bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulating Zinc Electrodeposition on the Anode By Controlling Crystal Growth
Authors: Zhang Duhan 
Published: December 2024

Ensuring the reversible electrodeposition of metals at liquid-solid interfaces is crucial for the long cycle life of rechargeable batteries that employ metals as anodes. While extensive research has focused on the electrochemical transformations influencing reversibility, the fundamental hurdles related to maintaining morphological control when an intrinsically crystalline solid metal phase emerges from an electrolyte solution have received less attention. However, these challenges present significant opportunities for advancement.
Here, we propose a method to stabilize crystal growth and reshape the initial growth and orientation of crystalline metal electrodeposits. This approach leverages polymer-salt complexes (PEG-Zn2+-aX−) (where a = 1,2,3) spontaneously formed in aqueous electrolytes containing zinc (Zn2+) and halide (X−) ions to regulate electro-crystallization of zinc. Specifically, we demonstrate that when X = Iodine (I), these complexes facilitate the electrodeposition of zinc in a hexagonal closest packed morphology, with the (002) plane preferentially oriented parallel to the electrode surface. This precise control over zinc electrodeposition morphology on planar substrates leads to exceptional anode reversibility and unprecedented cycle life. We validate the practical benefits of this approach through studies on Zn-I2 full battery cells, implemented in both coin cell and single-flow battery cell configurations.
(Invited) Hard X-Ray Core Shell Spectroscopy Studies of Battery Materials
Authors: Balasubramanian Mahalingam 
Published: December 2024

Understanding the charge compensation mechanisms during electrochemical cycling of battery materials is of both fundamental and applied interest. X-ray Absorption Fine Structure (XAFS), an element specific probe of the projected, unoccupied density of states as well as the local and medium-range structure around the probed photoabsorbing atom, has been a workhorse technique that sheds light on the atomic and electronic structure of the metal ions. However, the rising edge at the metal K-edge — the energy of which is used in assigning oxidation state — also depends on other factors such as the nature of the ligand, covalency, coordination number, and metal spin-state. We have recently show that by coupling XAFS with Resonant X-ray Emission Spectroscopy (RXES), questions concerning metal oxidation state and site symmetry can be addressed, even in highly covalent systems [1]. In this talk, we will highlight the application of these hard X-ray spectroscopy methods to understand fundamental structure-function relationships of materials and systems relevant to lithium-ion batteries. The first topic of the talk will address the redox mechanisms and migration tendencies in an earth-abundant Li1.3Mn0.5Fe0.2O 2 cathode material (see figure below). In the second topic, we will examine the evolution of the electronic structure of nickel and dopant ions (cobalt) in a nickel-rich material.
[1] Redox Mechanisms and Migration Tendencies in Earth-Abundant 0.7Li2MnO3·0.3LiFeO2 Cathodes: Coupling Spin-Resolved X-ray Absorption Near Edge and X-ray Absorption Fine Structure Spectroscopies, C.Y. Kwok, S. Mallick, C. J. Pollock, A. Gutierrez, M. Dixit, J. R. Croy, and M. Balasubramanian, Chemistry of Materials 2024
36 (1), 300-312

Figure 1
(Invited) Are There Still Gold Nuggets on the Sandy Beach? Efforts to Further Reducing the Cost of Li-Ion Batteries through the Discovery of Low-Cost New Cathodes
Authors: Liu Zhantao , Zhao Simin , Tang Yuanzhi , Zhu Ting , Chen Hailong 
Published: December 2024

