bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrogen in Electrolessly Deposited Ni/Au and Ni/Pd/Au Films
Authors: Yae Shinji , Oda Yukinori , Sagara Yusaku , Fukumuro Naoki 
Published: December 2020

For the surface finishing of copper layer on printed circuit boards, autocatalytic electroless deposition of nickel-phosphorus alloy and immersion deposition of gold (ENIG, Ni-P/Au) or autocatalytic electroless deposition of Ni-P, palladium and immersion deposition of Au (ENEPIG, Ni-P/Pd/Au) are widely used. The Ni-P/Pd/Au surface finish is suitable not only for lead-free soldering but also for wire bonding [1]. For soldering, it was reported that hydrogen plasma improved bonding behavior and realized a flux-free process [2]. Electrochemically deposited metal films include hydrogen atoms. The hydrogen adsorbed in metal films causes various phenomena such as atomic diffusion, alloying, crystal growth, void formation. We have been investigating the atomistic state and behavior of hydrogen in electrodeposited metals by thermal desorption spectroscopy [3, 4]. In this study we measured changes in hydrogen amounts in the Ni-P/Au and Ni-P/Pd/Au surface finishes [5]. We used two different electroless Pd baths using formic acid (Ni-P/Pd/Au) and sodium phosphinate (Ni-P/Pd-P/Au) as reducing agents. The Ni-P films contained large amounts of diffusible hydrogen that desorbs at room temperature. During autocatalytic electroless deposition of Pd and Pd-P on Ni-P films, the greater part of the hydrogen in the Ni-P films desorbed. Although no hydrogen evolution accompanied immersion Au deposition, the hydrogen amounts in Ni-P/Au, Ni-P/Pd/Au, and Ni-P/Pd-P/Au films were much greater than in films without a Au layer. Moreover, at room temperature, they remained almost unchanged for one month after deposition, indicating that the thin Au layer (< 0.1 μm) prevents hydrogen desorption from the metal films. The high hydrogen concentration in Ni-P/Au films improved solder wettability.
[1] Y. Oda, M. Kiso, S. Kurosaka, A. Okada, K. Kitajima, and S. Hashimoto, Proc. Internal. Microelectronic and Packaging Soc., IMAPS (2008).
[2] T. Hagihara, T. Takeuchi, and Y. Ohno, Proc. 10th Electronics Packaging Technology Conf. (IEEE), 595 (2008).
[3] N. Fukumuro, S. Kojima, M. Fujino, Y. Mizuta, T. Maruo, S. Yae, and Y. Fukai, J. Alloy. Comp., 645, S404 (2015).
[4] N. Fukumuro, K. Tohda, and S. Yae, this symposium.
[5] Y. Oda, Y. Sagara, N. Fukumuro, and S. Yae, J. Surf. Finish. Soc. Jpn., 70, 163 (2019).
Hydrogen Generation from an Alkaline NaBH4 Solution Using Different Cobalt Catalysts
Authors: Sukackiene Zita , Balciunaite Aldona , Tamašauskaitė-Tamašiūnaitė Loreta , Norkus Eugenijus 
Published: December 2020

The effective Co, CoB and CoBM, where M = Mo, Zn, and Fe, catalysts have been deposited on the Cu surface by a simple electroless metal deposition method using morpholine borane as a reducing agent and used as catalysts for hydrogen generation from an alkaline NaBH4 solution. The catalytic activity of different cobalt alloys catalysts towards the hydrolysis of NaBH4 has been investigated by measuring the amount of generated hydrogen from an alkaline solution contained 5 wt. % NaBH4 and 0.4 wt. % NaOH. The rate of H2 generation has been measured at solution temperatures in the range from 298 to 318 K in order to determine the activation energy.
It has been determined that the synthesized Co/Cu, CoB/Cu and CoBM (M=Mo,Zn,Fe)/Cu catalysts demonstrate the catalytic activity for the hydrolysis reaction of NaBH4. The lowest obtained activation energy of the hydrolysis reaction of NaBH4 has been 27 kJ mol-1 for the CoBMo/Cu catalyst. The hydrogen generation rate has been achieved 15.30 ml min-1 using the CoBMo/Cu catalyst at a temperature of 313 K and it increases ~3.5 times with the increase of temperature to 343 K. Moreover, the CoBMo/Cu catalyst shows a highest catalytic activity for hydrogen generation from the alkaline NaBH4 solution as compared with that for other Co/Cu, CoB/Cu, CoBZn/Cu, and CoBFe/Cu catalysts.
(Invited) Electroforming in Space and Ground Telescopes
Authors: Valsecchi Giuseppe , Banham Robert 
Published: December 2020

