bluuebunny/crossref_metadata_2025_split huggingface dataset:
Etidronic Anodizing of Aluminum Alloys: Growth and Properties of Anodic Layers
Authors: Moutarlier Virginie , Daval Jérémy , Brunol Emmanuelle , Viennet Rémy , Ricq Laurence , Hihn Jean-Yves 
Published: December 2024

Anodizing is a well-known electrochemical process used to increase the thickness of the natural oxide present on the surface of aluminum alloys. This process is commonly employed to enhance properties such as anticorrosion and hardness. Sulfuric acid is the most frequent used electrolyte for aluminum alloy anodizing, offering significant corrosion resistance. For applications requiring a hard anodic layer, a specialized sulfuric anodizing can be implemented, where the bath temperature is around 0°C. However, when anodizing is necessary at room temperature, Huang et al. [1] have suggested the use a new electrolyte: etidronic acid (HEDP).
The present work focuses on the study of this new hard anodizing process, with etidronic acid. Electrochemical analyses as well as anodic layer characterizations have been performed for various aluminum alloys including 1050, 2024 and 7075 alloys.
The growth of the anodic layer varies depending on the alloy type. Two modes of anodization have been identified: a conventional anodization mode (for 1050 alloy) and a second mode which can be considered as micro-arc anodization (for 2024 et 7075 alloys). These anodization regimes will induce modifications in the thickness, morphology, crystallinity, and hardness of the anodic layers.
[1] H. Huang, J. Qiu, X. Wei, E. Sakai, G. Jiang, H. Wu, T. Komiyama, Ultra-fast fabrication of porous alumina film with excellent wear and corrosion resistance via hard anodizing in etidronic acid, Surface & Coatings Technology 393 (2020)

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(Invited) A Comparative Evaluation of Li, Na, and K-Ion Cathodes
Authors: Ceder Gerbrand 
Published: December 2024

Most cathode materials for Li-ion batteries are layered oxides which are isostructural to LiCoO2. Other structures, such as spinels, olivines, and disordered rocksalts, can also be used as high-capacity cathodes. The latter three structures types create less resource issues as they can function with Fe or Mn as active transition metals, but still may suffer from resource issues related to Li-ion availability.
With Na, almost all transition metals form layered structures, providing less expensive and more resource abundant options for Na-ion cathodes, but typical layered cathodes have a large voltage slope which limits the usable energy density. The voltage slope is even larger when K is used as an intercalant in layered materials. I will discuss the origin of the voltage slope in these materials and evaluate whether better cathode options are available for Na and K-ion batteries.
(Invited) Garnet Electrolyte Material Degradation and Recovery
Authors: Cheng Lei 
Published: December 2024

Solid state batteries show advantages in battery safety, energy density and temperature tolerance and therefore are considered promising alternative of Li-ion batteries using organic electrolytic solutions. Solid electrolytes are critical components in solid-state batteries. Among different types of solid electrolyte, oxide based, garnet-type Li7La3Zr2O12 (LLZO) solid electrolytes have been of particular interest due to the combination of good ionic conductivity and chemical stability against metallic lithium. However, these materials exhibit surface degradation when exposed to air and moisture, which adversely impacts their functioning in operating solid state batteries.
In this work, multiple depth-profiling techniques were adopted, and the results revealed that a structural and chemical gradient exists upon LLZO degradation. The degradation mechanism of garnet solid electrolyte is discussed with the focus on the surface and sub-surface of LLZO. Based on the understanding, scalable mitigations are developed to recover the degradation by simple treatment at relatively low temperatures.
(Invited) Achieving Extreme High Ion-Current Densities in Tailored Materials, Structures, and Interfaces
Authors: Wachsman Eric D 
Published: December 2024

