bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrodeposited Ni-Fe-TiO2 Alloy Composites As a Bifunctional Electrocatalyst for Alkaline Water Splitting Reactions
Authors: Annadurai Sreenivasan , Podlaha Lisa J
Published: December 2024

The hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) that governs electrolytic water splitting are of interest as a way to store energy from renewable sources. However, replacing noble metal electrocatalyst with those comprised of lower cost, earth abundant elements remains a challenge as these materials impart a higher overpotential, and hence energy requirement, to both reactions. Guided by the recognized enhanced activity of Ni-based hydroxides in alkaline media,1 and known enhancements of TiO2 in Co-Mo alloys for HER, the examination of Ni-Fe-TiO2 alloy composite electrocatalysts are explored.2

Nano-scale TiO2 particles were embedded into Ni-Fe alloys by using galvanic and pulse-reverse electrodeposition, onto rotating cylinder electrodes. Pulse-reverse electrodeposition considerably increased the concentration of the particles incorporated into the alloy. The composition and morphology was characterized by x-ray fluorescence (XRF) spectroscopy and scanning electron microscopy (SEM), respectively. The addition of particles to the electrolyte affected both the deposit composition and morphology. The alloy composites were then used as electrocatalysts in 1 M KOH to characterize HER and OER via linear sweep voltammetry on the resulting hydroxide surface. The surface area was examined in a ferri/ferrocyanide electrolyte. The polarization data in 1 M KOH shows a significant reduction in the HER overpotential when TiO2 particles are present in the Ni-Fe deposit. The surface analysis of Ni-Fe and Ni-Fe-TiO2 confirmed that the improvement in HER activity is not due to surface roughness but an intrinsic one. The OER rate was not significantly altered by the included TiO2 particles in the deposit. Stability of the electrocatalysts under an electrolysis for HER and an independent electrolysis for OER was examined.

References

M. I. Jamesh. J. Power Sources
333, 213 (2016); A. Eftekhari. Int. J. Hydrog. Energy
42, 11053 (2017); J. Zhao, J-J. Zhang, Z-Y Li, X-H Bu, Small, 16 2003916 (2020).

C. Wang, H. K. Bilan, and E. J. Podlaha. J. Electrochem. Soc. 166 F661 (2019). C. Wang and E. J. Podlaha, J. Electrochem. Soc. 167, 132502 (1~4) (2020).
Nucleation and Growth during Electrochemically Induced Deposition of Li3PO4
Authors: Saleh Ali Amir , De Taeye Louis , Patnaik Sai Gourang , Vanheusden Genis , Vereecken Philippe M.
Published: December 2024

The field of electrochemically induced depositions has been gradually gaining a lot of attention in the last few decades due to the unique abilities it offers, namely the thin film deposition of insulating materials on a conductive surface [1]. While direct electrochemical methods can be used to deposit redox active species, their use in depositing insulating materials is limited as some insulating materials are redox inactive. One of these redox inactive insulating materials is Li3PO4. In the synthesis of Li3PO4 thin films a local pH increase near the electrode surface, by the electrochemical reduction of water, triggers the precipitation. Due to the surface confined nature of the diffusion layer, the OH- concentration near the surface will be significantly higher than in the bulk and phosphate near the surface will react with the hydroxides to form the deprotonated species, which in the presence of lithium ions will precipitate. This process can be visualized in Figure 1.

In this work, we have studied the nucleation and growth of electrochemically induced Li3PO4 deposition combining experiment and model. We developed a model to calculate the concentration profiles of the different species in the diffusion layer, which is then used to predict the point at which the solubility product is surpassed at the surface and in the near surface diffusion layer. This allows the prediction of the influence of the reaction parameters such as current density, bulk pH, lithium concentration, and initial phosphate concentration on the supersaturation. To further improve the accuracy of the model, turbidity experiments were performed to determine the effective solubility product of the system. The model was combined with the experiment to link supersaturation with seed density and understand the effect of current density and time on island density, size and precipitation rate. It is shown that, as for the case of direct electrodeposition where island density is function of overpotential (supersaturation), a direct correlation can be made between supersaturation and island density, supporting the classical nucleation and growth theories also for electrochemically induced deposition.

Figure 1
: Schematic representation of the electrochemically induced deposition of Li3PO4 with water as a probase.

References:

[1] Walcarius, A., Sibottier, E., Etienne, M. et al. Electrochemically assisted self-assembly of mesoporous silica thin films. Nature Mater
6, 602–608 (2007). https://doi.org/10.1038/nmat1951

Figure 1
Electrochemical Atomic Layer Deposition: Self-Terminated Electrodeposition Reactions
Authors: Kim Hyunki , Liu Yihua , Lafouresse M , Stafford Gery R , Moffat Thomas P
Published: December 2024

Recently, an inexpensive “wet form” of ALD based on self-terminated electrodeposition reactions was uncovered that enables controlled formation of ultrathin films of Pt, Ir and iron group metals and alloys thereof. Common to all these systems is the role of reaction intermediates, namely adsorbed H in the quenching of metal deposition reactions. Further details on the mechanisms of self-terminated deposition reactions will be discussed. Likewise, the utility and relevance of the process to the synthesis of nanoparticles and thin films, and the study of bimetallic electrocatalysts will be detailed.
Evaluation of Copper Sulfate Electroplating Solution and Film Quality Prediction Using Turbidity Measurement Method
Authors: Koga Toshiaki , Sakata Yoshitaro , Terasaki Nao
Published: December 2024

Measuring and controlling the condition of the plating bath on the production line is important to achieve high quality plating and automation of the manufacturing process. Proper evaluation of plating solution degradation is one of the most pressing challenges in the copper sulfate electroplating process. However, constant monitoring and evaluation on the production line is difficult, and periodic sampling is used for evaluation. Optical measurement would be a simple and accurate method with which to achieve on-time and in-situ evaluation.

