bluuebunny/crossref_metadata_2025_split huggingface dataset:
Membrane-Based Zero Gap CO2 Electrolyzer with Au Cathode Prepared By Electrodeposition
Authors: Kim Junhyeong , Guo Wenwu , Han Gyeong Ho , Oh Jeong Hyun , Yeon Kyurim , Ahn Sang Hyun 
Published: December 2020

Electrochemical CO2 conversion has been recognized as a promising technology that can overcome the global warming. Also, the production of useful fuels (e.g. CO, HCOOH, CH4, CH3OH and C2H4) is capable via electrochemical reduction of CO2. It was demonstrated that at least 200 mA cm–2 of partial current density should be required for commercial operation. However, in conventional aqueous system, the CO2 electroreduction was limited to 35 mA cm–2 of current density due to low CO2 solubility into the electrolyte. Furthermore, the diffusion length of CO2 from bulk to catalyst is much longer in H-type cell system causing prevent easy supply of CO2. To overcome these problems, a single cell based on a membrane electrode assembly (MEA) with zero gap between the electrodes was introduced to facilitate CO2 mass transfer to the catalyst surface.
In this study, we investigate the MEA-based CO2 electrolyzer with anion exchange membrane. The electrodeposited Au on gas diffusion electrode (GDL), which exhibits the high CO production selectivity in CO2 electroreduction, was directly used as a cathode of CO2 electrolyzer. The humidified CO2 gas is supplied into cathode to promote the CO2 mass transfer to the catalysts-membrane interfaces. Furthermore, the content of polytetrafluoroethylene on GDL was controlled in order to prevent the product crossover between compartments that is feasible to exhibit stable performance. Compared to conventional H-type cell system, the 2-order magnitude improvement of partial current density was shown in MEA-based zero gap CO2 electrolyzer owing to low ohmic resistance and facile CO2 mass transfer.
Aggregate-Free Deposition of Highly Organized Nanocomposite Silica Thin Films on Conductive Substrates By Electrochemically Induced Templated Sol-Gel Synthesis
Authors: Vanheusden Genis , Philipsen Harold , Vereecken Philippe M. 
Published: December 2020

The synthesis of ordered nanocomposite or nanoporous silica thin films by template-assisted sol-gel processes offers interesting applications in various fields including catalysis, sensors, membranes and energy. The electrochemically assisted self-assembly method allows the growth of highly ordered vertically aligned nanoporous silica thin films on conductive substrates. This orientation, optimized for high mass-transport capabilities, is difficult to obtain by classical approaches. The method involves submerging the conductive substrate in a pre-hydrolyzed precursor liquid followed by the application of a cathodic potential, thereby causing the electrogeneration of hydroxide ions. The pH increase in the diffusion layer near the electrode surface catalyzes the sol-gel formation and the result is a silica thin film that grows on the conductive substrate. The addition of cetyltrimethylammonium bromide (CTAB) micelle templates leads to the formation of a highly ordered nanostructure.
A fundamental limitation of the method as reported in the literature is that the maximum layer thickness which can be obtained is rather limited due to the formation of aggregate by-products. In our contribution we show that diffusion layer thickness control is essential to obtain aggregate-free layers. Silica formation is catalyzed by OH- formed in the electrode’s diffusion layer, which quickly grows up to hundreds of microns under stationary conditions, thereby leading to composite thin films as well as precipitation of aggregates. By using a rotating disc electrode, the hydrodynamic layer is controlled, enabling aggregate-free film growth over a wide thickness range. Additionally, thin film coatings on high aspect ratio micropillar structures were demonstrated. Parameters such as precursor age, deposition temperature and deposition current were systematically investigated and the deposits were characterized using SEM, ellipsometry, TEM, FT-IR and an electrochemical redox probe. Using these techniques, we demonstrated the controlled growth of aggregate-free, uniform and nanostructured thin films with high mass-transport capabilities and thicknesses of 20 nm up to 15 µm, thereby significantly expanding the range of 50-150 nm as reported in literature. These results are explained using a single hydrodynamic layer model.

