bluuebunny/crossref_metadata_2025_split huggingface dataset:
Luminescent Characteristics of Fluorescent Organic Pigments Doped Recycled Polyethylene Thin Films Deposited by Ultrasonic Spray Technique at Low Temperature
Authors: Alarcon-Flores Gilberto , Sanchez-Alarcon Raul Ivan , Carmona-Tellez Salvador , Aguilar-Frutis Miguel Angel , Campos-Arias Martha Patricia , Falcony Ciro 
Published: February 2020

Fluorescent organic pigments (FOP´s) doped recycled polyethylene (PE) thin films were synthesized by using the ultrasonic spray technique at low temperature. With the objective of minimizing the environmental impact caused by plastic wastes, a new recycling scheme for the fabrication of luminescent polymeric thin films was designed. The recycled plastic bags of Low Density PolyEthylene (LDPE) were used as hosts for the FOP's. The process consisted of spraying an organic solution of LDPE on glass substrates. Later the FPO`s solution was sprayed on top of the LDPE thin films. Several deposition conditions were varied (deposition time, precursor concentration and substrate temperature) to form homogeneous and uniform films. The substrate temperature was low (180°C) in order to avoid thermal degradation of the polymer, as revealed by infrared spectroscopy. These films were doped with different FOP's. Emissions such as blue light emission (λ=434 nm), orange light emission (λ=503 nm) and green light emission (λ=503nm) were obtained by photoluminescence. These FOP´s were mixed to obtain white light emission polymeric films. The thicknesses were close to 1µ. According to Scanning Electronic Microscopy, the LDPE films consisted of small-superposed clusters and the FOP´s were adhered of them. The optical transmission was shown in the 60-80% range.

Acknowledgments
The authors acknowledge the financial support from SIP-IPN and CONACyT through the scientific research projects (Grant Nos. 20140458, 20140459, 20131915, 20130236, 20130153, 20121399, 129227).
Visualization of Mg2+ Electrochemical Insertion/Deinsertion into MnO2: Ex-Situ TEM Study
Authors: Song Jaehee , Noked Malachi , Lee Sang Bok 
Published: February 2020

Magnesium-ion (Mg-ion) rechargeable batteries are perhaps one of the most promising candidates that could potentially replace the current lithium ion battery technology. While the low cost and stability of magnesium make the Mg-ion battery an attractive technology, the divalent charge of Mg2+ ion brings in several significant scientific questions: How the divalent charge of Mg2+ affects their insertion/deinsertion behaviors? How far can Mg2+ ions penetrate into the bulk of the electrode material? One of the best ways to answer these questions is to visualize the Mg2+ insertion/deinsertion to/from the electrode material.
In this work, we visualized the process of the electrochemical insertion and deinsertion of Mg2+ into a MnO2 nanowire electrode by utilizing transmission electron microscopy (TEM) technique and electron energy loss spectroscopy (EELS). MnO2 nanowires were electrochemically grown within an aluminum anodized oxide (AAO) template. The obtained free-standing MnO2 nanowire array showed well-ordered, uniform structure and excellent contact with the current collector. These features of electrodeposited MnO2 nanowire electrode are beneficial for various imaging analyses as they would provide consistent results throughout the measurements. Moreover, this MnO2 nanowire electrode does not require conductive additives or a polymer binder solution to fabricate the electrode, therefore clear images of the nanowire samples can be obtained with no interferences from such additives.
From the ex-situ TEM energy dispersive X-ray spectroscopy (EDS) analysis, we found that the Mg2+ insertion is mostly confined to the surface of MnO2 nanowires. In order to observe the distribution of Mg2+ ions within the MnO2 nanowire in more detail, the discharged MnO2 nanowire array was sliced via microtome and its cross-section was analyzed by EELS. The EELS analysis on the cross-section of the discharged MnO2 nanowire showed that Mg2+ is also found at the center of the MnO2 nanowire, but at a lower degree than the surface. Moreover, we found that almost all of the inserted Mg2+ is retracted after charging the MnO2 electrode. This work not only presents interesting Mg2+ insertion/deinsertion behavior with MnO2, but also provides a systematic method that can be applied for the analysis of other cation/electrode systems.
Oxidative Stable Cu
3
Sn Nanoparticles for Novel Electrode Fabrication Using Pressure Under Ambient Condition
Authors: Cho Sanghun , Lim Keon-Hee , Yoo Jeeyoung , Park Si Yun , Park Youngmin , Kim Youn Sang 
Published: February 2020