We have developed a method to optically measure monovalent copper (Cu(I)) in a copper sulfate electroplating solution to evaluate the deterioration of the solution. Bathocuproinedisulfonic acid, disodium salt (BCS) specifically reacts with Cu(I) and forms an absorption band in the visible light region. By measuring its absorbance, it becomes possible to quantify the Cu(I) concentration in the aqueous solution. Absorbance measurement using BCS is a technology that can easily quantify Cu(I), making immediate measurement possible at production sites.

Color reaction measurements are simple and suitable for production line applications, but like other methods, sampling is required. Furthermore, we proposed a method to evaluate plating solutions using fluorescence. This measurement detects the generation of fluorescence due to the decomposition of additives originally contained in the plating solution. There is no need to add special chemicals, and the state of the solution can be measured on the spot without sampling. However, this fluorescence is only effective when using Janus Green B (JGB) as an additive.

On the other hand, light scattering can detect the formation of microparticles in solution. It is known that the accumulation of copper fine particles due to disproportionation reactions affects the quality of copper sulfate electroplated films. This suggests that the production of copper fine particles in the plating solution increases the light scattering intensity and can serve as an indicator of the degree of turbidity of the solution.

In this study, we used a fluorometer to measure the intensity of light scattered in the direction perpendicular to the incident light as an indicator of the turbidity of the plating solution, and verified the relationship between the formation of fine particles due to energization and the increase in turbidity. This is equivalent to measuring turbidity using nephelometry. Furthermore, we will clarify the relationship between turbidity and Cu(I) accumulation and its effect on plating film quality, and consider its application to plating solution evaluation.

Figure 1
(Invited) Understanding Catalytic Structure-Function Relationships via in-Situ Surface Stress Measurements of Electrodeposited Metal Films
Authors: Raciti David , Stafford Gery R , Moffat Thomas P
Published: December 2024

Ultrathin Pt films are emerging as promising catalysts for fuel cells and water electrolyzers, offering improved utilization of the costly metal and enhanced performance through catalyst-support or alloying interactions. Properly matched to a substrate, Pt overlayers exhibit significantly enhanced catalytic properties attributed to changes in electronic and geometric properties induced by the substrate, including d-band shifts influenced by lattice misfit strain. This talk reports will focus the ability of in-situ stress measurements to offer real-time insight into stress development during Pt overlayer electrodeposition on secondary metal supports. Moreover, these measurements are also used to enable monitoring of stress-based events during the catalytic application of electrodeposited films. For instance, in the electrochemical conversion of organic molecules, carbon monoxide (CO) serves as a pivotal intermediate, particularly in the oxidation of oxygenated hydrocarbons in fuel cells. Understanding changes in stress during CO adsorption and oxidation using these films facilitates empirical correlations between structure and function, driving the development of superior electrocatalysts crucial for advancing towards a circular carbon-based economy.
(Invited) Electrodeposited Oxides and Catalysts for Photoelectrochemical and Electrochemical Water Splitting
Authors: Jang Ho Won
Published: December 2024

Electrodeposition with a long history has been considered one of the important synthesis techniques for applying various applications. It is a feasible route for fabricating nanostructures using diverse materials due to its simplicity, cost-effectiveness, flexibility, and ease of reaction control. Herein, we mainly focus on the nanoscale electrodeposition with respect to dimension control and three-dimensional (3D) conformality. We introduce that manipulating synthesis parameters such as precursors, applied current/voltage, and additives affect the synthesis reaction, resulting in not only dimensional control of materials from three-dimensional structures to zero-dimensional atomic-level but also conformal coatings on complicated substrates. This talk represents significant advances in the nanoscale synthesis of oxides and catalysts for photoelectrochemical and electrochemical water splitting.
Bottom-up Gold Filling of Curved X-Ray Gratings
Authors: Josell Daniel , Raciti David , Gnaupel-Herold Thomas , Moffat Thomas P , Romano Lucia , Rawlik Michal , Chen Liyang , Yu Qihui , Stampanoni Marco , Pereira Alexander , Stauber Martin
Published: December 2024

Over the past five years an electrolyte-additive system has been demonstrated and applied to void-free extreme bottom-up filling of high aspect ratio etched silicon structures that are key to advanced grating-based X-ray interferometry. Effective use of the full area of the gratings with conventional X-ray sources requires they have a finite radius of curvature to align the high aspect ratio Au-filled trenches with divergent X-rays. With that in mind, this presentation details bottom-up Au filling in gratings attached to curved holders as in the accompanying figure. Contactless mapping of the Au-filled gratings, also shown in the figure, captures residual (i.e., intrinsic) curvature that is retained after their release from the curved holders. X-ray diffraction quantifies the elastic strains in the Si underlying the Au-filled trenches of the grating. Complementary measurements on the surfaces of unpatterned Si wafers mounted on curved holders are used to understand the curvatures actually imposed in the mounted gratings. Both intrinsically curved gratings and gratings that have been re-bent toward their radius while mounted provide high visibility across the entire field of view of an X-ray interferometer for bio-medical imaging applications. They also have internal strains substantially below those in planar gratings bent to the same radius.

