bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Negative Electrode for Calcium Ion Battery Using Marimo Nano Carbon
Authors: Nishimura Yuichiro , Nakagawa Kiyoharu 
Published: December 2020

Lithium-ion batteries (LIBs) are used in various fields due to their high energy density and high cycle characteristics. In general, graphite materials are used for the negative electrode materials for lithium-ion batteries (LIBs). However, since the amount of Li ion that can be stored in the graphite material of the negative electrode is approaching the theoretical value for LIBs, a significant increase in capacity cannot be expected.
Calcium ion batteries (CIBs) use Ca ion as charge carriers. Therefore, they can be expected to have twice the capacity of LIBs. In LIBs, charge and discharge mechanism occurs by intercalation and deintercalation of Li ion into graphite layers. However, Ca ion are poor in reactivity, intercalation and deintercalation of Ca ion do not occur in the graphite negative electrode, and charge and discharge capacity cannot be obtained. For this reason, we used Marimo Nano Carbon (MNC) as a new negative electrode material. MNC is an aggregate of carbon nano filaments (CNF). CNF has a layered structure similar to graphite and also has amazing electronic properties and many other unique properties. This CNF has coin-stacked structure in which graphene layers are stacked, and the edge surface is exposed. Hence, we expected that MNC negative electrode would react with less reactive Ca ions and indicated larger charge / discharge capacity than that of the graphite negative electrode. In this study, we evaluated MNC negative electrode performance.
For MNC synthesis, nano metal particles carried on oxidized diamond were used. Oxidized diamond has oxygen-containing functional groups arranged regularly. Thus, nano metal particles are a highly dispersed on it. Pd metal was used for carried metal. Pd metal could synthesized CNF having coin-stacked structures. Pd metal was carried on oxidized diamond by metal nano-colloidal method. C2H4 as a feedstock for CNF was used, and MNC was synthesized by the chemical vapor deposition (CVD) method.
When MNC was used as the negative electrode material, the charge and discharge capacity was larger than that of the graphite negative electrode. In addition, the intercalation of Ca ions between the graphene layers was confirmed.
(General Student Poster Session Winner - 1st Place)Feasibility of LiNbO3 Surface Coating on High-Ni Layered Cathode Materials for Lithium Ion Batteries
Authors: Kim Jong Hwa , Choi Wonchang , Park Min-Sik 
Published: December 2020

Recently, lithium ion batteries (LIBs) have received great attention as a suitable power source for electric vehicles (EVs) because of its highest energy and power densities among currently available energy storage systems. For successful implementation the achievable energy density of current LIBs should be further improved to meet the industrial requirements. In this respect, the development of advanced materials is crucial for improving the energy density of LIBs. During the last decade, layered lithium transition metal oxides (e.g., LiMO2, M = transition metal) have been used as the most popular cathode materials in commercial LIBs [1]. From a structural point of view, Li+ can be reversibly inserted and extracted in the given structure based on the redox reactions of transition metals. Therefore, the choice of transition metals is crucial for determining the electrochemical properties of these cathode materials. By increasing the Ni concentration, the reversible capacity of the cathode materials can be effectively increased due to the double redox reaction of Ni2+/Ni4+. In practice, high-Ni layered cathode materials (Ni > 80%) can offer a high reversible capacity over 200 mAh g-1 [2]. As a result of increasing the Ni concentration, however, the cathode materials suffer from poor cycle performance and thermal stability mainly induced by side reactions with electrolyte and residual Li at the surface. To overcome these limitations, effective surface coatings are required to make the surface more stable and suppress undesirable side reactions [3]. Herein, we propose a surface coating with LiNbO3 onto NCM811 cathode material to minimize undesirable side reactions as well as improve the thermal stability [4]. Thanks to the high ionic conductivity and thermal resistance of LiNbO3, LiNbO3 coated NCM811 exhibit much improved cycle performance and rate capabilities even at high operating temperature of 60 oC. Moreover, we also investigate the effect of LiNbO3 crystallinity on the electrochemical properties of LiNbO3 coated NCM811. It would provide a practical guideline for the development of a highly reliable high-capacity cathode material for EV applications.
References:
[1] M. M. Thackeray, J. Electrochem. Soc. 142 (1995) 2558-2563.
[2] P. Hou, J. Yin, M. Ding, J. Huang, X. Xu, Small 13 (2017) 1701802.
[3] Z. Chen, D. Chao, J. Lin, Z. Shen, Mater. Res. Bull. 96 (2017) 491-502.
[4] M. Gellert, K. I. Gries, J. Sann, E. Pfeifer, K. Volz, B. Roling, Solid State Ion. 287 (2016) 8-12.
The Making and Baking of Coordination Polymers for Li-Ion Batteries
Authors: Shuaib Umaira , Indris Sylvio , Darma Mariyam Susana Dewi , Powell Annie K. 
Published: December 2020