In the last 25 years, electroforming process has been extensively optimised to produce grazing incidence optics for the X-ray space telescopes, enabling the renown observatories Beppo-SAX for the Italian Space Agency, SWIFT for NASA, XMM Newton for ESA, eROSITA for MPE.
These optics are made of thin Nickel mirrors that are grown by electroforming process in an electrolytic bath on a Gold coated mandrel.
Mandrels are manufactured in Aluminium alloy with NiP coating, which allows, after polishing to reach very smooth roughness in the order of 0.3 nm.
After separation of the mirror from the mandrel, Gold layer becomes the X-Ray optical reflecting coating, preserving the low roughness of the mandrel.
The Nickel Mirror shells are nested tightly in high-performance optical structures, the X ray telescope.
The electroforming cycle ranged between 40 and 100 hours, depending on the thickness of the mirrors, typically between 0.2 and 0.6 mm for the innermost and outermost shells, respectively. The average electroforming time is 65 hours per mirror, with 1 hour for assembly and preparation of the mandrel and 1 hour for separation after electroforming.
Electroforming has also been adopted for production of large reflector panels for sub-millimetre radio telescope applications. These are laminated panels made of electroformed Nickel skins bonded to an Aluminium honeycomb core over a precise mould, resulting in typical shape accuracy of 8 µm at only 10 kg/m² mass density.
Between 2006 and 2016, 3000 mirror panels for 25 antennas of the ALMA radio-telescope array of ESO and 1600 mirror panels for the 50-m diameter Large Millimetre Telescope (LMT) “Alfonso Serrano” of INAOE were designed, produced and tested.
Electroforming replica consists of the replication of mirror substrates from high precision mandrels by means of the electroforming process.
The mandrel is machined and polished to the shape accuracy and surface roughness requirements of the final mirror.
In the electroforming process, the mandrel is Gold-coated by e-beam evaporation and then immersed in the electrolytic bath. Nickel ions, deposit onto the Gold-coated mandrel creating a low-stress Nickel mirror.
Upon reaching the desired thickness, the mandrel is removed from the bath and the mirror is separated from the mandrel. In this process, the Gold layer is bonded to the mirror, creating an integrated reflective layer with the same roughness as the mandrel. The mandrel is then qualified for the next electroforming cycle, where another mirror is replicated from the same mandrel, and so on for the following cycles.
Process cycles, key inspection points, verification and testing as part of the production cycles will be described and presented.
Panoramic view of ALMA radio-telescopes. Photo courtesy of ESO.

Figure 1
Magnetic Fluids Assisted Electro-Leaching of Metals
Authors: Accogli Alessandra , Pesce Ruggiero , Magagnin Luca 
Published: December 2020

In current research, micro and nanoparticulate electrode materials have taken their place because they offer a large internal surface area with respect to the macroscopic dimensions of such electrodes [1]. The nano-impact method is a powerful tool that enables the characterization of individual particulate nano-objects in solution and study of their reactivity [2]. A three electrodes setup system working as a standard electrochemical cell is typically used. Magnetite (Fe3O4) nanoparticles with the strongest saturation magnetization of all naturally occurring iron oxides, combined with properties such as low toxicity, good biocompatibility, high stability, and low production costs, have attracted a lot of interest [3]. There is also substantial interest in their use as magnetic fluids, in data storage, in catalysis, and as electrode materials.
In this work, magnetite micro and nanoparticles have been synthetized by chemical precipitation method in presence of surfactants or functional organic polymer. The use of surfactants to stabilize these synthesized nanoparticles is crucial, as Fe3O4 nanoparticles have high surface energies and tend to aggregate. Magnetic fluids constituted by dispersed functionalized magnetite particles are used as particulate electrode in different fluids and characterized into a three electrodes cell in order to evaluate their electrochemical behavior. A deeper understanding of the particulate electrode has been performed in situ on supported particles through electrochemical AFM/STM measurements, highlighting the behavior of the single aggregate. Together with the charge transfer characterization as a function of particles size and concentration, functionalization and fluid composition, practical applications of the particulate electrodes will be presented. Specifically, the use of particulate electrodes in the electrochemical metal recovery, showing the ions adsorption properties of magnetite particles as a function of surface functionalization and their electrochemical reduction at the magnetic fluid/current collector interphase will be discussed for specific systems, e.g. copper and lithium.
1.V. Noack, H. Weller, A. Eychmu1ller, J. Phys. Chem. B, 106 (2002) 8514-8523
2. S.V Sokolov et al., Phys.Chem.Chem.Phys., 19 (2017) 28
3. K. Murugappan, ChemElectroChem, 1 (2014) 1211 – 1218
Impact of Annealing Time on Lithium Local Environment of LiMn0.5Ni0.5O2: DFT-Supported 6 Li Solid-State NMR Study
Authors: Shin Woochul , Vu Anh , Garcia Juan , Ji Xiulei , Iddir Hakim , Dogan Fulya 
Published: December 2020