Oxide-based solid-state batteries have the potential to be a transformational and intrinsically safe energy storage solution due to their non-flammable ceramic electrolyte that enables the use of high-capacity metal anodes and high voltage cathodes for higher energy density over a much wider operating temperature range. However, their progress has been limited due to electrode/electrolyte interfacial issues. In particular for metal anodes concerns over dendrite formation/propagation and the requirement for elevated temperature and high stack pressure are still prevalent. To eliminate these concerns a rational design of tailored materials, 3D structures, and interfaces in metal anodes will be presented. While focus will be on Li-metal anodes we will demonstrate same approach works for Na-metal anodes.
By use of a few nm thin AlOx ALD interfacial layer we were the first to enable Li-metal wetting of LLZO-garnet surface achieving a negligible interfacial ASR of only ~1 Ohm cm2 at room temperature with no applied pressure. Then by fabricating a ~10 mm LLZO dense layer on an extend 3D porous scaffold, with ALD surface modification to enable Li-metal wetting, we were the first to achieve the US DOE VTO Fast Charge goal for Li-metal cycling of 10 mA/cm2 at room temperature with no applied pressure. We subsequently developed a mixed ion and electron conducting (MIEC) garnet composition which when integrated into the 3D porous scaffold structure enabled critical current densities (CCDs) of 100 mA/cm2 and cumulative Li-metal cycling of over 18.5 Ah/cm2 at room temperature with no applied pressure. More recently due to the concern over Li availability we developed higher conductivity NASICON and demonstrated similar stable cycling of Na-metal in 3D structured NASICON achieving CCDs of 30 mA/cm2 at room temperature with no applied pressure.
These new solid-state compositions integrated into surface modified 3D structures enable previously unheard-of metal-anode cycling rates. Their development and progress toward full cells using these tailored materials, structures, and interfaces will be presented.
The Mechanism of Cu Microvia Pulse-Reverse Electrodeposition in Single Accelerator System
Authors: Seo Huiju , Kim Myung Jun , Kim Jae Jeong 
Published: December 2024

As device miniaturization approaches its limits in terms of performance enhancement, the importance of efficiently arranging devices and the technology for connecting each device, known as packaging, is increasing. In packaging, interconnects are used to connect devices, and Cu electrodeposition is widely employed to form these interconnects. To achieve defect-free interconnects, typically three types of additives are used: accelerator, suppressor, and leveler. However, using various additives increased the complexity of electrodeposition bath monitoring system. In the PCB industry, where plating baths are used for periods exceeding six months, the complexity of process management due to the use of various additives becomes further increased.
In this study, Cu microvias used as interconnects on PCB are plated using a SPS single accelerator system, within 60 minutes. To achieve defect-free filling, a pulse-reverse current waveform was introduced instead of direct current. Also, the behavior due to differences in convection was analyzed to suggest a mechanism capable of inducing superfilling. After the reverse time, Cu+ forms on the surface, and due to the Cl- rich surrounding environment, Cu-Cl species covers the surface. This CuCl layer is known to assist the adsorption of SPS, accelerating the electrodeposition process. Inside the vias where convection is weak, CuCl remains, leading to an acceleration effect by SPS. However, outside the vias where strong agitation is present, CuCl with adsorbed SPS is flown away into the bulk, resulting in the acceleration effect being observed only within the inside of the vias. In this study, the presence or absence of an acceleration effect depending on convection was confirmed through electrochemical results, and this has been proposed as the mechanism for single accelerator system superfilling.

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(Invited) Cu-Cu Bonding in Semiconductor Packaging: Utilizing Texture Control for Enhanced Performance
Authors: Han Haneul , Yoon Sanghwa , Yoo Bongyoung 
Published: December 2024

