bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microstructure Characteristics of Blend Cathodes Assessed By 3D-Tomography Methods
Authors: Costard Janina , Joos Jochen , Ivers-Tiffée Ellen 
Published: February 2020

Electrode performance of lithium ion battery cathodes is strongly affected by its microstructure parameters. FIB (focused ion beam) / SEM (scanning electron microscopy) tomography is a powerful tool for determining microstructure parameters. The application of this method and processing of images has been optimized for battery electrodes [1], enabling an accurate detection of the three components (1) carbon black, (2) pore phase and (3) active material. A special challenge is to distinguish between different active materials which are combined in blend electrodes for optimizing their performance and energy density.
In this study, a dual beam modus is applied for analyzing the composition and microstructure of a blended battery cathode consisting of three active materials (NMC, NCA and LMO). By combining the information of InLens and Everhart-Thornley detector it was possible to reconstruct a volume of 35µm x 37µm x 20µm consisting of 1010 x 1070 x 570 voxel (isotropic voxelsize of 35 nm). The pore phase and the carbon black were segmented by evaluating images acquired using the Everhart-Thornley detector, due to lower falsification by local charging, whereas the active material was separated into its three components interpreting information of InLens detector which provides a better contrast of specific material. It was possible to clearly assign the three materials, confirmed by EDX analysis, and to calculate microstructure parameters for every specific component, as particle size distribution, active surface area, porosity and tortuosity.
Limiting factor for an application of this method is the representative volume element size which is dependent of the number of active materials as well as their maximum particle size, as reported in [2] for solid oxide fuel cells. For prospective studies, an increased reconstruction volume is necessary while maintaining high resolution of images, which is challenging with regard to FIB-procedure as well as processing of big data amount. Alternative tomography methods as X-ray tomography enable the reconstruction of larger volumes, but suffer from low contrast of carbon black and limited resolution.
Advantages and disadvantages of the different tomography methods are discussed and assed.
[1] M. Ender, J. Joos, T. Carraro and E. Ivers-Tiffee, Journal of the Electrochemical Society, 159, A972-A980 (2012)
[2] J. Joos, M. Ender, T. Carraro, A. Weber and E. Ivers-Tiffée, Electrochemica Acta,
82, 268-276 (2012)
Understanding Why Sodium Intercalated Graphite Is Unstable
Authors: Moriwake Hiroki , Kuwabara Akihide , Fisher Craig Andrew James , Nose Masafumi , Nakayama Hideki , Nakanishi Shinji , Iba Hideki , Ikuhara Yuichi 
Published: February 2020

Sodium-ion batteries offer a potential solution to the problem of limited lithium resources, although developing compatible, high-performance cathode, anode, and electrolyte materials for such devices presents a more difficult challenge. In conventional lithium ion batteries, graphite is used as the anode, but it has been known for more than 40 years from experiment that, unlike the other alkali metals (Li, K, Rb, and Cs), intercalation of Na into graphite is thermodynamically unfavorable, so that modification of the anode material or addition of solvating species is needed if intercalation is to occur. First-principles calculations by Nobuhara et al. [2] and Wang et al. [3] showed that even at low Na densities NaC
x
compounds are energetically unstable. However, the underlying mechanisms responsible for the endothermic formation energies are still uncertain. To investigate this phenomenon in more detail we performed first-principles calculations of the intercalation behavior of alkali metals into graphite. A van der Waals correction was added to the standard density functional theory methods to better reproduce the laminated structures of graphite intercalated compounds. Calculated formation energies of intercalated systems XC6 (X = Li, Na, K, Rb, or Cs) are shown in Fig. 1(a). As the atomic number decreases from Cs to Na, the magnitude of the formation energy decreases, becoming positive (endothermic) in the case of Na. This tendency can be explained in terms of ionic bonding energies, which decrease as the atomic number of the alkali metal decreases because electronegativity increases as the alkali metal group is ascended. The reason for the negative formation energy in the case of LiC6 can be understood by examining the electron density and density of states, plotted in Fig. 1(b), which show greater covalent bonding between Li and C than the other alkali metals.
References
[1] K. Kim, et al., Energy Environ. Sci., 8, 2963 (2015).
[2] K. Nobuhara, H. Nakayama, M. Nose, S. Nakanishi, and H. Iba, J. Power Sources, 243, 585 (2013).
[3] Z. Wang, S. M. Selbach, and T. Grande, RSC Adv., 4, 4069 (2014).