Figure 1
Sustainability in the Electroplating Industry: A Challenge to Overcome
Authors: Innocenti Massimo , Giurlani Walter , Rosini Alfredo , Marcucci Manuele , Bonechi Marco , Verrucchi Margherita , Biffoli Fabio , Pappaianni Giulio , Mariani Elena , Giovani Claudia , Fontanesi Claudio
Published: December 2024

The interest in scientific research in the metal-finishing sre is constantly growing. The market demand for durable metal coatings and adaptable manufacturing processes is increasing across a wide range of applications, from aerospace and automotive to machinery and jewelry. An essential step in the production line is the surface engineering of metal deposition, as this determines the final appearance and functionality of the final industrial/handcrafted product. Therein electroplating is recognized as a mature technology allowing for the low-cost fabrication of well-defined surfaces, with extensive property profiles. Galvanic electrodeposition accounts today for almost 40% of the global market value share of the metal-coating market, with North America and Western Europe leading the scenery. Although technological and processing advancements occurred in the past forty years, industrial firms are still struggling to provide solutions to corrosion protection as well as the reduction of toxic wastes. Specifically, large-scale industrialization of electroplating techniques will continue to be limited by strict environmental regulations. Environemental rules and regulations got more and more strict, and sustanability issues will further push for more restrictions concerning the industrial impact on the environment. Due to adverse ecological implications, the adoption of plating processes involving toxic metals such as lead or cadmium is prohibited. Moreover, price volatility of the highly demanding electroplated materials gold, copper, and nickel is expected to impact the market share by more than 60% by 2026. In that respect, alloy plating offers better answers in terms of economic growth and environmental sustainability, allowing for fine-tuning composition, morphology, and crystallinity [1]. In this paper, current trends in alloy electrodeposition research are reviewed highlighting open challenges and process innovations from an industrial perspective. The main categories of alloy compounds are presented, and the most important characteristics of the manufacturing process are critically discussed. With particular focus on advances in industrial quality-control and viable solutions for the reduction of precious metal content in electroplated accessories, as well as the replacement of cyanide and nickel baths with processes featuring non-toxic compounds. In particular, the use of pulsed currents, new alloy formulation acting as a barrier layer and the reduction of defective pieces are the novel strategies/solutions to increase the sustainability of production processes in the electroplating industries.

References

[1] W. Giurlani, M. Innocenti et all. , Electroplating for Decorative Applications: Recent Trends in Research and Development, Review, Coatings 2018, 8(8), 260.
(Invited) Molecular Thermoelectricity
Authors: Yoon Hyo Jae
Published: December 2024

The field of molecular thermoelectricity focuses on the Seebeck effect occurring in electrode-molecule-electrode junction. The field is of fundamental interest to study structure-thermopower relationship at the atomic level and develop nanoscale thermoelectric devices. Research in molecular thermoelectricity is highly challenging. This is because, among others, i) heat can dissipate in an uncontrollable manner through nearly all matters, ii) it is difficult to create and define reliably temperature differentials across ~1 nm gap, iii) organic molecules may undergo thermal degradation, iv) it is non-trivial to connect soft, floppy organic molecules with hard electrodes in a non-invasive manner with reproducibility, and v) charges move in a quantum-mechanical regime. This presentation will discuss our recent efforts in the field of molecular thermoelectricity. We have developed a new metrology technique for reliably measuring Seebeck coefficient over molecular monolayers. Using this technique, we have begun to probe how thermopower is related to the structure of molecule and how to enhance the thermoelectric performance of molecular-scale device in a quantum-tunneling regime.
Electrodeposited NiFeCo + Tb and Dy for Enhanced Magnetostrictive Properties and Soft Magnetism
Authors: Faltas Mina , Rodriguez Mark , Soule Luke , Meyerson Melissa L , Oglesby Skyler , Jackson Nathan , Pillars Jamin R. , Elkady Ihab
Published: December 2024

Magnetostrictive thin films have numerous applications in communications, sensors, and microelectronic devices. Such devices usually require magnetostrictive thin films with large magnetostriction and soft magnetic properties. Nickel-Iron-Cobalt alloys can be easily fabricated as thin films in addition to having excellent soft magnetic properties. Their main drawback for these sensing applications is that they have very low magnetostriction. On the other hand, Iron-Rare Earth (RE) alloys such as Fe-Tb-Dy or Fe-Ga have large magnetostriction at the cost of some soft magnetic properties. We report the development of Nickel-Iron-Cobalt thin films with incorporated rare earth elements with large magnetostriction and soft magnetic properties. The combination of these properties makes these NiFeCo thin films with added Tb and Dy excellent candidates for developing resonant frequency communication devices.
Electrochemical Methods to Optimize Anodic Aluminum Oxide and Incorporation of Molybdenum Disulfide for Enhanced Wear Performance
Authors: Hooks Daniel E , Hatfield Kendrich , Brown Nathan , Dervishi Enkeleda , Carpenter Bradley , Janusz Jordyn
Published: December 2024