Figure 1
High-Speed Electrodeposition of Textured Monolithic Lithiated Transition Metal Oxide Cathodes for High Energy and Fast Charging Li-Ion Batteries.
Authors: Cook John B. 
Published: December 2020

Xerion Advanced Battery Corp, founded in 2010, is in the process of commercializing two battery technologies: a) a nanoscale metal foam, produced through electrodeposition, that enables high performance alloy-type active material based electrodes, and b) a single-step electroplating process to manufacture lithiated transition metal oxide (LTMO) cathodes.
Xerion’s process benefits from the combined synthesis and electrode formation in just one step – revolutionizing the current commercial slurry-electrode manufacturing process (>20 steps). Certain LTMO’s can be grown as a monolithic structure up to 500 m thick (~ 5 times thicker than state of the art), while simultaneously controlling the crystalline orientation, porosity, surface area and morphology. Ultra-thick textured electrodes significantly decrease the volume, thickness and weight of the resulting battery without compromising run time or power-density. In addition, the deposition process can be applied onto arbitrary shapes giving way to storage solutions that could be integrated as structural and load bearing components leading to low form-factors, ultra-light weight solutions, and new designs. Safety is also improved because conductive agents are not added to the electrode eliminating secondary conductive pathways, which can prevent hard shorts that lead to disastrous thermal run-away events.
The transformative electroplating process can utilize low purity feedstocks instead of highly purified lithium hydroxides and lithium carbonates to produce highly pure Li-ion battery cathodes at a fraction of the cost. This feedstock flexibility arises from selective solubility and differences in redox potential of the desired material and the undesired impurity phases. While commercial active material manufacturing requires feedstock purity >99.5%, purities as low as 50% have been demonstrated with Xerion’s molten salt process. As a result, cost modeling has shown that cost to manufacture cells using this process is reduced by up to 50% even when using an expensive cathode chemistry like LiCoO2. The single-step manufacturing method that produces safe batteries with high energy, fast charging, and high-power characteristics, while simultaneously reducing the cost, is possible through the innovative technology being brought to the market by Xerion Advanced Battery Corporation.
A Multimodal Electronic Nose Based on High-Density Flexible Sensor Array of Carbon Nanotubes and Photoactive Macromolecules Hybrid Nanostructures
Authors: Tran Thien-Toan , Park Hyusim , To Dung , Gangadhara Karthik , Brady Jacob , Hart Joseph , Jung Sungyong , Myung Nosang Vincent 
Published: December 2020

We report a multimodal electronic nose system based on photoactive carbonaceous hybrid nanomaterials for the detection and quantification of gaseous odors. The e-nose system comprises a high-density flexible sensor array, colorimetric and electrical measurement electronics, data acquisition software, and data analysis algorithms. The e-nose system combines the unique advantages of electrical, chemical, and physical properties of single-walled carbon nanotubes (SWNTs) with optical and chemical properties of various classes of organic macrocyclic compounds, such as pyrenes, porphyrins, and phthalocyanines, for multimodal gas sensing. Photoactive macromolecules such as metalloporphyrins and metallophthalocyanines have been previously developed into colorimetric sensors to various gas analytes. Their intrinsically low electrical conductivity prevents direct application of porphyrins and phthalocyanines in chemiresistive sensors. However, when used as a secondary sensing material via functionalization onto SWNTs, which intrinsically lacks chemical selectivity, these macromolecules confer their chemical selectivity and optical properties to the intrinsically semiconducting SWNT channel. This hybrid nanostructure allows both chemiresistive sensing and colorimetric sensing modalities. Another beneficial property of this hybrid nanostructure is the optoelectronic tunability of the nanomaterial to allow for direct modulation of chemical and electrical behaviors leading to tunable gas sensing capability.
Using the high-density array containing 118 individually addressable sensors, over 60 different secondary sensing materials (functionalized onto SWNTs) were investigated, which include chemical derivatives of pyrenes, porphyrins, and phthalocyanines, which have a large variety of side-groups, and metal centers. Additionally, by integrating a large variety of secondary sensing materials into each sensing element of the 118-sensor array, we take advantage of the different chemical and electrical characteristics of each macromolecules which allow for different affinities to specific VOC species to enhance overall selectivity of the e-nose system. The functionality of the multimodal e-nose system was demonstrated to distinguish and quantify various volatile organic compounds (VOCs).
Role of Ni, Mn and Co in Layered Rock Salt Cathode Materials for Li-Ion Battery: A DFT Study
Authors: Fujiwara Yoshiya , Morita Yoshiyuki , Ogasa Hiroshi , Fujisaki Fumika , Kushima Akihiro 
Published: December 2020