Figure 1
Differential Thermal Voltammetry As a Low Cost in-Situ Diagnosis Tool for Lithium-Ion Batteries
Authors: Merla Yu , Wu Billy , Yufit Vladimir , Brandon Nigel P. , Martinez-Botas Ricardo , Offer Gregory James 
Published: February 2020

Modern applications of batteries in portable electronics, electric vehicles and grid level energy storage, demands long lifetime in various operating conditions. Monitoring its state-of-health in real time and optimising its operation in a cost-effective manner presents a real challenge.
Differential thermal voltammetry (DTV) is a novel in-situ diagnosis technique for tracking degradation in lithium-ion batteries based on relatively simple cell surface temperature measurements. DTV only requires temperature and voltage measurements and is carried out by measuring the change in cell surface temperature during a constant current charge or discharge. It is a complimentary method to the incremental capacity or slow rate cyclic voltammetry analysis as it has additional information on the entropy characteristics as a result of temperature measurements.
Accelerated aging experiment was carried out on commercial lithium-ion cells where the cells were aged differently in a controlled environment. The cells were characterised regularly using the new technique. Each dT/dV peak in the resulting curve represents a combination of different contributions from positive and negative electrode phases (Figure 1). By decoupling these peaks and by monitoring the evolution of the peak parameters it is possible to quantitatively determine stoichiometric drift in the cell. Cell 1 which was stored at 55degC and held at 4.2V showed significant shift in electrode stoichiometry. On the other hand, cell 2 stored at 55degC and cycled at 1C showed little shift despite the similar capacity fade of approximately 10%.
This novel application of DTV presents an opportunity to estimate the state of health of a lithium-ion battery through tracking of decoupled dT/dV peaks. These results can then feed in to adaptively control the cell operation based on the diagnosis to optimise cell lifetime and available energy. Its low software and hardware requirements make it a practical solution to existing and future systems.
Figure 1. Decoupled dT/dV peaks for two aged cells at approximately 10% capacity fade. Cell 1 (left) was stored at 55degC and held at 4.2V. Cell 2 (right) was stored at 55degC and cycled at 1C. Schematics of combined phases are shown above each plot. Note the visible stoichiometric drift in cell 1.
[1] Y. Merla, B. Wu, V. Yufit, R.F. Martinez-botas, N.P. Brandon, G.J. Offer, Novel application of differential thermal voltammetry as an in-depth state of health diagnosis method for lithium-ion batteries, J. Power Sources. 307 (2016) 308–319. doi:10.1016/j.jpowsour.2015.12.122.
[2] B. Wu, V. Yufit, Y. Merla, R.F. Martinez-botas, N.P. Brandon, G.J. Offer, Differential thermal voltammetry for tracking of degradation in lithium-ion batteries, J. Power Sources. 273 (2015) 495–501. doi:10.1016/j.jpowsour.2014.09.127.

Figure 1
Exploring Different Concepts for 2D Cu Growth on Ru(0001) Assisted By Pb UPD Monolayer
Authors: Wu Dongjun , Brankovic Stanko R 
Published: February 2020