As demand for efficient and sustainably clean energy has thrust global research towards proficient energy storage systems (ESSs), which are capable of accommodating large capacities, portable systems that have a high energy and power density have become significantly important. The increasing need for hybrid electric vehicles, electric vehicles and portable devices with longer and more stable battery life, has boomed the applications of lithium-ion batteries considering their safety and reliability make them the most promising ESSs currently available on the mass market. However, their high energy density and limited self-discharge is hindered by the use of graphitic anodes. Transition-metal oxides (TMOs) have plenty of applications across many different fields of science; solar cells, gas sensors and the electronics industry are some areas where the progression from research to application has been extremely rapid. Manganese oxides (MnOs) are a common and commercial active material used in the electrodes of energy storage devices such as batteries, because they have a higher theoretical capacity (756 mAh g-1) compared to the conventional anode material graphite (372 mAh g-1).
Here we present both a TMO anode material as well as the corresponding cost effective porous carbon as graphite replacements for lithium-ion cells that observe stability in both the capacitance and redox potentials. Templating the battery materials from coordination polymers allows a fraction of control of the resultant materials obtained post pyrolysis. The as-synthesized MOFs and clusters have a carbon content of c.a 50% . The resultant oxide has a carbon content of ...c.a X%. BET analysis of these materials alongside the porous carbon shows surface area increasing from X to Y to Z respectfully.
Electrochemical Properties of LiNiO2 Integrated with Nanosize Li3PO4
Authors: 池田 直広 , Yabuuchi Naoaki , Aita Taira 
Published: December 2020

The demand of EVs is growing in the world and further increase in energy density of lithium-ion batteries (LIBs) is required. Among positive electrode materials for LIBs, LiNiO2 and its derivatives have been considered as an alternative material to LiCO2 because of its high reversible capacity, good rate capability, and relatively low material cost.[1] Nevertheless, LiNiO2 without cobalt ions shows insufficient irreversibility especially upon charge to high voltage. In this study, nanosized Li3PO4 is integrated into LiNO2, which is synthesized by mechanical milling and post heat treatment, and is tested as a positive electrode material in Li cells. We also discuss the possibility of high-performance and Co-free electrode materials for LIBs.
A binary system of x Li3PO4 – (1 – x) LiNiO2 (x = 0, 0.03, and 0.05) with a rocksalt structure was synthesized by mechanical milling and used as a precursor. The precursor with a rocksalt structure was heated at 650 oC in oxygen, resulting in the formation of layered LiNiO2 integrated with nanosize Li3PO4 domains. Characterization of the samples was conducted by X-ray diffraction (XRD) and scanning electron microscopy (SEM). For the evaluation of electrochemical properties, composite electrodes consisting of 80 wt% active material, 10 wt% AB, and 10 wt% PVdF, were casted on aluminum foil. 1.0 M LiPF6 dissolved in ethylene carbonate (EC)/dimethyl carbonate (DMC) (3/7 by volume) solution was used as electrolyte.
XRD patterns of x Li3PO4 – (1 – x) LiNiO2 (x = 0.03 and 0.05) binary system after milling are assigned into the rocksalt structure that is a metastable phase. After heating, the crystal structure of the samples is changed into the layered phase, and a uniform distribution of Ni and P was confirmed from energy dispersive X-ray elemental mapping. This finding suggests that nanosized Li3PO4 is successfully integrated into LiNiO2. Figure 1 shows the galvanostatic charge/discharge curves of the samples cycled in the voltage range of 2.5 and 4.5 V at a rate of 10 mA g-1 in Li cells. Layered LiNiO2 without Li3PO4 (x = 0) delivers a discharge capacity of 210 mA h g-1 at initial cycle. However, capacity degradation is non-negligible upon further cycles. In contrast, the sample of x = 0.03 exhibits a slightly reduced capacity of 190 mA h g−1, but the significant improvement of cyclability is evidenced even electrochemical cycle with charge to 4.5 V. From these results, we will further discuss the impact of integration of nanosize Li3PO4 into layered LiNiO2 and the possibility of Co-free electrode materials in the future.