The cost of lithium-ion batteries (LIBs) has undergone a remarkable reduction, decreasing by approximately an order of magnitude over the past 15 years, from around $1000/kWh to approximately $130/kWh today, following an exponential curve. However, achieving further cost reductions to around $20/kWh within the next 10-15 years is extremely challenging. Despite significant efforts over the past decade or so to decrease the use of expensive Co in LIBs, such as transitioning from NMC111 to NMC811 or NMC9055, semi-expensive Ni is still heavily used, and the manufacturing cost associated with the high-temperature synthesis of layered oxides remains largely unchanged. The manufacturing expense is also a factor in the high cost of LiFePO4, which only comprises abundant elements but requires expensive carbothermal synthesis and carbon coating.
There appears to be a long quiet period in the discovery of new intercalation-type cathodes following the successful development of LiCoO2 (1979), LiMn2O4 (1984), LiFePO4 (1997), and the NMC family (1990s). To date, no cathode material for rechargeable LIBs beyond those listed above has been commercialized on a large scale. Here we present the recent discovery of a novel, low-cost intercalation cathode that demonstrates very good performances in an all-solid-state configuration and shows significant potential for commercialization. When paired with a competitive solid electrolyte, this cathode material displays two flat voltage plateaus averaging at 3.65 V, an impressive initial capacity of 159 mAh/g, a high energy density of 580 Wh/kg, and stable cycling. Characterizations via neutron diffraction and X-ray absorption spectroscopy reveal that the Li+ storage mechanism is associated with a topotactic intercalation-deintercalation reaction associated to a Fe2+/Fe3+ redox couple during cycling. Most importantly, this cathode material costs only 2% of LiFePO4 and 1% of LiCoO2, holding tremendous promise for commercial applications, particularly in large-scale energy storage such as grid storage.
Numerical Strategy to Optimize Barrel Electroplating : Discrete Element Method and Electrochemical Modeling
Authors: Fedi Baptiste , Marchais Kevin , Schoenleber Jonathan , Boucher Aurélien 
Published: December 2024

Electroplating barrel processes are widely used, particularly for corrosion protection of small components like screws, or gold plating applied to micro components. Achieving uniform coating for all parts is essential, requiring the identification of optimal parameters such as applied current, barrel rotation speed, or charge rate. The main goal is to maximize anode exposure times and reduce the risks of shocks or part sticking, which can result in heterogenous thickness distribution and aesthetic defects. Traditionally, the definition of optimal process parameters is on empirical approaches, with inherent limitations. This conference aims to present how complementary simulation methods can enhance the identification of optimal processing conditions, focusing on two key aspects.
The first aspect involves modeling the electrochemical kinetics of the process to understand the current distribution due to the geometry part itself and predict thickness distribution or alloy composition in the case of an alloy.
The second aspect explores the use of granular simulation with the Discrete Element Method (DEM), leveraging the computational power of GPU technology. Although DEM is known for its high computational cost, advancements in GPU computing have made it feasible to distribute computations across multiple cores, enabling faster simulations with larger particle counts. This is particularly beneficial for simulating barrel finishing processes, where complex shapes such as screws or bolts need to be accurately represented. By simulating the movement and interactions of these particles within the barrel, it can be possible to explore mixing dynamics and optimize charge rates to improve treatment uniformity.
To validate the numerical models developed using these simulation methods, reduced-scale experimental tests are conducted. A 3D printed transparent drum is used to facilitate tracking of particle movement and interactions during the treatment process. This experimental validation provides crucial insights into the accuracy and reliability of the numerical models, ensuring that the simulated results align with experimental observations.
We will also discuss numerical aspects and challenge in order to link DEM mixing results with electrochemical modeling.
The results of this study enable reduction of quality defects with mixing and charge rates during electrolytic barrel treatment. The combination of electrochemical modeling and granular simulation allows for a better understanding of the link between process parameters and coating properties (thickness, composition...).
In conclusion, the integration of advanced simulation methods offer potential numerical help to increase efficiency and reduce non-quality of barrel electroplating processes.
Optimization of Oxygen Reduction Activity Via Transition Metal-Oxide Based Composite Electrodes in Acidic Medium
Authors: Park Hyeonji , Han Kyeongwon , Kim Hyungjin , Song Jeongeun , Ko Yuri , Jeon Yukwon 
Published: December 2024