The properties of heteroepitaxial thin films are much dependent on the method used for their deposition. The electrodeposition represents the ambient temperature process offering the opportunity to grow many heteroepitaxial metal overlayers while preserving the integrity of their interface. In recent years, a significant progress has been made in understanding the kinetic aspects controlling the growth modes [[i],[ii],[iii]]. The improved understanding has led to various discoveries in which the growth kinetics was manipulated to enhance the evolution of atomically flat epitaxial overlayers [[iv],[v],[vi]]. Exploiting some of these results has led to development of several new methods and protocols for electrodeposition of heteroepitaxial thin films assisted by UPD monolayer serving as a mediator, surfactant or sacrificial template. [[vii],[viii],[ix],[x]].
In this talk we will briefly review the progress in the electrochemical thin film growth assisted by UPD ML. Our focus is examining the epitaxial growth of Cu on Ru(0001) assisted by Pb UPD ML. Cu and Ru represent the overlayer/substrate system which has significant epitaxial strain (-5.5%). This fact together with room temperature growth conditions favor a 3D growth. However, as we will show in our talk (Figure 1), with convenient use of Pb UPD ML serving as surfactant, or mediator, a 2D growth of Cu on Ru is induced. Characterization of 2D Cu overlayers indicates that their quality is comparable to MBE grown films which qualifies our approach as relevant for many high-tech applications. Our results also re-confirm the fact that Pb UPD ML-assisted electrochemical growth could be used to produce smooth 2D films of various metal overlayers even in situations where both thermodynamics and kinetics conditions do not favor positive outcome.
The authors acknowledge the support from NSF Chemistry division under the contract # 0955922.

[i] Physics of Crystal Growth, A. Pipinelli and J. Villain, University Press, Cambridge, UK (1998).
[ii] J. Tersoff, A.W. Denier van der Gon, and R.M. Tromp, Phys. Rev. Lett. 72, 266 (1994).
[iii] G. Rosenfield, B. Polesma and G. Comsa in Chemical Physics of Solid Surfaces ed. D. A. King and D. P. Woodruff, vol. 8, Elsevier, New York (1997), p. 70.
[iv] G. Rosenfeld, R. Servaty, C. Teichert, B. Poeselma and G. Comsa, Phys. Rev. Lett., 71, 895 (1993).
[v] H. A. van der Vegt, H.M. van Pinxteren, M. Lohmeier, E. Vlieg and J.M.C. Thornton, Phys. Rev. Lett. 68, 3335 (1992).
[vi] H. A. van der Vegt, H.M. van Pinxteren, M. Lohmeier, E. Vlieg and J.M.C. Thornton, Phys. Rev. Lett.
68, 3335 (1992).
[vii] K. Sieradzki, S.R. Brankovic and N. Dimitrov, Science,
284, 138 (1999).
[viii] S. R. Brankovic, Electrochemical Mediated Growth, PhD Thesis, Arizona State University, Tempe (1999)
[ix] S.R. Brankovic, N. Dimitrov and K. Sieradzki, Electrochem.Solid-State Lett., 2, 443 (1999).
[x] S.R. Brankovic, J.X. Wang and R. R. Adzic, Surf. Sci., 474, L173 (2001).

Figure 1
Cobalt-Palladium Alloys for Hydrogen Generation Via Water Electrolysis
Authors: Kutyla Dawid , Kolczyk Karolina , Kowalik Remigiusz , Mech Krzysztof , Zabinski Piotr 
Published: February 2020

The d-Block metals such as cobalt and nickel are widely applied in chemical industry as catalysts in reactions producing, among others, liquid or gaseous fuels. The best parameters are featured by precipitation catalysts modified with precious metals. Due to a very high price of platinum metals, it is important to search for solutions that could lower their quantity while maintaining similar catalytic properties.
An innovative approach is the use of a magnetic field to modify the crystalline structure of coatings, which, especially for ferromagnetic elements, can improve their catalytic properties.
Magnetic field applied parallel to the surface of the electrode generates convection of the electrolyte; it results in a laminar flow on the surface of the electrode which reduces the diffusion layer and increases the concentrations gradients. This results in change of the size of the grains and thus can also influence the texture and formation of various phases of the deposits. These various effects can be caused at the same time by the above mentioned convection but also by the magnetic properties, when the field is superimposed the growth in the direction of easier magnetization appears.
Optimal composition, structure and morphology of cobalt matrix alloys with respect of hydrogen evolution performance will be sought through selection of proper composition of electrolyte, changes of electrolysis parameters and by application of external electromagnetic field with intensity up to 12 Tesla.
Effects of Additives on Performance of Zinc Air Battery
Authors: Wu Ching-Chen , Huang Shih-Hsuan , Hsueh Kan-Lin , Chang Wen-Sheng , Yang Chang-Chung 
Published: February 2020