Anodized aluminum oxide (AAO) has many beneficial properties leading to its wide use across industries as a surface treatment for many aluminum components, but the wear properties of the coating could be improved significantly. Here, we used an electrochemical method to incorporate molybdenum disulfide (MoS2), a nanomaterial used as a dry lubricant, to modify alloys of aluminum during AAO preparation. Using Raman spectroscopy and tribological scratch measurements, we thoroughly characterized the structure and wear behavior of the films. The MoS2 deposition procedure was optimal on aluminum 5052 anodized in higher acid concentrations, with friction coefficients around 0.05 (~10x better than unmodified AAO). Changing anodization conditions to produce harder films with smaller pores led to worsened wear properties, likely because of lower MoS2 content. Studying a commercial MoS2/AAO film of a different Al alloy (7075) showed that a heat treatment step intended to fully convert all deposited MoSx species to MoS2 can adversely affect wear in some alloys. While Al 6061 and 1100 produced films with worse wear performance compared to Al 5052 or 7075, our results show evidence that acid cleaning after initial anodization likely removes residual alloying elements, affecting MoS2 incorporation. This study demonstrates a nanomaterial modified AAO film with superior wear characteristics to unmodified AAO and relates fabrication procedure, film structure, and practical performance. Methods for production of this enhanced wear coating for several aluminum alloys along with associated wear and scratch performance will be presented.
Towards the Electrodeposition of Graded Polymer / Metal Composites
Authors: McBride Michael , Rutledge Amanda , Hatfield Kendrich , Hooks Daniel E
Published: December 2024

In high pressure physics applications, a shock wave can be modified by tuning the acoustic impedance of an impactor. The acoustic impedance is influenced by the sound speed of the material and the density. Forming structures that have a gradation in these properties enables a range of experiments to better understand materials under extreme conditions. Polymers are some of the lowest density materials with densities around 1 g/cc. The density of metals extends from ~1 g/cc to ~ 20 g/cc. Thus, being able to create graded polymer / metal structures maximizes the gradation of density.

Electropolymerization can be used to deposit polymer films on a surface. Polypyrrole can be synthesized from pyrrole in nitric acid via the electrochemical formation of the oxidizing nitrosyl ion. Metallic electrodeposition occurs via the reduction of metal salts. Therefore, careful control of the applied currents using pulse electrodeposition methods can be used to co-deposit both species. The challenge is in controlling the growth mechanisms.

Early observations indicated that polymers could nucleate from existing polymer chains or metallic surfaces. Metallic nucleation could only occur from metal sites, resulting in dendritic metallic structures decorated with polymers. Efforts to control the nucleation and growth dynamics to encourage more layer-by-layer growth are currently on-going. Herein, we will present our findings in controlling the microstructures of electrodeposited polymer / metal composites.
(Digital Presentation) Co-Nanocatalysts in the Reaction of Electrochemical Reduction of Nitrates to Ammonia
Authors: Kuznetsova Irina , Kultin Dmitry , Lebedeva Olga , Kalmykov Konstantin , Kustov Leonid
Published: December 2024

Electrocatalytic methods for producing ammonia from nitrates represent a promising and environmentally friendly alternative to the traditional Haber-Bosch synthesis.

An important criterion for assessing the efficiency of a reduction reaction is the Faraday efficiency of the reaction. It is determined by the choice of catalyst electrode and its properties.

Nanocatalysts offer advantages over conventional metal catalysts by increasing catalyst activity by controlling particle size and reducing catalyst production costs.

Currently, the electrocatalytic activity of metal cobalt, its oxides, and mixed catalysts based on it are being actively studied. In this study, the electrocatalytic ability of electrodeposited and metallic cobalt in the reduction of nitrate to ammonia was investigated. The nanocatalysts were synthesized by electrodeposition of cobalt onto a graphite substrate from an aqueous solution of sodium sulfate at a deposition time of 5–30 min. The surface of the resulting catalysts represents a dense and thin layer of cobalt particles with a diameter of 20-100 nm.

The efficiency of nanocatalysts was assessed using Faraday efficiency (FE) data. The best results for electrodeposited cobalt were 50 to 60% FE. The electroreduction reaction of nitrates deserves further study and discussion of its prospects for industrial application.

Further research will be aimed at optimizing reaction conditions and developing new electrocatalysts with high efficiency and selectivity, including the addition of particles of other metals to cobalt (Fe, Cu, Ni).