Li-ion battery (LIB) has high energy/power density and long cycle life among other battery systems. LiCoO2(LOC) is a commonly used LIB cathode material which has a layered rock salt structure. To meet environmental needs, especially for the reduction of CO2, electrification of the automotive applications requires high volume of batteries. Here, Co which is a key element of LIB has potential supply risks due to its geological availability and value chains. Although, low-Co and high Ni cathode materials such as LiNiMnCoO2 (NMC) or LiNiCoAlO2 (NCA) have been developed by Edisonian approach, the role of Co in the cathode materials with layered rock salt structure is still not clear. To understand the role of Co, we conducted a comprehensive study with modeling and simulation backed up by the synchrotron X-ray experiment. A series of density functional theory (DFT) calculation was performed using the Vienna Ab initiation Simulation Package (VASP)[1,2] within the projector augmented-wave method and generalized-gradient approximation (GGA). All calculations were performed employing PBE-GGA+U. Change in the charge density distributions and thestructure parameters at different states of charge (SOCs) were calculated for mono-transition-metal oxidessuch as LCO, LiNiO2 (LNO) and LiMnO2 (LMO) as well as ternary-transition material NMC with different composition ratio, ie NMC111, NMC622, NMC811. Figure 1 shows Bader charge analysis[3] result for each elements in LCO, LNO and LMO as a function of the SOC. Detailed analysis with experimental results of XAFS and XRD, and will be discussed in the meeting.
[1] P. E. Blöch, Phys. Rev. B 50, 17953 (1994).
[2] G. Kresse et al., Phys. Rev. B 59, 1758 (1999).
[3] G. Henkelman, A. Arnaldsson, and H. Jónsson, Comput. Mater. Sci. 36, 354-360 (2006)

Figure 1
Hydrothermal Synthesis and the Cathode Properties of Na3MPO4CO3 (M = Fe, Mn, Ni, Co) with Highly Concentrated Aqueous Electrolyte
Authors: Okada Masaki , Chiba Kazuyuki , Matsunaga Osamu , Kobayashi Wataru , Takahara Toshiya , Takahashi Kennichi , Sakamoto Ryo , Okada Shigeto 
Published: December 2020

Na-ion batteries (NiBs) have drawn much interest as low cost and low environmental impact power source for large-scale grid storage system, because of the abundant resources of sodium. For the past decades, various iron-based polyanionic compounds have been extensively studied as cathode materials for NiBs. Among the candidate of cathode active materials for NiBs, practical use of iron phosphate such as NaFePO4, Na2FePO4F, and Na3Fe3(PO4)4 [1] or carbonophosphate such as Na3FePO4CO3 [2] is expected from the viewpoint of cost and safety.
Recently, our group confirmed that 17m NaClO4 aqueous electrolyte showed high operating voltage up to 2.78V in both Na and Li systems [3]. By using 17 m NaClO4 aqueous electrolyte, it was found that Na3FePO4CO3 prepared by mechanical ball milling provided an initial discharge capacity of 161 mAh g-1 between -1.2 and 1.3 V with a reference electrode of Ag/AgCl at 2 mA cm-2 [4].
In order to make full use of the resource and cost advantages of carbonophosphate, the raw materials used in the synthesis and the synthesis method are also important. In this presentation, we report the direct synthesis of Na3MPO4CO3 (M = Fe, Mn, Co, Ni) by the hydrothermal method and the cathode properties.
Figure 1 shows charge-discharge profiles of Na3FePO4CO3 obtained by hydrothermal synthesis at 180 ° C for 16 hours using iron sulfate (II) (FeSO4·7H2O), trisodium phosphate (Na3PO4·12H2O), and sodium carbonate (Na2CO3) as raw materials. This hydrothermal synthesis Na3FePO4CO3 delivered initial discharge capacity of 112 mAh g-1.
In the presentation, we will be reported the details of cathode properties of the hydrothermal synthesized Na3MPO4CO3 (M = Fe, Mn, Co, Ni).
References
[1] S. Okada, H. Arai, J. Yamaki, DENKIKAGAKU, 65 (1997) 802.
[2] H. Chen, G. Hautier, G. Ceder, J. Am. Chem. Soc., 134 (2012) 19619.
[3] K. Nakamoto, R. Sakamoto, M. Ito, A. Kitajou, S. Okada, Electrochemistry, 85 (2016) 179.
[4] B. Xie, R. Sakamoto, A. Kitajou, K. Nakamoto, L. Zhao, S. Okada, Y. Fujita, N. Oka, T. Nishida, W. Kobayashi, M. Okada, T. Takahara, Sci. Rep., 10 (2020) 3278.