The rapid development of IT markets, including big data, AI, 5G, IoT, smart automotive, and datacenters, has led to an increase in demand for advanced packaging solutions. With the IC density doubling through the shrinking of feature sizes, significant improvements in IC device performance have been achieved. This continuous scaling of feature sizes has prompted changes in packaging technology, with three-dimensional die stacking technologies like through-silicon vias (TSVs) and microbumps emerging as crucial innovations.
However, traditional microbumps suffer from issues such as the Kirkendall effect, side wetting, and solder depletion, which compromise both mechanical and electrical properties. Innovative solutions are thus essential to address these challenges effectively. Cu to Cu bonding eliminates the formation of intermetallic compounds, mitigating the problems associated with microbumps. Additionally, Cu to Cu bonding offers superior electrical properties compared to microbumps, further enhancing its appeal.
In particular, semiconductor devices requiring high-density packaging, like high bandwidth memory (HBM), have spurred interest in hybrid bonding. Additionally, the growing need for 3D interconnects in advanced packaging is becoming increasingly apparent.
To this end, research is focusing on next-generation microbumps, particularly Cu-Cu bonding, as an alternative solution. Understanding the internal characteristics of Cu is crucial for promoting diffusion between Cu atoms at lower temperatures. Thus, nanotwinned Cu with a (111) preferred orientation has garnered significant research attention as a material that promotes diffusion between copper atoms, particularly in Cu-Cu bonding processes. However, research is lacking on the optimal grain orientation for the bonding process.
By controlling crystal orientation through plating parameter adjustments, Cu films with three principal preferred orientations have been achieved. These films exhibit distinct mechanical properties based on their preferred orientation, with (111) preferred Cu showing the highest hardness due to the significant presence of nanotwins.
In summary, advancements in 3D interconnect technologies, particularly in Cu-Cu bonding, hold promise for addressing the challenges in advanced packaging. By employing innovative solutions and exploring new materials and techniques, the semiconductor industry can continue to meet the evolving demands of the IT market while ensuring the reliability and performance of semiconductor devices.
(Invited) Mechanics of Materials in All Solid-State Lithium Metal Batteries
Authors: Warren Roseanne 
Published: December 2024

All solid-state lithium metal batteries (ASSLBs) with ceramic solid electrolyte and lithium metal anode are promising candidates for next-generation, high energy density batteries. Unlike conventional lithium-ion batteries with liquid electrolyte, ASSLBs present a ceramic-metal interface at the anode that is prone to various mechanical failure modes, including: non-uniform plating causing cracks in the solid electrolyte and the anode current collector; non-uniform stripping creating gaps between anode and electrolyte; and cracking and void formation leading to dendrite growth, short-circuits and capacity loss. As such, the mechanical properties of the ceramic solid electrolyte, lithium metal, and anode current collector are critical parameters affecting cell performance.
This talk will explore the mechanical properties of interest for ASSLBs and their influence on cell charge-discharge behavior. Methods of characterization of these properties across length scales will be discussed, including recent work on instrumented indentation testing (nanoindentation, scanning electron microscopy with in-situ picoindentation) and a novel in-situ straining technique with transmission electron microscopy. The ability to influence mechanical properties of the anode-solid electrolyte interface through changes in process parameters will also be described. Overall, the methods and results presented here will provide a picture of the role of mechanics in ASSLBs and highlight pathways to greater understanding.
Electrochemical Studies of Tricosafluorododecanoic Acid (TCFDA) and Perfluoroundecanoic Acid (PFUDA)
Authors: McGhee Saniya , Ridgeway Madison , Workie Bizuneh 
Published: December 2024

Per- and polyfluoroalkyl compounds (PFCs) are anthropogenic industrial chemicals widely used in applications like surface coatings, surfactants, and flame retardants. These compounds have become emerging contaminants due to their persistence and resistance to degradation in the environment. PFCs are known for their environmental stability, which allows them to remain in air, water, and soil for extended periods. As a result, they have been detected globally in water, soil, wildlife, and even in human bodies. Their recalcitrant nature poses a significant environmental concern.
One potential solution for mitigating PFC contamination involves their decomposition through oxidation or reduction methods. Cyclic voltammetry (CV) studies have shown that certain per- and poly-fluoroalkyl substances (PFAS), such as Tricosafluorododecanoic Acid (TCFDA) and Perfluoroundecanoic Acid (PFUDA), are reducible. These studies were conducted in acetonitrile (CH3CN) with tetrabutylammonium hexafluorophosphate (TBAHFP) as the supporting electrolyte. CV experiments were performed with a 5.00 mM solution of TCFDA and PFUDA over a voltage range from 1.20 V to -1.20 V, using platinum as the working electrode and Ag/AgCl, KCl (satd.) as the reference electrode. The results indicated similar major cathodic and anodic peaks for both compounds, though the peaks showed variations in potential and height.
In addition to CV studies, exhaustive electrolysis of TCFDA and PFUDA in TBAHFP–CH3CN confirmed the decomposition of these compounds, producing new intermediate compounds. The findings from this research provide valuable information that could contribute to the development of electrochemical methods for decomposing PFAS, particularly TCFDA and PFUDA, in wastewater. This approach could offer a promising treatment strategy to reduce the environmental persistence and impact of these compounds.
Investigating (photo)-Electrochemical Pathways for the Remediation of Co-EDTA Wastewater Streams
Authors: Wu Jhen-Cih , Su Xiao , Hou Chia-Hung 
Published: December 2024