Figure 1
Lithium-Ion Intercalation By Coupled Ion-Electron Transfer Mechanism
Authors: Zhang Yirui , Fraggedakis Dimitrios , Gao Tao , Pathak Shakul , Stephens Ryan , Bazant Martin Z. , Shao-Horn Yang
Published: December 2024

Ion intercalation in intercalation solids is crucial for energy storage device, including Li-ion batteries. Despite significant advancements in understanding Li-ion diffusion and discoveries of new electrodes and electrolytes, the molecular process of ion intercalation across electrode-electrolyte interfaces remains poorly understood. Li intercalation kinetics has been traditionally treated by the empirical Butler-Volmer kinetics, but remains poorly measured and understood. In this study, we developed experimental electrochemical methods to probe Li+ (de-)intercalation kinetics, and provided unique experimental evidence to support the microscopic mechanism of Li+ intercalation, described by the coupled ion-electron transfer mechanism. Current-voltage responses and reaction-limited capacities, indicative of small and large overpotentials, respectively, were measured across various electrode materials, including common LixCoO2 and NMCs, and were consistent with the proposed theory. A universal dependence of the intercalation rate on the lithium-ion filling fraction was revealed, as well as temperature and electrolyte effects, consistent with the theoretical description that classical ion transfer from the electrolyte is coupled with quantum-mechanical electron transfer from the electrode. Our findings suggest that the proposed mechanism applies to a variety of intercalation materials used in energy storage, and governs the power density at low and moderate applied current densities. The possibility of modifying the reaction-limited current with electrodes and electrolytes opens new directions for interfacial engineering of Li-ion batteries.
New 3D Current Collectors for Lithium-Ion Batteries
Authors: Hamankiewicz Paulina , Rogulski Zbigniew , Ratyński Maciej , Grygiel Michał , Czerwiński Andrzej , Hamankiewicz Bartosz
Published: December 2024

Lithium-ion batteries are among the most modern energy sources for consumer electronic devices. Each reversible lithium cell consists of components responsible for delivering charge and electrochemically inactive materials. The active components of a lithium-ion cell include electrode materials (such as graphite and lithiated cobalt oxide) and electrolyte. These compounds participate directly in the electrode reactions, generating the voltage and energy supplied by the battery. In addition to electrochemically active materials, lithium-ion cells contain several components that are not electrochemically active but perform important functions in the battery. Such components include the outer casing, internal and external leads, the separator, and the copper (for the negative electrode) and aluminium (for the positive electrode) current collectors. Current collectors are essential components connecting lithium-ion batteries to external circuits. They serve as a matrix that holds the active material in a mechanically stable form and are also involved in dissipating the charge generated by electrode processes. Thus, current collectors largely determine the capacity, performance, and long-term stability of lithium-ion batteries. Conventional current collectors, aluminium and copper foils, have been used since the first commercial lithium-ion battery. They account for about 15 percent by weight of the total cell, and because they are inactive components of the battery, there is a continuing need to reduce their mass share without losing functionality. Over the past two decades, in order to increase the energy density of lithium cells, the thickness of current collectors has decreased significantly. However, to further improve performance, alternative materials and structures are being explored, as well as specific collector treatments such as etching or carbon coating. These treatments aim to enhance the electrochemical stability and electrical conductivity of current collectors for the next generation of lithium-ion batteries with higher capacity and longer life. The presentation will review various types of current collector materials in terms of their electrochemical stability, electrical conductivity, mechanical properties, and durability. It will also include alternatives to traditional structures, such as 3D current collectors. Two types of three-dimensional current collectors will be presented: a 3D structure on a copper film collector and conductive porous carbon. The electrochemical properties of lithium-ion batteries utilizing these collectors will be demonstrated.
The Mechanism of Redox-Mediated Li2O2 Oxidation and 1O2 Evolution in Li-Air Batteries
Authors: Dewar Daniel , Ahn Sunyhik , Zor Ceren , Yang Sixie , Nimmo Tammy , Kibler Alexander , Gao Xiangwen , Johnson Lee R , Bruce Peter
Published: December 2024

The lithium-air (Li-O2) battery has the highest theoretical energy density (3500 Wh kg-1) of any rechargeable battery. Modelling has suggested more than 600 Wh kg-1 may be possible for the whole system, including air handling, making Li-O2 attractive for the electrification of aviation.(1) However, the development of the Li-O2 battery has faced many challenges since its inception, such as degradation and slow kinetics.(2) The discharge product at the cathode is Li2O2, which is electronically insulating and difficult to oxidise on re-charging.(3) To overcome the difficulties of direct electrochemical reactions involving an insulating solid, redox mediating molecules (RMs) were introduced such that the Li2O2 is formed and oxidised in the electrolyte solution in the pores of the cathode.(4) On charging the cell, the RM is oxidised at the surface of the cathode, and then diffuses to and oxidises Li2O2 within the cathode pores, releasing O2. It is desirable for the RM to operate at as low a voltage as possible, above the thermodynamic oxidation potential of Li2O2, to maximise energy efficiency during cycling.

In our recent work, we have investigated the mechanism by which RMs oxidise Li2O2 particles.(5) The trend of oxidation rate with mediator potential follows Marcus theory with a maximum rate at +3.74 V. We show that following the initial outer-sphere one-electron oxidation of Li2O2, the dominant subsequent step is the disproportionation of LiO2 to 3O2, and not the one-electron oxidation of LiO2 to 1O2 or 3O2 (Fig. 1). We also show how RMs with different potentials affect the 1O2 yield and that this does not correlate well with degradation, casting doubt on whether 1O2 is the major source of degradation during charge. Our mechanism not only explains why the current generation of mediators cannot deliver high charging rates at sufficiently low potentials for good round-trip energy efficiency but also points the way to designing mediators that can deliver high rates at low charge voltages.