Abstract

Appropriate energy storage plays a very important role in a wide range of applications, including frequency regulation of renewable energy sources, peak-shaving of electrical grid, emergency power, and portable power. Metal-air batteries have long been a subject of research since they can be used in many applications, such as small batteries for watches, acoustical devices, and as large batteries for electric vehicles. There is a wide variety of applications for zinc metal as high capacity anodic material in the secondary alkaline batteries due to its high specific energy, good reversibility, environmental friendliness, low equilibrium potential, low cost, and no-toxicity.
During battery charging, formation of zinc dendritic deposits in alkaline electrolytes severely decreases the cycle life of zinc rechargeable batteries. Uneven current density distribution, local concentration gradient variation, preferential crystalline growth of zinc causes the formation of dendrites. In order to suppress the dendritic growth, many inorganic additives such as CdO, PbO, Pb3O4, In2O3, and Bi2O3 have been tested. To decrease the hydrogen production potential, organic materials also have been studied, such as, poly vinyl alcohol (PVA), triethanolamine (TEA), ethylene-diamine-tetra-acetic acid (EDTA), poly-oxye-thylene sorbitan mono-laurate (Tween 20) and tartaric acid.
In this study, the electrochemical behavior of zinc deposition in electrolyte with various additives is investigated by cyclic voltammetry (CV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). The corrosion behavior of zinc in alkaline solution with different additives is also studied. The morphologies and crystalline structures of various Zn deposits are examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. We found that zinc dendrite was eliminated by addition of EDTA and Tween 20. Same components can also improve the stability of zinc in alkaline solution. This work was supported by Bureau of Energy, Ministry of Economic Affairs.

Key word: zinc dendrite, corrosion, solution additives
The Characteristics of the Bismuth Telluride Based Materials Via Gas Phase Reaction Method
Authors: Koo Hye Young , Ha Gook Hyun 
Published: February 2020

Bismuth telluride based alloys powders are well known as thermoelectric materials near room temperature in 200~450K. Thermoelectric effect is direct conversion between thermal and electrical energy. Thermoelectric generator has several advantages such as eco-friendly (reusing the waste heat), reliable source of energy, simple maintenance, no-noise, long life time etc. But the low convert energy efficiency and high unit cost of production is still problem to solve. Energy conversion efficiency is involved with figure of merit ZT (ZT=σS2T/κ) where σ is the electrical conductivity, S is the Seebeck coefficient, T is the absolute temperature, κ is the total thermal conductivity. To enhance the energy conversion efficiency of thermoelectric materials, stoichiometrically dispersed powders within fine sized one particle has an advantage because of its composition uniformity. Spray pyrolysis is well known process as gas phase reaction method. The effects of the morphological, electrical and thermal properties of thermoelectric materials prepared by spray pyrolysis were investigated in this study. The phase of powders and bulk were analyzed by X-ray diffraction (XRD). The microstructures of powders and bulk were characterized by field emission scanning electron microscopy (FESEM). The thermoelectric properties of bismuth telluride based materials were analyzed using ZEM-3 (Ulvac-Rico) and thermal conductivity were calculated by the thermal diffusivity measured by the laser flash method (LFA457, Netzsch).
Using of Finite Elements Modeling Computer Simulation in Impedance Prediction and Data Evaluation
Authors: Vanýsek Petr , Vyroubal Petr , Novák Vitězslav 
Published: February 2020

