 octahedra separating 5 x 3 octahedral blocks with square-planar Na+ occupying block corners. Through ss-NMR, we reveal the presence of sodium cations in block interior sites as well as square-planar block sites.

Through combined experimental and computational studies, we demonstrate and rationalize the high-rate performance of this new anode material in lithium-ion half cells. Using X-ray photoelectron spectroscopy (XPS), we show the multi-electron redox of Nb, which enables capacities of 225 mA h g−1 at slow rates and anodic potentials. Without down-sizing or nano-scaling, 100 mA h g−1 of this capacity is retained at 20 C in micrometer-scale particles. By combining bond-valence mapping and DFT, we show that such excellent rate performance results from facile, multi-channel lithium diffusion down octahedral block interiors and from high electronic conductivity within shear planes. Finally, we utilize differential capacity analysis to identify optimal long-term cycling rates and achieve 80% capacity retention over 600 cycles with 30-minute charging and discharging intervals.

Without optimization, these results place NaNb13O33 in the ranks of promising new high-rate lithium anode materials and warrant further research.
(Invited) A Doped Mxene Dual Layer for Reliable Lithium Metal Anode
Authors: Shang Mingwei , Niu Junjie
Published: September 2023

To meet the rapidly growing market in electrical vehicles (EVs) and portable electronic devices, a battery with high energy density is required. In order to reach this goal, Li metal, is considered as the most promising candidate as anode. However, the dendrite forming, low Coulombic efficiency (CE), and unstable solid electrolyte interphase (SEI) pose big challenges in applying Li metal in batteries. Here we introduce a dual-layer coated Li metal surface, which consists a lithium carboxylate organic layer and a doped MXene layer. The porous organic layer increases the wetting of electrolyte and forms a thin solid electrolyte interface (SEI). While the doped MXene leads to about 50% reduced thickness of inorganic-rich components among the SEI layer. A low overpotential of less than 30 mV over 1000 h cycling in symmetric cells was received. The functional groups along with the good electronic conductivity and smooth surface of the MXene greatly reduce the lithium plating/stripping energy barrier, enabling a dendrite-free lithium metal anode. The battery paired with NMC811 exhibited a high initial CE of 82.1%. A high capacity-retention of 175.4 mAh/g at 1.0 C was achieved after 350 cycles. After long 500 cycles, a reliable capacity was still remained while the cell with un-modified Li metal quickly dropped to below 74.2 mAh/g. In a 475 mAh pouch cell, the battery still exhibited a high discharge capacity of 165.6 mAh/g with a capacity retention of 90.2% after 200 cycles, while the cell with pure Li metal decreased to 80.5%.

Keywords: Lithium metal; Battery; Anode; MXene; Doping