Global warming has occurred due to the usage of fossil fuels and greenhouse gas emissions. Therefore, a change in the energy paradigm can overcome the problems of global warming and air pollution and provide new energy to humanity continuously. Fuel cells are an eco-friendly system that utilizes the electricity generated during the process of producing water from hydrogen fuel. In general, 20 wt% Pt/C is used as the commercial catalyst for polymer electrolyte fuel cells (PEFCs), but challenges remain to solve such as cost and durability. In PEFCs, oxygen reduction reaction (ORR) is an important key as a rate-determining step (RDS) to react the overall reaction. Therefore, it is necessary to develop efficient materials (electrode, membrane, cell, etc.) for improving RDS. Recently, transition metal oxide (TMO) composite electrodes have gained interest in the electrochemical fields. Especially, nickel, cobalt, iron-based oxides are promising materials as non-noble metal electrocatalysts due to their high electric conductivity and various oxidation state.
The purpose in this research is to improve ORR performance by controlling active sites and electric conductivity using low amount of noble metals on transition metal doped oxides for the use at the electrode. We have developed composite oxide electrodes with noble-transition metal alloy using solid-state methods. Small amount of noble metal can be alloyed with transition metal to form appropriate oxygen binding energy for oxygen adsorption and desorption, which can improve ORR activity. To check the catalytic activity, cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were analyzed using a rotating disk electrode, and it was found that the noble metal-transition metal alloy oxide composite electrode was effective in enhancing the ORR kinetics. Additionally, the strong interaction between the alloy nanoparticles and oxide support surface enhances chemical stability when used in harsh environments such as acidic media. Furthermore, based on the previous ORR data, we fabricated membrane electrode assembly (MEA) using developed catalysts and confirmed their potential for PEFCs applications.
Eco-Friendly and Cost-Effective Electrochemical Synthesis of High-Purity Lithium Hydroxide Monohydrate
Authors: Kim Hyun-Jong , LIM Hana , Park Sung Cheol , Oh SeKwon , Lee Ho-Nyun , Son Seong Ho 
Published: December 2024

In recent years, lithium compounds have been seen as energy materials of great commercial value as the global energy industry develops. The use of lithium-ion batteries (LIBs) in electric vehicles (EVs) is driving the global demand for lithium resources. While many studies have shown that EVs have environmental benefits over internal combustion engine vehicles, the impact of battery production is still uncertain. We need to dramatically reduce greenhouse gas (GHG) emission from the LIBs manufacturing process and raw battery material production.
Typically, lithium compounds have been produced from hard rock minerals or continental brines. The former consumes large amounts of sulfuric acid and is more energy-intensive and expensive than the latter. When extracting lithium from conventional brine, we first produce technical-grade lithium carbonate (Li2CO3), which can then react with calcium hydroxide to produce battery-grade lithium hydroxide (LiOH·H2O). In the LCA study, the GHG emissions of producing Li2CO3 from brine were found to be between 2.7 and 3.1 tonne CO2e/tonne Li2CO3, while the GHG emissions of producing LiOH were more than twice as high, between 6.9 and 7.3 tonne CO2e/tonne LiOH·H2O. Therefore, there is a need to further reduce greenhouse gas emissions from the LiOH manufacturing process.
In this study, we developed an eco-friendly and cost-effective process for producing high purity LiOH·H2O from Li2CO3 solution using a membrane-based water electrolysis reaction. This process significantly reduces the energy consumption of the LiOH manufacturing process. We investigated the impact of various operational variables on process efficiency, including solution concentration, current-voltage, and flow rate. The mechanism of LiOH synthesis, the role of membrane, and greenhouse gas emissions will be discussed.
(Invited) Admittance Analysis to Evaluate Carbon Steel Corrosion Covered with Rust Layer in Electrochemical Impedance Spectroscopy
Authors: Hoshi Yoshinao , Akimoto Yusaku 
Published: December 2024