The discharge of heavy metals into water bodies has dramatically increased due to the rapid expansion of industrial and human activities, posing severe threats to ecosystems and human health. This pressing issue is exacerbated by the presence of chelators like EDTA and its heavy metal complexes (HMCs), which hinder the effectiveness of conventional water treatment methods. These chelated heavy metals possess stable structures and high environmental mobility, making the remediation of heavy-metal-contaminated wastewater streams significantly challenging. In recent years, cobalt has become increasingly favored for interconnects and contacts in semiconductor manufacturing due to its lower resistivity and superior resistance to electromigration compared to copper. This shift has led to a noticeable accumulation of cobalt-EDTA (Co-EDTA) in waste streams, particularly from chemical mechanical polishing (CMP) processes. Despite systematic investigations into the decomplexation of copper-EDTA (Cu-EDTA) and nickel-EDTA (Ni-EDTA), research focusing on Co-EDTA removal and its destruction pathways using (Photo)-EAOPs remains lacking.
This study aims to explore the (photo)-electrochemical performance of a tailored TiO2-encapsulated electrified membrane for Co-EDTA remediation. Under both electrocatalysis (EC) and photo-electrocatalysis (PEC) conditions, the electrified membrane exhibited significant efficacy in degrading EDTA-Na2, highlighting its potential in chelator decomposition. The addition of UV-LED light further enhanced the kinetics of EDTA-Na2 removal. Cobalt complex decomposition rates reached approximately 45-50%, with PEC demonstrating superior efficiency. Furthermore, varying cathode voltages revealed notable impacts on Co-EDTA decomplexation and cobalt recovery. The experimental findings also emphasized the role of electrolyte concentration in optimizing total cobalt and total organic carbon (TOC) removal rates. To validate the practical application of the system, we simulated a municipal wastewater treatment scenario spiked with 0.5 mM Co-EDTA, demonstrating the feasibility of the electrified membrane system. This research showcases the potential of (Photo)-EAOPs in effectively mitigating heavy metal complex contamination in real-world wastewater treatment settings.
Fabrication of Uniform Porous Anodic Aluminum Oxide by Anodizing Aluminum in Trisodium Phosphate with Higher pH Values
Authors: Hsieh Hsuan-Lin , Terashima Ayasa , Kikuchi Tatsuya 
Published: December 2024