References

(1) Y.-K. Sun et al., ACS Energy Lett.
2, 1150, (2017).

Figure 1
Effect of Alloying Elements on Pit Growth in AA7075
Authors: Sampei Yota , Muto Izumi , Sugawara Yu 
Published: December 2020

AA7075 is known to a show high strength/weight ratio but suffers from localized corrosion, such as filiform corrosion, pitting, crevice corrosion, and stress corrosion cracking in Cl-containing environments. It has been proposed that Cu-containing intermetallics deteriorate the corrosion resistance and are the initiation sites of pitting. When AA7075 is immersed in an aqueous solution containing NaCl, the intermetallic compounds dissolve, and Cu-enriched particles are formed on and around the intermetallic compounds. Then, the Cu-enriched particles act as a cathode for the oxygen reduction and hydrogen generation reactions, and a strong alkali is locally generated. As a result, it is considered that the Al matrix dissolves, and local corrosion occurs. Therefore, alloy elements that suppress the cathode reaction on the Cu-enriched particles were studied.
The samples were prepared from the arc-melting of AA7075 and pure Sn. The concentration of Sn was changed from 0.1 to 5 mass%. After casting, the ingots were heated to 430°C and rolled to a thickness of 2 mm. A solution treatment was performed at 500°C for 2 h. After the heat-treatment, the sample surfaces were polished with a diamond paste down to 0.25 µm.
In order to characterize the shape and distribution of the intermetallic particles in the samples, the sample surfaces were observed with an optical microscope and SEM-EDS. The open circuit potentials of AA7075 were measured in 0.1 M NaCl adjusted to pH 6.0 for 16 h. The area exposed to the electrolyte was 10 mm × 10 mm. The measurements were performed in a naturally aerated solution, and Ag/AgCl (3.33 M KCl) was used as a reference electrode. After immersion, the sample surfaces were inspected. Anodic polarization curves of AA7075 were measured in 0.1 M NaCl adjusted to pH 6.0. The measurements were performed in the aerated solution, and the electrode area was 10 mm × 10 mm. In addition, that of pure Sn was also measured. The number of intermetallic compounds in AA7075 with 0.1 mass% Sn was low compared with AA7075. In the initial stage of immersion of AA7075 and Sn-added AA7075, the open circuit potentials were located approximately – 1.0 V and increased with time. Finally, the potential reached around – 0.7 V. The lower potential duration was prolonged by the Sn addition. After immersion, filiform-like corrosion and pitting were observed on the samples. In addition, the Al-matrix and the intermetallic compounds discolored by dissolution. The pitting potential of AA7075 and the 0.1 mass% Sn-added AA7075 alloy was -0.65 V, and no difference was observed.
First Principles Prediction of Corrosion Kinetics As a Function of Microstructural Features in Precipitation Hardened Aluminum Alloys
Authors: Li Sirui , Zhu Yakun , Taylor Christopher 
Published: December 2020