An electrochemical impedance spectroscopy (EIS) has been used for the corrosion evaluations of steel materials because it allows the time constants observed in the impedance spectrum to be discriminated1. The impedance response of steels covered with rust layer was reported to investigate the conditions of rust layer. Kihira et al.2 applied EIS to investigate the properties of rust film formed on the weathering steel. They proposed the diagnosis method for the rust stability test based on the ion transmission resistance and the thickness of rust layer. Nishikata et al.3 employed EIS for the monitoring of corrosion rate of steels in atmospheric corrosion. Nishimura et al.4 examined the formation of rust film on the carbon steel under wet and dry corrosion tests by EIS. Itagaki et al.5 applied EIS to investigate the electrochemical properties of rust film membrane of low-alloy steels. Katayama et al. 6 reported the effect of rainfall on atmospheric corrosion of carbon steel by impedance monitoring. These results indicated that the corrosion rate of steels was strongly related to the quality of rust film formed on steel. The determination method of the corrosion rate of steel materials covered with rust layer is required for the safety management in the steel structures.
In the present study, we investigated the impedance characteristics of carbon steel covered with rust layer and evaluated their corrosion rate from the admittance spectra. The atmospheric exposure test was conducted to form the rust layer on the carbon steel for several years. We will introduce the impedance spectra of carbon steels covered with rust layer and the relationship between the impedance of samples and the exposure time. We will discuss the determination method of polarization resistance from the admittance spectra of samples to estimate the corrosion rate of samples.

References

M. E. Orazem, B. Tribollet, Electrochemical Impedance Spectroscopy, Wiley (2008).

H. Kihira, S. Ito and T. Murata, Corrosion, 45, 347 (1989).

A. Nishikata, Y. Yamashita, H. Katayama, T. Tsuru, A. Usami, K. Tanabe and H. Mabuchi, Corros. Sci., 37, 2059 (1995).

T. Nishimura, H. Katayama, K. Noda, T. Kodama, Zairyo-to-Kankyo, 49, 45 (2000).

M. Itagaki, R. Nozue, K. Watanabe, H. Katayama, K. Noda, Corros. Sci., 46, 1301 (2004).

H. Katayama, K. Kiyoizumi, I. Shitanda, M. Itagaki, Y. Tsutsumi and Y. Murase, Tetsu-to-Hagané, 107, 1004 (2021).
Atomic Layer Deposition Silver for Hydroxide Exchange Membrane Fuel Cells
Authors: Seo Beum Geun , Prinz Fritz , Shim Joon Hyung , Han Gwon Deok 
Published: December 2024

The transition to e-mobility to achieve zero-emission targets has spurred the market growth of fuel cell electric vehicles (FCEVs) as one of the clean transportation means. Proton exchange membrane fuel cell (PEMFC) have been widely used as an electric propulsion system for hydrogen-fueled FCEVs. However, the electrochemical reaction of PEMFC, which produces electricity from hydrogen fuel in an acidic environment where the use of platinum group metals (PGM) is essential, is a major obstacle to improving cost and performance competitiveness. Hydroxide Exchange Membrane Fuel Cell (HEMFC) is emerging as a promising technology due to its property of being able to operate in an alkaline environment where non-PGM can be used. The practical use of HEMFC has potential significance in that it can contribute to reducing fuel cell stack cost by excluding the use of PGM and improving electrochemical performance by avoiding harsh acidic operating conditions.
In this study, it was demonstrated that high electrochemical performance can be achieved by applying the silver (Ag) catalyst synthesized by atomic layer deposition (ALD) to the HEMFC electrode [1]. We successfully deposited Ag catalyst in the form of nanoparticulate on porous carbon nanotube-based electrode layers using plasma-enhanced ALD. HEMFC comprising an ALD Ag-coated cathode achieved a high-power density of 2,154 mW/mgAg. It was verified through EIS analysis that cathodic polarization loss, which accounts for a large part of energy loss, is greatly improved in the HEMFC cathode using the optimal ALD Ag condition. This study is meaningful in that it confirmed the potential application of ALD in the design and manufacture of high-performance electrocatalysts for HEMFC in the future.
[1] Park, J.S., Seo, B.G., Koo, J., Lim, J.H., Lee, Y.S., Han, G.D., Prinz, F.B. and Shim, J.H., 2023. High-Performance Hydroxide Exchange Membrane Fuel Cell Comprising an Atomic Layer-Deposited Silver Cathode. Nano Letters, 23(17), 2023.
Design of PNP SiGe HBTs Towards 200 GHz fmax
Authors: Raghunathan Uppili , Shank Steven , McTaggart Sarah , Lydon-Nuhfer Megan , Luce Cameron , Hazbun Ramsey , Bosley Stephen , Vallett Aaron , Dillon Daisy , Sirohi Saurabh , Johnson Jeffrey B. , Derrickson Alexander , Jain Vibhor , Pekarik John Jack 
Published: December 2024