To quench the thirst of ever-increasing demand for high energy and low-Co lithium-ion batteries (LIB), LiMn0.5Ni0.5O2 has received considerable attention as a promising alternative cathode. However, it has been plagued by the structural failure driven by the irreversible phase change upon subsequent cycling and the structural degradation caused by the unavoidable Li/Ni exchange.[i] This brings the importance of understanding the relation with lithium local environments and domains on overall electrochemical properties of materials.
In this study, we have focused on two different samples, prepared by different annealing times (150 vs. 15 hours) to elucidate the change of local lithium surroundings and its sensitivity to the annealing time. We use a combination of 6Li solid-state magic angle spinning (MAS) nuclear magnetic resonance (NMR)[ii] and density functional theory (DFT)[iii] techniques to illuminate the impact of annealing time to the local lithium environment of LiMn0.5Ni0.5O2. Examination of NMR spectra reveals peak shift and intensity change, which is scrutinized by the assistance of DFT that is capable of deconvoluting the NMR spectra and obtain the corresponding local lithium environment. We compare the NMR spectra of the previously reported transition metal arrangements such as a zigzag, row, and honeycomb structures and describe the influence of Li/Ni exchange on the shape of the spectra. Overall, we combine the various computed-NMR spectra that show in close proximity to the experimental spectra, which provides new insights to understand the correlation between annealing time and local lithium environment for a promising LIB cathode design.

[i] Ceder, G. et al., Phase Transitions in the LiNi0.5Mn0.5O2 System, Chem. Mater. 2007, 19, 7, 1790–1800

[ii] Grey, C. P. et al., NMR Studies of Cathode Materials for Lithium-Ion Rechargeable Batteries, Chem. Rev. 2004, 104, 4493−4512
[iii] Casas-Cabanas, M. et al., DFT-Assisted Solid-State NMR Characterization of Defects in Li2MnO3, Inorg. Chem. 2019, 58, 8347−8356
Local Electrochemical Impedance Spectroscopy: Towards an Improvement in the Low Frequency Domain
Authors: Pereira Gomes Maurilio , Costa Isolda , Pebere Nadine , Rossi Jesualdo Luis , Turmine Mireille , Vivier Vincent 
Published: December 2020

The ability to probe surface reactivity at the local scale has led to a new understanding of the electrochemical reactivity in relation to the surface microstructure. Among the various techniques developed in recent years, local electrochemical impedance spectroscopy (LEIS) takes advantage of using a transient approach to locally characterize a stationary electrochemical system without the need to add any redox mediator in solution. The principle of LEIS was pioneering by Isaacs et al. [1, 2]. The local current density, , is obtained from the local potential difference in solution, , measured with a probe which consisted in three reference microelectrodes positioned close to the interface of interest, as depicted in Fig. 1.
Whatever the mode of operation, the spatial resolution of the technique is governed by the following parameters [3, 4]:
- The diameter of each microelectrode used for sensing the local potential in solution;
- The distance between the two potential microprobes (the smaller the distance, the smaller the potential difference) [5];
- The distance between the dual probe and the substrate is an important parameter to be considered. Due to the potential distribution in the electrochemical cell, the difference in potential to be measured will be smaller if the probe is positioned far from the substrate. This may result in difficulties in measuring properly LEIS response in the low frequency domain, as regularly encounter, for instance, in coating degradation application.
In the present work, we reported a new experimental setup that allows the measurement of local electrochemical impedance response of an interface in a wide frequency range, including the low frequency domain which is discussed. Proofs of concept with model systems, as well as passive materials and coatings are presented.

Keywords:Local electrochemical impedance spectroscopy; low frequency measurements; electrochemical instrumentation; micro-electrochemistry.