W. J. Kwak, et al., Chem Rev, 2020, 120, 6626-6683.

S. A. Freunberger, et al., Angew Chem Int Ed Engl, 2011, 50, 8609-8613.

V. Viswanathan, et al., J Chem Phys, 2011, 135, 214704.

Y. Chen, et al., Nat Chem, 2013, 5, 489-494.

S. Ahn, et al., Nat Chem, 2023, 15, 1022-1029.

Figure 1
(Invited) Understanding Compatibility of Layered Oxides in Solid State Batteries
Authors: Besli Muenir M. , Metzger Michael , Usubelli Camille , Hellstrom Sondra , Liu Yijin , Nordlund Dennis , Doeff Marca M. , Christensen Jake , Kuppan Saravanan
Published: December 2024

The compatibility (chemical, mechanical and thermal) of Ni Rich layered oxide cathode materials are influential factors that critically affect the performance and durability of solid-state batteries. This presentation will discuss, the chemothermal stability of layered oxides in relevant operating temperatures of polymer solid-state batteries using synchrotron-based absorption spectroscopy. We observe Ni oxidation state change on the surface, subsurface, and in the bulk of layered oxide particles depending on the formulation and operating conditions. In addition, we will also discuss, the impact of mechanical stability of layered oxides on SOC (state of charge) inhomogeneity in the cells cycled in solid polymer batteries. This presentation will review our fundamental understanding of chemo-thermo-mechanical breakdown of the layered oxides in solid-state polymer batteries.
High Performance Electrolytes for Lithium-Sulfur Batteries
Authors: Cao Xia , Kautz David J. , Shi Lili , Xiao Jie , Liu Jun , Lu Dongping , Xu Wu , Zhang Ji-Guang
Published: December 2024

Lithium-sulfur (Li-S) battery is one of the most promising energy storage systems owning to their high energy density and cost-effective sulfur source. However, their practical application is still hindered by challenges such as the severe shuttle effect of lithium polysulfides (LiPS) and severe lithium corrosion that lead to substantial self-discharge and rapid capacity degradation. An advanced electrolyte is critical to unlock the full potential of Li-S batteries. This work reports a new type of electrolytes to enhance the performance of the Li-S batteries. These electrolytes have low-LiPS-solubilities to minimize the LiPS shuttle, therefore suppressing battery self-discharge. In the meanwhile, these electrolytes demonstrated enhanced lithium stability and improved the cycling stability of the Li-S batteries. In addition to advancing electrolyte development, the study delves to comprehensive postmortem characterizations, providing a deeper understanding of the inherent failure mechanisms of the Li-S batteries. These fundamental insights elucidate the reasons for the improvements enabled by the advanced electrolyte developed in this work. These insights can also serve as guidelines for the future design of advanced electrolytes tailored for further improvement of Li-S batteries and other Li batteries.
Small Molecule Aromatic Hydrocarbons: Powering Ultralong Cycle Life in Li-Ion Battery Anodes and Dual Chemical Prelithiation for Li-Ion Capacitors
Authors: Su Yu-Sheng , Arya Avi , Lai Kuan-Lin
Published: December 2024

Exploring the potential of Small Molecule Aromatic Hydrocarbons (SMPAHs) such as naphthalene (Naph), biphenyl (BP), 9,9-dimethylfluorene (DiMF), phenanthrene (Phen), p-terphenyl (p-Ter), and pyrene (Py) reveals their exceptional performance as promising candidates for lithium-ion battery (LIB) anodes. These SMPAHs offer high specific capacities, remarkable cycle stability, and excellent rate capabilities. Investigation into their electrochemical behavior demonstrates superior long-term cyclability, with capacity retention exceeding 92% after 1500 cycles and a Coulombic efficiency approaching 100%. However, the study identifies the challenge of pyrene dissolution, which leads to poor capacity due to irreversible structural collapse caused by the vertical expansion of the pyrene dimer, resulting in the dissolution of pyrene into the electrolyte.

In parallel, SMPAHs drive advancements in lithium-ion capacitor (LIC) technology through a facile dual chemical prelithiation approach. Among them, the LIC cell with the Li-BP solution prelithiated hard carbon anode and activated cathode exhibits the highest energy density of 98 Wh/kg at 0.5C and retains 47% of reversible capacity at 20C, establishing it as one of the best-performing LICs reported to date. Notably, precise control of prelithiation level in AC cathodes is crucial to prevent unwanted lithiation and corrosion of aluminum. This integrated approach propels the evolution of electrochemical energy storage toward a greener and more efficient future.

Figure 1
Aging Analysis for Li Metal Batteries Exposed to Calendar and Non-Uniform Use Conditions
Authors: Dufek Eric J. , Barnes Pete , Kim Sangwook , Chen Bor-Rong , Zhang Hongxing , Efaw Corey M. , Wang Yulong , Park Bumjun , Li Bin , Evans Michael , Mak Bianca , Liaw Boryann , Olds Daniel , Khalifah Peter G. , Hodges Brittany
Published: December 2024

Lithium metal batteries have seen dramatic advancement over the last 5 years. In realistic cell designs the ability to achieve both high energy and long cycle life have been demonstrated using constant current cycling. Based on the observed performance the timing is right for more detailed analysis of some of these promising systems in more realistic use cases including calendar aging and using interspersed charge and discharge pulses which mirror vehicle acceleration and regeneration. In a combination of studies it has been found that shifts to these use cases present both significant promise for the current technical approaches as well as distinct challenges which will need to be addressed for future implementation in long range, high performing electric vehicles.