Figure 1
Estimation of Kinetic Parameters of Additives By Semi-Analytical Solution
Authors: De Shuvodeep , Huang Qiang 
Published: December 2020

The electrodeposition of Cu and other metals is an essential step in the interconnect fabrication, 3-D integration, and various packaging technologies. Such electrodeposition processes are enabled by a group of organic additives. Furthermore, strong agitation is often used to expedite the electrodeposition rate when the processing time becomes critical for large features, which however introduces non-uniform mass transport within a single feature and between different features. A numerical description of how organic additives behave in conjunction with external flow at various feature geometry and dimensions is a challenging task, but much needed for chemistry and process development. Among the various requirements, the additive behavior or their electrochemical impacts on Cu deposition needs to be precisely described.
This talk reports an effort to obtain the numerical parameters that describe the additive behaviors during Cu deposition on rotating disc electrodes (RDE). A one-dimensional semi-analytical model is developed for Cu electrodeposition from a two-component additive system. The steady-state mass transport differential equations of each chemical species, including diffusion and convection, are solved analytically at different potentials, while the boundary conditions at the RDE surface are coupled with each other through the surface coverages of adsorbed species. The steady state of such surface coverage results from a dynamic equilibrium between three co-existing processes, adsorption, desorption and incorporation (consumption), namely,

Adsorption Rate – Desorption Rate – Consumption Rate = 0

A set of solutions, including the concentration profile of each species in electrolyte as well as the surface coverage of each adsorbate, can be obtained at a fixed potential. The equations are first solved considering only the suppressor for a range of over-potential. It was found that, for a specific range of voltages and kinetic parameters, multiple non-trivial solutions of surface coverage exist. In other words, multiple steady states exist at a same applied potential. As shown in Figure 1, this translates to a S-shaped negative differential resistance (NDR) feature in cyclic voltammogram (CV), consistent with experimental observation reported in literature. The numerically calculated NDR region was found sensitive to the additive concentration and therefore extremely useful in determining the electrochemical parameters using multiple experimental datasets with different concentrations. The swarm optimization algorithm used for parameter fitting and the correlation between multiple numerical solutions with the NDR region will be discussed in details in the talk.

Figure 1
A Study on Void-Free Filling of a High-Aspect-Ratio Though-Silicon Via
Authors: Jin SangHoon , Lee Woon-Young , Lee Dong-Ryul , Jo Yugeun , Lee Min-Hyung 
Published: December 2020

The void-free filling of high-aspect-ratio through silicon via (TSV) is one of the technical challenges for 3D integration. We suggest the seed step-coverage enhancement process (SSEP) for void-free filling of a high-aspect-ratio through-silicon via (TSV) because the Cu seed layer deposited usually by physical vapor deposition (PVD) shows the poor step coverage inside the TSV. The SSEP was performed by means of electroplating using an alkaline pyrophosphate solution after the deposition of the Cu seed layer. After the SSEP, in order to fill the TSV without void using a Cu electroplating, we suggest the optimization of the functional groups of levelers in the Cu electroplating solution. In this research, step-coverage enhancement was successfully achieved through optimization of the molar ratio of pyrophosphate ions to Cu ions in the plating solution and the current density. And then, we investigated the TSV filling performance dependent on the functional groups of levelers such as amines, imines, pyridines and pyrrolidones. As the result, it was determined that TSV filling performance was strongly affected by functional group of leveler. Only amines can succeed to fill a TSV without void under high speed electroplating of 1.3ASD. This result proves that the leveler can inhibit the faster electroplating at the upper edge of TSV effectively even at the high current density.

Reference

[1] H. Ling, H. Cao, Y Guo, H. Yu, M. Li and D. Mao, International Conference on Electronic Packaging Technology & High Density Packaging (2009) 860-862.
[2] K. Zou, H. Ling, Q. Li, H. Cao, X. Yu, M. Li and D. Mao, International Conference on Electronic Packaging Technology & High Density Packaging (2009) 103-106.
[3] L. Ma, H. Ling, M. Li, J. Sun, X. Yu and Y. Li, 14th International Conference on Electronic Packaging Technology (2013) 356-359
[4] R. Beica, C. Sharbono and Tom Ritzdorf, Electronic Components and Technology Conference (2008) 577-583
Electroless Deposition of Pure Cobalt Film for Realizing Low Resistivity LSI Interconnection
Authors: Morita Kosei , Saida Ryota , Matsudaira Taro , Shimizu Tomohiro , Ito Takeshi , Shingubara Shoso 
Published: December 2020