References

[1] R.S. Lillard, P.J. Moran, H.S. Isaacs, A novel method for generating quantitative local electrochemical impedance spectroscopy, J. Electrochem. Soc., 139 (1992) 1007-1012.
[2] F. Zou, D. Thierry, H.S. Isaacs, A high-resolution probe for localized electrochemical impedance spectroscopy measurements, J. Electrochem. Soc., 144 (1997) 1957-1965.
[3] V.M.-W. Huang, S.-L. Wu, M.E. Orazem, N. Pebere, B. Tribollet, V. Vivier, Local electrochemical impedance spectroscopy: A review and some recent developments, Electrochim. Acta, 56 (2011) 8048-8057.
[4] O. Gharbi, K. Ngo, M. Turmine, V. Vivier, Local electrochemical impedance spectroscopy: A window into heterogeneous interfaces, Current Opinion in Electrochemistry, 20 (2020) 1-7.
[5] C.P.d. Abreu, C.M.d. Assis, P.H. Suegama, I. Costa, M. Keddam, H.G. de Melo, V. Vivier, Influence of probe size for local electrochemical impedance measurements, Electrochim. Acta, 233 (2017) 256-261.

Figure 1
X-Ray Microtomography Analysis of Li-Sulfur Batteries with a Block Copolymer Electrolyte
Authors: Devaux Didier , Villaluenga Irune , Jiang Xi , Chang Yu Hao , Parkinson Dilworth Y. , Balsara Nitash P. 
Published: December 2020

Li-ion batteries are the dominant solution for many applications, from small electronic devices up to hybrid and fully electric vehicles.[1] However, this technology is now mature and new chemistries are needed to reach high specific energy while ensuring safety. Despite a relatively low operating voltage, sulfur (S8) is an attractive cathode active material due to its high theoretical specific capacity; a factor of six higher than traditional LiCoO2 cathodes.[2] To realize high energy density systems, the S8 cathode must be paired with a Li metal anode. Many challenges remain to be addressed to effectively couple a Li metal with a S8 cathode such as the low S8 utilization, the strong volume change of active material upon cycling, the insulating nature of S8 and of the final product Li2S, the solubility of polysulfides in the electrolyte.[3] This issues lead to poor capacity retention, limited cycle life, and low Coulombic efficiency. To address the polysulfide dissolution problem one approach consists in confining S8 within mesoporous and nanoporous carbon.[4] However, conventional liquid electrolytes are not stable against Li metal. A solution is then to use a solid polymer electrolytes, such as polystyrene-b-poly(ethylene oxide) (SEO) block copolymer doped with LiTFSI salt, known to stabilize Li metal.[5]
The goal of this study is to understand the behavior of Li-S8 batteries comprising a SEO electrolyte. The cathode is a composite made of carbon, SEO electrolyte and sulfur-impregnated carbon nanospheres.[6] The cells were cycled and exhibited significant capacity fade. We thus used hard X-ray microtomography to determine the reason for this capacity fade. Figure 1 represents tomography images prior and after cycling. In addition to polysulfide dissolution, our observations indicate that the battery failure in our system is also due to strong changes at the Li/SEO interface.

References

[1] J. B. Goodenough, K.-S. Park, J. Am. Chem. Soc., 135 (2013) 1167 (2013).
[2] P. G. Bruce, S. A. Freunberger, L. J. Hardwick, J.-M. Tarascon, Nat. Mater., 11 (2012) 19.
[3] S. S. Zhang, J. Power Sources, 231, 153 (2013).
[4] X. Fan, W. Sun, F. Meng, A. Xing, J. Liu, Green Energy Environ., 3 (2018) 2.
[5] D. T. Hallinan, S. A. Mullin, G. M. Stone, and N. P. Balsara, J. Electrochem. Soc., 160, (2013) A464.
[6] D. Devaux, I. Villaluenga, X. Jiang, Y. H. Chang, D. Y. Parkinson, N. P. Balsara, J. Electrochem. Soc., 167 (2020) 060506

Figure 1
A Model-Based Insight into Electrolyte Behaviour in Aqueous Zinc-Ion Batteries
Authors: Borchers Niklas , Horstmann Birger 
Published: December 2020

Next-generation batteries strive for the optimal fit in performance, cost, and environmental safety. Within recent times, a whole playground of different material systems and working principles were investigated. Consumer alkaline batteries with a metallic zinc anode and manganese dioxide cathode achieve excellent energy densities of [1], yet their development stalled due to their limited rechargeability. Switching the aqueous electrolyte from alkaline KOH to, for example, mild electrolytes, however, showed a reversible charge/discharge mechanism at the cathode [2]. This achievement highly increased the research interest in zinc-ion batteries in the last decade, and many successful systems were proposed [3], [4].
Aqueous metal batteries face a series of challenges. The limited stability window of water, as well as unwanted precipitation reactions, deteriorate the battery performance and increase aging reactions. The electrolytes composition and the concentration-dependent complex formation governs its performance. Within Zinc-air batteries, we performed model-based optimization studies of pH adjusted electrolytes [5].
Yet, to our knowledge, there is no modelling work done for zinc-ion batteries. Within our contribution, we combine a description of complex formation with a dynamic cell model. The electrolyte speciation significantly influences the transport properties of the electrolyte as well as its stability. With our cell model, we predict the performance and rate-dependent behavior of commonly used materials. With this, we identify system-requirements and pitfalls in the ongoing optimization of aqueous zinc-ion batteries.
This work is supported by the Federal Ministry of Education and Research (BMBF) via the project ZIB.