Anodizing of aluminum is an electrochemical process of surface oxidation to form an alumina layer. Porous anodic aluminum oxide (PAAO) possessing self-organized nanopores can be obtained by anodizing aluminum in several acidic electrolyte solutions, and it has been widely used to develop emerging applications, such as nano-filters and optical devices. Recently, we found that anodizing in several alkaline solutions caused the formation of PAAOs with unique nanostructures such as an extremely high porosity and ultra-flat barrier layer. However, the anodizing process in alkaline solutions with higher pH values produced a slightly non-uniform film due to the active dissolution environment of alumina. Herein, we report the fabrication of uniform PAAO film by anodizing aluminum in alkaline solutions and their unique nanostructures.
High-purity aluminum specimens were electropolished in 78 vol% CH3COOH/ 22 vol% - 70% HClO4. The electropolished specimens, then, were anodized in a 0.3 M trisodium phosphate (Na3PO4) solution at 274 K (pH = 13.1) and a constant voltage of 2-100 V. A platinum plate was used as the cathode, and the aluminum specimen was placed parallel to and 22 mm from the platinum plate. We investigated the effect of various operating conditions on the formation of PAAO film. The growth behavior and internal structure of anodized specimens were examined by optical microscopy (OM), field-emission scanning electron microscopy (FE-SEM), and scanning transmission electron microscopy (STEM).
Figure 1a shows the OM images of the aluminum specimen anodized in a 0.3 M Na3PO4 solution at 274 K and a constant voltage of 20 V for 60 min with and without stirring the solution. A non-uniform appearance with both weak white and metallic luster areas was obtained on the specimen anodized with stirring, whereas a uniform metallic luster can be observed without stirring. The SEM images of four different surface positions (2 mm intervals) of each anodized specimen are shown in Figure 1b. In the case of the stirring condition, the surface of PAAO on the left was dissolved due to the high pH value of the Na3PO4 solution and higher dissolution rate caused by stirring. On the other hand, a uniform PAAO film possessing similar nanoscale pores was successfully fabricated by suppressing non-uniform dissolution without stirring. The PAAO film grew by anodizing in the Na3PO4 solution at extremely low applied voltages less than 10 V.

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Electropolishing of Magnesium and Its Alloys in Highly Safe Sodium Chloride/Glycol Solutions
Authors: Tomita Shunsuke , Kikuchi Tatsuya 
Published: December 2024

Magnesium and its alloys are expected to be used in various engineering fields, such as automobiles, trains, and electronic product enclosures due to their lightness and mechanical properties. Electropolishing of magnesium surfaces is an important technique for fundamental research works and industrial applications, and perchloric acid or nitric acid is typically used for electropolishing. However, these acids are highly reactive and hazardous, thus the usage should be avoided in the industrial application processes. In this study, we demonstrated a highly safe electropolishing process of magnesium using a novel sodium chloride/glycol solution.
High-purity magnesium plates (99.95 wt%, 1 mm thick) were used as the starting materials. The specimens were ultrasonically degreased in ethanol for 10 min. The magnesium specimen as the anode and a platinum plate as the cathode were immersed in four types of glycol solutions including 0.5 M NaCl/ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TrEG), and tetraethylene glycol (TeEG) solutions at 278-308 K, and linear sweep voltammetry (0.1 Vs-1) and constant voltage electrolysis (25-100 V) were carried out. After electrolysis, the surface of the specimens was examined by stereo microscopy (SM), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The regular reflectance from the magnesium surfaces was measured using a spectrophotometer. Two types of industrial magnesium alloys including Mg-Al alloy, AZ31, and Mg-Li alloy, LZ91, were also used for electrolysis.
As the voltage-current curves were measured by linear sweep voltammetry of the pure magnesium specimen in four types of glycol solutions, clear diffusion limiting currents were obtained after the initial current increases. We found that the unevenness of the magnesium specimens decreased by constant voltage electrolysis at appropriate applied voltages in NaCl/DEG and NaCl/TeEG solutions. Figure 1a shows the surface appearances of pure magnesium, LZ91, and AZ31 after constant voltage electrolysis at 50 V in NaCl/DEG solution for 60 min. The pure magnesium specimen and LZ91 alloy were successfully electropolished by constant voltage electrolysis and mirror-finished surfaces were obtained. On the other hand, the AZ31 alloy exhibited a nonuniform appearance with the coexisting of metallic luster and brownish regions, although a mirror-finished surface was obtained. The difference of the electropolishing behaviors between LZ91 and AZ31 alloys may be due to the metallographic structure such as the solid solution and intermetallic compound. Three-dimensional magnesium specimens possessing the curved and spiral structures could also be electropolished by constant voltage electrolysis in NaCl/DEG (Fig. 1b).

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