With the electrochemical impedance measurement capability becoming more and more standard in the present day electrochemical instrumentation, the technique is also being introduced in experimentation and more routinely at that. While the danger of misinterpretation based on analogs derived from equivalent circuits remains as it always has been, the occurrence of such interpretation is increasing because the impedance nonlinear least square fitting procedures are often included in the instrumental software package and allow mechanical modeling without requirement of deeper understanding the fundamentals. While this is natural consequence of the mass availability, some undesirable outcome may be for example alleviated by closer attention to the chosen sample geometry.
The sample geometry and the location of the electrodes (often four, in the 4-point measurement) is crucial in collecting proper impedance data, interpretation of the impedance measurements, and correlating the results to the properties of the studied material. As an example, the included picture shows a simulation of resistance as it would be measured on a rod (left) of a varying length. The rod has a radius of 14 mm and the contact electrode (“zero resistance”) covers the entire cross sectional bottom of the rod. However, the upper electrode, placed on the axis of the rod, has a radius of only 7 mm, thus only area under the electrode is covered. The graph on the right shows the calculated measured resistance, divided by the rod length, as a function of the length of the rod. If the upper electrode covered the entire cross section, then the value of such resistance should be constant (expected, but also verified by a simulation). However, with the upper electrode smaller, the scaled resistance is higher for thinner disks (shorter rods) and then it decreases, reaching a limiting constant value for long rods. This value corresponds to the value calculated, for any distance, for rods with electrodes completely covering both ends. The simulation for this work was done using the ANSYS software package.
In our experimental work the impedance measurements that we perform on doped conducting ceramics, the electrode placement is extremely crucial as the samples are thin disks and the advantage of the long rods cannot be utilized. We will demonstrate some experimental measures that we utilized to maintain uncertainly arising from the geometry issue minimal.
Acknowledgement
This research has been financially supported in part by the Ministry of Education, Youth and Sports of the Czech Republic under the project CEITEC 2020 (LQ1601), under NPU I program (project No. LO1210) and the COST project LD15068.

Figure 1
Practical Evaluation Method of Oxygen Precipitation in the Czochralski Silicon
Authors: Lee Anselmo Jaehyeong , Hong Sejun , Kim Ja-Young , Kang Hee-Bog , Lee Sung-Wook 
Published: February 2020

Oxygen precipitates in Czochralski silicon (CZ-Si) are still considered as the major process-induced defects found in semiconductor device fabrication process because the role of oxygen precipitates in device process such as gettering of metal impurity, prevention of undesired wafer deformation, and degradation of carrier lifetime is quite significant to manufacture high-performance devices. Until now, various theoretical models to predict the oxygen precipitation in CZ-Si with respect to the interstitial oxygen (Oi), vacancy (CV), and the process temperature T have been suggested. However, the complexity and calculation time of a model strongly depend on the accuracy of the model. Thus, it is difficult to apply them on the evaluation of oxygen precipitation regularly in conventional wafer production. Hence, a practical and simple method to evaluate oxygen precipitation should be proposed.
In this work, we derived the parameters that indicate the thermal stability and formation rate of the precipitate nuclei by analyzing as-grown oxygen precipitates formed in a p-type CZ-Si. First, we calculated a cumulative distribution function (CDF) of as-grown precipitate density with respect to the thermal history of CZ-Si crystal from the theoretical nucleation rate J(Oi, CV, T) [1]. After that, we fitted the CDF mathematically into the temperature-dependent precipitate density measured after slow ramped anneals with 1 K/min [2] at various stability temperatures followed by a growth anneal at 1000°C for 16 hours. Moreover, the first derivative Je
(T) of the CDF was also calculated which was associated with an effective nucleation rate. The extreme point (T
C, Je
(TC)) on the Je
(T) was determined as a new parameter that represents the precipitate behavior at a measured point. Finally, we correlated the parameters to the experimental results measured in various crystals after the test heat cycle started at 800°C for 4 hours and followed by 1000°C for 16 hours. As shown in Fig. 1, we found that both T
C and Je
(TC) were strongly correlated to the precipitate density, which means that the parameters were possibly applied to evaluate the behavior of oxygen precipitation in a crystal after various thermal processes.

Fig. 1 Correlation of the T
C (a) and Je
(T
­C) (b) to the precipitate density measured after 2-step annealing starts at 800°C for 4 hours and followed by 1000°C for 16 hours.
[1] G. Kissinger, D. Gräf, U. Lambert, and H. Richter, J. Electrochem. Soc.
144, 1447 (1997).
[2] G. Kissinger and J. Dabrowski, J. Electrochem. Soc.
155, H448 (2008).

Figure 1