Literature

[1] S. Clark, N. Borchers, Z. Jusys, R. J. Behm, and B. Horstmann, Aqueous Zinc Batteries. 2020.
[2] C. Xu, B. Li, H. Du, and F. Kang, “Energetic Zinc Ion Chemistry: The Rechargeable Zinc Ion Battery,” Angew. Chemie Int. Ed., vol. 51, no. 4, pp. 933–935, Jan. 2012, doi: 10.1002/anie.201106307.
[3] B. Tang, L. Shan, S. Liang, and J. Zhou, “Issues and Opportunities Facing Aqueous Zinc-ion Batteries,” Energy Environ. Sci., pp. 3288–3304, 2019, doi: 10.1039/c9ee02526j.
[4] J. Huang, Z. Guo, Y. Ma, D. Bin, Y. Wang, and Y. Xia, “Recent Progress of Rechargeable Batteries Using Mild Aqueous Electrolytes,” Small Methods, vol. 3, no. 1, p. 1800272, Jan. 2019, doi: 10.1002/smtd.201800272.
[5] S. Clark et al., “Designing Aqueous Organic Electrolytes for Zinc-Air Batteries: Method, Simulation, and Validation,” Adv. Energy Mater., vol. 10, no. 10, p. 1903470, Mar. 2020, doi: 10.1002/aenm.201903470.

Figure 1: Schematic of the interaction of the evaluation of electrolyte composition and the cell model. Illustration on the left adapted from [1]

Figure 1
(Invited) Theoretical Study on the Energy Storage Mechanism of Transition-Metal-Carbide MXene By Quantum-Classical Hybrid Simulation
Authors: Ando Yasunobu 
Published: December 2020

Two-dimensional transition-metal carbide MXenes has been known as a promising material of high-performance electrode for energy storage applications with both non-aqueous and aqueous electrolytes because it has electronic conductivity, ion capability in interlayer nanospace, and the redox activity of Ti. Especially, as an electrode of electrochemical capacitors, MXenes have a unique dependence of capacitance on intercalated cation species and a distinctive behavior that is both capacitive and pseudocapacitive depending on the electrolyte. To better understand electrochemical mechanism of these behaviors, we performed a microscopic theoretical analysis of the electric-double layer (EDL) in the interlayer nanospace of the MXene electrode by combining first-principles calculations based on density functional theory (DFT) and classical implicit solvation theory named three dimensional reference-site interaction model (3D-RISM) method [1]. By using the quantum-classical hybrid simulation, solvation effect at the interlayer nanospace of MXene electrode was taken into consideration appropriately with low computational cost comparable with conventional DFT simulation.
For the unique dependence of capacitance on intercalated cation species, our simulation results showed that the capacitance of EDL capacitors can be enhanced by a factor of 1.8, when the water molecules are strongly confined into the two-dimensional nanoslits of titanium carbide MXene electrode. This is because that dipolar polarization of strongly confined water overscreens an external electric field applied on the EDL and enhances capacitance with a characteristically negative dielectric constant of a water molecule [2, 3].
Another investigated feature is the distinctive behavior that is both capacitive and pseudocapacitive depending on the electrolyte. As a result of their electronic states simulated via the quantum-classical hybrid simulation, it was found that the hydration shell of intercalated ions prevents orbital coupling between MXene and the intercalated ions, which leads to the formation of an EDL and capacitive behavior. However, once the cations are partially dehydrated and adsorbed onto the MXene surface directly, because of orbital coupling of the cation states with the MXene states, particularly for surface-termination groups, charge transfer occurs and results in a pseudocapacitive behavior [4].
References
[1] S. Nishihara, and M. Otani, Phys. Rev. B 96, 115429 (2017).
[2] A. Sugahara, Y. Ando, S. Kajiyama, K. Gotoh, K. Yazawa, M. Otani, M. Okubo, and A. Yamada, Nat. Commun. 10, 850 (2019).
[3] K. Kim, Y. Ando, A. Sugahara, S. Ko, Y. Yamada, M. Otani, M. Okubo, and A. Yamada, Chem. Mater. 31, 5190 (2019).
[4] Y. Ando, M. Okubo, A. Yamada, and M. Otani, Adv. Func. Mater. accepted (2020).