In this poster, first principles density functional theory (DFT) implemented in the Vienna Ab Initio Simulation Package (VASP)1 is coupled with micro-kinetic model2 to simulate the electrochemical corrosion kinetics of some commonly identified intermetallic particles3 (IMPs) associated with precipitation hardened aluminum alloys such as AA7075. First principles DFT calculation is used to characterize the adsorption energies for the cathodic reaction intermediates on intermetallic surfaces. The species include atomic oxygen (O) and hydroxide (OH) as intermediates for the oxygen reduction reaction. We will show that when coupling the thermodynamic calculations with an appropriate micro-kinetic model, we can predict the corrosion kinetics of IMPs. One of the most desirable properties obtained from the simulated polarization curve is the corrosion potential of the IMPs. The corrosion potential can indicate the relative nobilities of IMPs with respect to the alloy matrix. Experimentally the corrosion potential of IMPs on the range of microns are measured via a micro-capillary cell technique. With the state of the art TEM, localized corrosion even down to the nm scale can be characterized4. On the simulation side, however, a method that can be directly compared to experimental data has not yet been fully realized. Attempts to estimate corrosion potentials from the surface work functions obtained by DFT calculations have been made in recent literature but the direct correlation of work function to the corrosion potential has a significant band of uncertainty associated with it. Rather than finding direct correlation, we incorporate work function into the kinetics equation as one of the input parameters. Our simulated for Al7FeCu2, one of the most commonly identified IMP in high strength aluminum alloy, is -337 mVNHE, which is in good agreement with experimental data (-307 mVNHE). We contend here that a first-principles model founded in electrode kinetics is a promising path forward for bridging first-principles simulation and experiment in corrosion science.
Reference

G. Kresse and J. Furthmüller, Comput. Mater. Sci., 6, 15–50 (1996).

H. A. Hansen, V. Viswanathan, and J. K. Nørskov, J. Phys. Chem. C, 118, 6706–6718 (2014) http://pubs.acs.org/doi/abs/10.1021/jp4100608.

N. Birbilis and R. G. Buchheit, J. Electrochem. Soc., 152, B140 (2005) http://jes.ecsdl.org/cgi/doi/10.1149/1.1869984.

Y. Zhu et al., Acta Mater., 189 (2020).
Effect of Applied Voltage on Isotope Separation Factor By Electrodialysis Using Lithium Ion Conductive Electrolyte La0.57Li0.29TiO3
Authors: Shin-mura Kiyoto , Tokuyoshi Ryoya , Sasaki Kazuya 
Published: December 2020

Tritium, which is used as a fuel in a thermonuclear fusion reactor, is produced in the fusion reactor blanket by the reaction of neutrons with lithium whose 6Li-isotope-ratio is 90%. Other than the mercury amalgam method, which has a large environmental impact, no practical lithium isotope enrichment technology has been established. Electrodialysis using the lithium ion conductive electrolyte La0.57Li0.29TiO3 (LLTO) is promising, as reported to achieve high isotope enrichment [1]. In this study, we investigate the effect of applied voltage in electrodialysis on the isotope separation factor.
An anode (primary solution side) and a cathode (secondary solution side) were formed on both front and back surfaces of LLTO. One reference electrode was also formed on each surface of the LLTO. DC voltage of various magnitudes was applied between the anode and the cathode. The electrochemical impedance between the reference electrode on the primary solution side and the anode during the application of this voltage was measured by AC impedance spectroscopy. At the same time, the electrochemical impedance between each of the secondary solution side reference electrode and the cathode was also measured. The amount of transferred lithium and the isotope ratio of lithium were measured by an inductively coupled plasma mass spectrometer (ICP-MS).
The lithium isotope separation factor increased linearly with decreasing applied voltage. Here we assume the following: ① The existence probability of such atoms with respect to the minimum value of the energy required for lithium in the crystal lattice to move to the adjacent site has a normal distribution, ② In 6Li and 7Li, the standard deviation of the normal distribution is the same and the energy average the values are different. Then, in a narrow energy region near the activation energy of 6Li or 7Li transfer, it is expected that the ratio of 6Li in the energy transfer lithium decreases linearly with the increase in energy. Our experimental results seem to follow this prediction.
[1] S. Honda, K. Shin-mura and K. Sasaki, J. Ceram. Soc. Japan, 126, [5], 331-335 (2018).
Highly Stable Completely Non-Vacuum Process Multi-Porous-Electrodes-Layered Perovskite Solar Cell
Authors: Tsuji Ryuki , Bogachuk Dmitry , Luo Bin , Martineau David , Kobayashi Eiji , Funayama Ryoto , Mastroianni Simone , Hinsch Andreas , Itou Seigo 
Published: December 2020