In the three decades of production, SiGe HBTs have numerous applications including RF and high-speed mixed-signal and analog. While successive generations of BiCMOS technologies in the past have employed process and layout scaling, the advanced high performance platforms (with several 100 GHz fmax) have mostly been restricted to SiGe NPN optimization, and the Si PNP is often only offered as a dependent device with significantly slower speed. There truly exists a gap in literature with the PNP device variants showcasing good fT and fmax above 150 GHz in a BiCMOS platform. It is worth noting that much of the serviceable applications above can be designed with NPN-only topologies. However, having the complementary PNP enables several advantages, including power savings, improved gain, reduced design complexity, and improved reliability.
There are several challenges for making high performance PNP devices including reduced minority mobility in the intrinsic base from the conducting holes, elevated base current from minority electron injection into the emitter, and heterojunction barrier effect directly on the carrier pathway in the collector-base junction. The figure below shows the measured fT/fmax characteristics for a SiGe PNP with Ae = 0.12x2.5 um2 built using a 130nm technology framework optimized for a PNP-only process. The present work expands on the measured results (AC + DC) and the challenges faced in optimizing PNP performance for 200 GHz fmax and beyond.

Figure 1
200 mm Wafer Level Characterization at 2 K of Si/SiGe Field-Effect Transistors
Authors: Komericki Nikola David , Muster Pascal , Reichmann Felix , Huckemann Till , Kaufmann Daniel , Yamamoto Yuji , Lisker Marco , Langheinrich Wolfram , Schreiber Lars R , Bluhm Hendrik , Quay Ruediger 
Published: December 2024

The development of a fault tolerant quantum computer necessitates an expansion to millions of physical qubits while maintaining high coherence and minimal error rates. Gated Si/SiGe spin qubits are one of the main contenders to achieve this goal, thanks to the compatibility with existing industrial CMOS processes, which heralds vast capacities and elevated quality benchmarks. Elegant architectural approaches towards scalability of qubits include the electron shuttling over long distances, which promise a reduction of peripherals and opens up space for control electronics.
The concept of Si/SiGe spin qubits and shuttling structures is based on the z-direction confinement of 2D electron gas in a Si quantum well, which is additionally tailored in the x-y-plane by potentials that arise from multiple gate layers. To trace the viability of these complex devices, it is advisable to first check basic functionality of the gate layers with teststructures, like field effect transistors (FETs). It is particularly relevant to characterize at temperatures comparable to the target operating temperature of Gated Si/SiGe spin qubits.
Recently, Fraunhofer IAF has installed a 300 mm wafer prober that can perform device characterization at temperatures as low as 2K. In the related research project, the wafer prober is implemented in a fully industry compatible feedbackloop within heterostructure growth at IHP and device fabrication at Infineon. We present in this paper the viability of this approach by comparing and discussing the current-voltage characteristics and the resulting threshold voltage measured at room temperature and at 2K of 213 FETs on a 200mm wafer. We show the significance of characterizing devices at cryogenic temperatures rather than at room temperature. At 2K, observations were made regarding the presence or absence of off-current, resulting in the clustering of I-V curves and variations in threshold voltage. The origin of these phenomena is scrutinized, examining whether they stem from the cryogenic wafer prober system or are inherent to the FET design. Possible causes are discussed and explored.
Funded by the German Federal Ministry of Education and Research (BMBF) within the QUASAR ”Semiconductor quantum processor with shuttling-based scalable architecture” project.