This discussion will focus on a few of these key findings and present options to continue the advancement of high energy Li metal batteries.
Microfluidic Device for in Situ Observation of Bottom-up Copper Deposition in a TSV-like Structure- Improved Adhesion of Working Electrode Edge
Authors: Zhu Yize , Hayase Masanori
Published: December 2024

The high performance of modern integrated circuits is now owing to packaging technologies. 3d-packaging using TSVs (Through Silicon Vias) has attracted large attention. Copper electroplating is used for filling conductor into the vias, because extreme bottom-up is available using a combination of additives. Even though extreme bottom-up is available with single addition of leveler without other additives and theoretical model, such as S-NDR model proposed by Moffat and Josell, can predict the filling behavior, still combination of leveler, suppressor and accelerator is generally used in industry and filling mechanism with the combination is not clear yet. To understand the mechanism of copper filling and the function of each additive, we have proposed microfluidic devices. In our previous study, a TSV-like structure was built in a micro channel as shown in figure 1, and real-time observation of copper bottom-up deposition was demonstrated. Though the observation was successful, observation period was limited to short periods of time, because abnormal deposition occurred at mouse of the TSV-like structure.

In this study, we assumed that poor adhesion around the edge of the working electrode on a substrate caused the abnormal deposition, because insufficient adsorption of leveler is expected if the working electrode thin film was floating from the substrate. Then, fabrication process of the working electrode was changed from etching to lift-off patterning technique. Several processes were optimized and abnormal deposition along the edge was successfully suppressed as show in figure 2. Using the lift-off technique, a TSV-like structure was built and electrodeposition was examined. Electrodeposition was started at 30 s after feeding a plating solution containing the leveler. Results are shown in figure 3. No abnormal deposition around the opening of TSV-like structure more than 10 min, and we succeeded in the observation of suppression breakdown inside the via. Further study with various combination of additives will be planned.

Figure 1
Aerosol Jet Printing, Electrodeposition, and Passivation Process for Fabrication of Flexible Rhenium Interconnects
Authors: Manzi Jacob , Tsui Lok-kun , Ma Zhefan , Ahammed Kamal , Huang Qiang , Lavin Judith Maria
Published: December 2024

Additive manufacturing (AM) is an adaptable and cost-effective method in both rapid prototyping and the fabrication of flexible electronic components. Aerosol jet printing (AJP), a direct write printing technique, can print features down to 10 microns in size. When combined with electroplating, AJP can pattern materials not directly printable. Here, we use this approach for developing flexible interconnects for quantum computing applications. Current quantum computers are limited by rigid coaxial cables configured in low densities where the interconnects can suffer from significant joule heating due to their resistance. A novel solution to this problem is to fabricate the interconnects from a superconducting material operating below its critical temperature, which will not exhibit joule heating and can be arranged in more dense configurations. Rhenium (Re), a superconductive material with a critical temperature of 6K, can be electrochemically deposited (ECD) onto a conductive trace. In this instantiation, we investigate the ECD of Re onto aerosol jet-printed test structures. Herein, we demonstrate the printing and sintering of gold (Au) onto polished flexible polyimide substrates followed by the electrochemical deposition of Re. The corrosion of Re was found to occur in the presence of oxygen and water. To prevent Re corrosion, it is necessary to passivate the Re surface. Here, two candidate materials were investigated: SU-8 and Norland Optical Adhesive (NOA). The Kapton-Au-Re-NOA/SU8 samples were subjected to environmental testing to evaluate the performance of the passivation layers by observing signs of visual corrosion and measuring electrical performance. Cyclic bend tests were conducted to evaluate the mechanical flexibility of the material stack. The passivation of Re deposited onto AJP gold and the flexibility of the materials without failure were successfully demonstrated. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525
The Future of Die-to-Die Copper Interconnects and Epoxy Dielectrics
Authors: Park Junghyun , Dauda Monsuru Olatunji , Bello Mustapha , Flake John C.
Published: December 2024

Recent Die-to-Die (D2D) interconnects require high data rates operating at high frequencies (> 10 GHz) in multichip packages. Mechanical adhesion was utilized to improve the reliability of traditional packages by increasing interface roughness between epoxy dielectrics and electrochemically deposited copper interconnects. The classical packages, operating at low frequencies below 1 GHz, showed a negligible scattering of electromagnetic waves (S21 < 0.5 dB/m) on the rough surface [1, 2]; however, recent interconnects present considerable degradation in power losses (S21 > 1.0 dB/m) on the rough surface due to skin effect at high frequencies (> 10 GHz) [2]. While previous works have shown the impact of surface roughness on adhesion enhancement, a trade-off between adhesion and power losses has not been precisely considered.