With a scaling trend of LSI interconnection, effective resistivity of Cu/barrier metal interconnect is expected to increase due to increasing electron scattering due to ultrafine dimension smaller than electron mean free path. Therefore, the trend is to substitute Co metal liner for Cu when the line width of LSI interconnect is 10 nm or less. While Chemical Vapor Deposition (CVD) or electrodeposition are discussed as formation method of Co mainly, we introduced electroless deposition (ELD) method. In electroless deposition of Co using Dimethylamine Borane (DMAB), B was incorporated in Co film, and the electric resistivity of the film after heat treatment (400℃ in vacuum, 30 minutes) was 68 µΩ∙cm. In this report, we introduced hydrazine monohydrate as a reducing agent for the purpose of forming ELD pure Co film.
ELD Co bath contains cobalt chloride hexahydrate (CoCl2∙6H2O) as metal ion source and hydrazine monohydrate (N2H4∙H2O) as a reducing agent. In addition, some complexing agents were added to prevent Co hydroxide precipitation. Plating bath pH was adjusted to about 12.3 and the CVD-Co film (thickness: 20 nm) on SiO2 and Si was used as substrate for Co deposition. Obtained Co plated film were observed and analyzed by Scanning Electron Microscope (SEM), X-ray Photoelectron Spectroscopy (XPS) and X-Ray Diffraction (XRD). Furthermore, Co plating film was heat-treated at 400℃ in vacuum, and the electrical resistivity of Co film before and after the heat-treatment was measured by four-terminal method.
The deposition rate of ELD cobalt bath was about 19 nm/min, and this cobalt film consisted of columnar crystals (Figure 1). If the film surface is rough, it may cause void formation during electroless Co plating in fine via. Regarding the properties of Co film, impurities derived from the reducing agent were not detected from XPS spectral analysis. Co film with few impurities leads to low resistivity because the probability of electron impurity scattering decrease. However, the resistivity of obtained and heat-treated Co film is 53 µΩ∙cm. It is necessary to form the smooth Co film to reduce the electrical resistivity.

Figure 1
Pulsed Current Vs. Organic Additives on Electrodeposition from Zincate Bath
Authors: Rauch Jeanne-Marie , Gigandet Marie-Pierre , Rolet Jason , Hihn Jean-Yves 
Published: December 2020

Among the various zinc electroplating baths, alkaline zincate solution has gained a wider range of applications thanks to its simple bath composition, good dispersion and efficient coverage ability. Nevertheless, alkaline zincate solution cannot be used as such and it is necessary to introduce additives to control the process performances [1]. Otherwise, efficiency is extremely low, and the properties of the coatings are disappointing. Additives can modify the crystal growth and therefore the structural and mechanical properties, the corrosion resistance, and the appearance of coatings [2]. In the absence of additives, the main problem is low efficiency, resulting from the competition between dihydrogen production and the reduction of the metallic species present in the bath.
Therefore, pulsed currents constitute an attractive way to eliminate the need for organic additives by significantly improving the Faradic yield. In this study, the influence of various pulsed current sequences versus the addition of organic additives is observed in the characteristics of the coatings as well as in the process execution. A key point in the determination of the pulse sequence is the study of the transient curves with a zincate bath. This allows for the identification of the most influential parameters on dihydrogen production, with direct consequences on the process mechanisms.
By knowing the τD i.e. diffusion time preceding hydrogen reduction, it is possible to design pulse sequences with limited gas production. This is confirmed by mass spectrometry measurements which quantify the total dihydrogen production for each pulse sequence. Fig 1.
The coating’s characterization consists in SEM analysis topographic pictures and preferential orientations and grain sizes determined through XRD. Results confirm the interest of pulsed currents versus organic additives for zincate baths.
[1] J. L. Ortiz-Aparicio, Y. Meas, G. Trejo, R. Ortega, T. W. Chapman, et E. Chainet, « Effects of organic additives on zinc electrodeposition from alkaline electrolytes », J Appl Electrochem, vol. 43, no 3, p. 289-300, mars 2013, doi: 10.1007/s10800-012-0518-x.
[2] L. Yuan, Z. Ding, S. Liu, W. Shu, et Y. He, « Effects of additives on zinc electrodeposition from alkaline zincate solution », Transactions of Nonferrous Metals Society of China, vol. 27, no 7, p. 1656-1664, juill. 2017, doi: 10.1016/S1003-6326(17)60188-2.

Figure 1