Perovskite solar cells (PSCs) have achieved a photoelectric conversion efficiency of 25 % and can be manufactured only by printing and coating processes, so it expected to be commercialized. However, the organic materials used for PSCs are very unstable to water and oxygen, so long-term durability needs to be improved. Therefore, we focused on a PSCs having a three-layer structure of an electron transport layer (mesoporous TiO2), a spacer layer (mesoporous ZrO2), and a hole transport layer/electrode (Graphite). The scaffold layer of this carbon-based PCSs is manufactured by only printing, and the perovskite precursor solution is drop-cast from graphite layer and infiltration into the scaffold layer to complete the device. This PCSs can perform all of the fabrication processes under non-vacuum conditions. In addition, the thick graphite layer protects the power generation layer from the surrounding air and moisture, and has high long-term stability. In this study, in order to further improve durability and performance, PCSs were fabricated using a perovskite precursor solution using only inorganic materials under completely non-vacuum.
The conductive layer of the FTO glass was removed by etching and separated, and a compact TiO2 blocking layer was formed by spray pyrolysis deposition on the FTO glass. Then, TiO2 paste and ZrO2 paste were deposited by screen printing and sintering at 500 °C. Similarly, graphite paste was printed and sintering at 400 °C. Finally, a perovskite solution was instilled from the graphite layer, the solvent was removed by drying, and the perovskite was crystallized to complete the device. The PSCs was optimized by changing the composition of the paste used for each layer, the layer thickness, and the infiltration method of the perovskite precursor solution. Various material analyzes and solar cell performance evaluations were performed.
The thickness of each layer was controlled by changing the composition of the paste used for each layer and the ratio of the material to the solvent. It was found that the photoelectric conversion efficiency was highest when the TiO2 layer was around 500 nm and the ZrO2 layer was 1.5~2 μm. Also, by improving the infiltration of the precursor solution, the photoelectric conversion efficiency was greatly increased. The graphite paste used to form the graphite layer was made using several types of graphite, and we found the most suitable one for this solar cell.

Figure 1
Seebeck Properties of Sr8Ti7S21
Authors: Kamimizutaru Koki , Nagaoka Akira , Yoshino Kenji 
Published: December 2020

Depletion of natural resources and increasing global warming urge the researchers to develop new methods for energy harvesting. The global demand of alternative clean energy is becoming more and more drastic. The conversion of heat into useful electrical energy is an environmentally friendly and straight forward approach to solve the power problems. Thermoelectric materials have been considered to relieve the energy crisis based on the reversible heat and electricity conversion.
We have focused on a new chalcogenide thermoelectric material Sr8Ti7S21 which low lattice thermal conductivity is expected because of a large unit cell (a = 11.5 Å, c = 47.7 Å). However, there are few reports on fundamental and thermoelectric properties. Here, we report growth of Sr8Ti7S21 crystal by solid-state reaction and characterization of its thermoelectric properties. Sr8Ti7S21 polycrystalline sample can be obtained from growth temperature of 900 ºC. The conduction type shows n-type, and Seebeck coefficient of 234 μV/K at 323 K. These results make Sr8Ti7S21 a promising new thermoelectric candidate.
Study on ITO Fresnel Pattern Liquid Crystal Lens
Authors: Woo Jae Geun , Kang In Hye , Kim Seo Gwon , Kang Seok Jun , Bae Byung Seong 
Published: December 2020

Everyone is getting old and the presbyopia arise. Conventional presbyopia correction lenses include convex lenses and progressive lenses, each of which has advantages and disadvantages. The convex lens is a short focal length lens, which has the advantage of being able to see immediately when looking at the close, but has the disadvantage that the lens is thick, heavy, and the glasses have to be removed when looking at the distance. Progressive Lens is a multifocal lens that can focus from near to far. It is relatively thin compared to convex lenses, but requires an adaptation period of about 1 to 2 months. To solve this problem, we developed light, thin, and variable refractive index ITO Fresnel pattern lenses using liquid crystals.[1] ITO Fresnel patterns were formed by photo lithography, and the voltages were applied differently for each pattern to drive the liquid crystals, and the focal length was changed as the applied voltage changed. The diopter (D) of the lens has changed over 9V, and showed the maximum diopter of 1 at 13V.
[1] Li, Guoqiang, et al. "Switchable electro-optic diffractive lens with high efficiency for ophthalmic applications." Proceedings of the National Academy of Sciences 103 (16), pp.6100-6104 (2006)