This study investigates the trade-off between reliability and performance. We explore the impact of surface roughness on adhesion and power efficiency of electrochemically deposited copper interconnects at high frequencies up to 18 GHz. Wet etching was performed to modify surface roughness for low-cost production. The root-mean-square roughness (RRMS) is regulated at ~10-100 nm to examine smooth copper-epoxy interfaces for future D2D interconnects. The surface morphology is analyzed by atomic force microscopy (AFM). Adhesion and insertion losses are investigated by peel test and vector network analyzer. A direction for future work is provided to improve chemical adhesion at a smooth copper-epoxy interface. Chemical adhesion is expected to improve the reliability of future multichip packages while maintaining power integrity. For example, surface oxidation and silane coupling agents are discussed to improve chemical adhesion at the smooth interface (< 100 nm RRMS).

REFERENCES:

[1] Lau, J.H., Recent Advances and Trends in Advanced Packaging. IEEE Transactions on Components, Packaging and Manufacturing Technology, 2022. 12(2): p. 228-252.

[2] Gold, G. and K. Helmreich, A physical surface roughness model and its applications. IEEE Transactions on Microwave Theory and Techniques, 2017. 65(10): p. 3720-3732.
(Invited) Processing, Mechanics, and Electrode Structure for All-Solid State LLZO Batteries
Authors: Tucker Mike C , Go Wooseok , Jonson Robert A , Shen Fengyu , Doeff Marca M.
Published: December 2024

LLZO (Li7La3Zr2O12) and related garnet materials are primary candidates for the electrolyte and electrode scaffold of all-solid state lithium batteries. LLZO is a ceramic oxide with a wide voltage stability window, good conductivity at room temperature, and chemical compatibility with a wide variety of electrode active materials. Implementation of LLZO in full cells with high energy density is challenging, however, due to Li loss during sintering, reaction with transition metal cathodes at elevated processing temperatures, high volumetric density that limits cell energy density, brittle mechanical failure, and lithium intrusion into the electrolyte during cell operation at high current density. This presentation will summarize our efforts to address these issues through advancements in processing, mechanical properties, electrode structure, and composite electrode material selection.

To enable high energy density, it is desirable to utilize a thin (<100 μm) LLZO electrolyte layer. High conductivity of the thin electrolyte is maintained by adding sacrificial lithium carbonate, which compensates for lithium evaporation during sintering. Adding MgO prevents abnormal grain growth and maintains the desired fine grain structure, leading to a ~70% increase in fracture strength. Preparing a thin, flexible green ceramic sheet via tapecasting allows the electrolyte to be laminated to a porous LLZO electrode scaffold, or shaped via texturing prior to sintering. Scaffolds are prepared by high shear compaction, phase inversion, freeze tape casting, and other processing techniques based on scalable tape casting. In the case of texturing, surface features are impressed into the green LLZO tape and the additional surface area of the sintered LLZO surface decreases interfacial resistance and increases critical current density from 0.2 to 0.5 mA/cm2.

Utilizing these optimized ceramic fabrication processes, solid state cells are prepared with ~80 μm thick LLZO electrolyte, no added liquid electrolyte, and no exogenous pressure. A catholyte comprising organic ionic plastic crystal and a mixture of lithium salts is melt-processed to achieve good wetting and interfacial contact between the rigid LLZO and NMC cathode active material. This cell design achieves ~180 mAh/g and stable cycling for >100 cycles at room temperature. Efforts to scale up the cell size and improve rate capability will also be discussed.
Understanding the Electrochemistry of Solid-State Lithium-Oxygen Batteries Under Humid Environments
Authors: Lee Jaeheon , McCloskey Bryan D.
Published: December 2024

Lithium-air batteries (LABs) represent a promising future battery technology due to their high energy density, although several challenges hinder them from achieving their theoretical performance. However, aprotic electrolyte-based LABs face several operational challenges, perhaps with the most severe being the instability of aprotic electrolytes towards reactive O2 species, nucleophilic attack, and auto-oxidation.1,2 Compared with aprotic electrolyte-based LABs, organic-free molten salt LABs showed improved oxygen efficiency but required high temperatures to operate the system.3 Alternatively, inorganic solid state electrolytes could not only enable room temperature and stable performance, but also protect Li metal electrodes from reaction with common air components, such as nitrogen, oxygen, CO2, and H2O.

Recently, a solid state Li-O2 battery was found to form LiOH as the major discharge product when humidity was introduced into the oxygen feed stream.4 Our aim is to understand the influence of humidity on the discharge product composition, as well as the reversibility of the full discharge-charge cycle. To do so, we developed a controlled-humidity Differential Electrochemical gas monitoring system, which controls and monitors humidity in the cell headspace while also tracing overall gas consumption and evolution. We will report on solid-state batteries that employ NASICON-type and garnet-phase ion conductors paired with either carbon or MnO2 cathodes. Our initial results suggest that the discharge product formed is a combination of Li2O2 and LiOH depending on the humidity and cathode composition used. On charge, while oxygen evolution is observed whenever Li2O2 is formed, little O2 evolution is observed from LiOH, suggesting a parasitic reaction involving LiOH and cell components.

References

S. A. Freunberger et al., Angewandte Chemie - International Edition, 50, 8609–8613 (2011).

J. Lai et al., Angewandte Chemie, 132, 2994–3019 (2020).

V. Giordani et al., J Am Chem Soc, 138, 2656–2663 (2016).

M. Kim et al., Sci Adv, 8 (2022).

Figure
1. Schematic diagram of Solid-State Lithium-Air Batteries under a humid environmen

Figure 1