Manufacturing methods of conductive electrode is essential technology for printable electronics such as radio frequency identification tags (RFID), thin film transistor (TFT), ultra high frequency antennas and solar cell. Various fabrication methods of electrodes for printable electronics have been suggested to screen printing, gravure printing and inkjet printing. However, these methods have difficulties to the control of printing pressure, thickness, nozzle blocking, viscosity of ink and coffee ring effect. New technique for electrode for printable electronics needs to perform at room temperature and ambient condition.
In addition, copper nanoparticles are good prospective candidate to replace high cost silver because of low-cost, abundant deposit and high conductivity. However, copper nanoparticles have the limitation which is highly oxidative materials and these drawbacks limited practical printing process. To overcome these limitations, conductive materials for electrodes requires high oxidative stable nanoparticles and low cost materials. In this study, we synthesized high oxidative stable, conductive Cu3Sn Nanoparticles and fabricated electrode by pressure assisted method at room temperature and ambient condition.
Prepared Cu3Sn nanoparticles were confirmed using X-ray diffraction (XRD) and Energy Dispersive X-ray Spectrum (EDS) with High Angle Annular Dark-Field Scanning TEM (HAADF-STEM). Measurement of electrical conductivity was carried out with the 4-point probe methods depending on various value of pressure. The conductive electrodes were obtained by pressure at 530MPa and showed electrical resistivity of less than 19.8 µΩ cm. Electrical resistivity of fabricated electrodes is similar to that of bulk Cu3Sn material (8.8. µΩ•cm). This result is caused by numerous and three dimensional contact of each conductive nanoparticle. To investigate the contact of each nanoparticle, Cross-sectional TEM analysis of pressed nanoparticles was performed. Also, we analyzed oxidation stability of nanoparticles by XRD and change of conductivity during 4 weeks in harsh condition (50% RH, at 25 oC). XRD and conductivity variation results showed no significant degradation. From these results, Cu3Sn nanoparticles have highly stable against air oxidation.
In conclusion, we synthesized high oxidative stable, conductive Cu3Sn Nanoparticles and fabricated electrode by pressure assisted method at room temperature and ambient condition. The Cu3Sn nanoparticles were stable in air due to the low Gibbs free energy and have very low price. Pressure assisted method promotes the contact of each particle which induce low electrical resistivity at room temperature and ambient condition. We believe that Cu3Sn nanoparticles and pressure assisted method for fabrication of electrode make a great contribution to TFTs, Solar Cell and RFID for electronics.
Studies on Dielectric Properties of Annealed Reactively Co-Sputtered Bcn Thin Films
Authors: Prakash Adithya , Sundaram Kalpathy B 
Published: February 2020

The main concern in the Ultra Large Scale Integrated (ULSI) semiconductor devices is the reduction of signal propagation delay. This delay ( ) is the product of electrical resistance of wiring metal and the parasitic capacitance of the Inter dielectric layer (IDL). The motivation behind the boron carbon nitride (BCN) ternary compounds is their similarities in the structure and difference in properties between graphite and hexagonal boron nitride (h-BN). Both theoretical calculations and experimental studies show that BCN compounds exhibit excellent mechanical, optical and electrical properties [1], [2]. It has been reported that the addition of carbon atoms to BN films is effective in reducing the dielectric constant. Also the structure of BCN film has a strong impact on dielectric constant [3]. The BCN deposition by chemical vapor deposition (CVD) has been reported [4], but in this work reactive co-sputtering is performed to deposit BCN thin films. The co-sputtering helps in the creation of films which gives more freedom to vary the composition when compared to single target sputtering. Thickness uniformity and the film quality are better when using co-sputtering.
In this work, we are depositing BCN thin films on oxidized silicon wafer substrates using two targets namely B4C and BN using RF power and DC power respectively at different N2/Ar gas flow ratios. A thin film of titanium (Ti) was deposited on it and another layer of Aluminum was deposited on top of the titanium layer to form a metal/insulator/semiconductor (MIS) device. This titanium layer acts as the barrier layer against the aluminum migration into BCN at higher temperatures during annealing. The dielectric constant value was found from capacitance-voltage (C-V) characteristics.
REFERENCES
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[2] A. Perrone, A.P. Caricato, A. Luches, M. Dinescu, C. Ghica, V. Sandu, A.Andrei , Appl. Surf. Sci., 133 (1998), p. 239
[3] T.Sugino, Y. Etou, T. Tai, Jpn. and H. Mori, Appl. Phys. Lett. 80, 649 (2002)
[4] J. Yu and E. G. Wang, Appl. Phys. Lett. 74, 2848 (1999)
Unique Layered Tin Oxide Structure Via Buffered Anodization
Authors: Mohri Nils Erich Karl , Tremel Wolfgang 
Published: February 2020

The electrochemical anodization of various metals (e.g., Al [1], Ti [2] and Fe [3]) is able to generate a great variety of nanostructures. In the last decade, these new nanomaterials have received intensive interest due to their high technological potential in many applications such as photocatalysts for organic degradation [4], self-cleaning substrates [5] and solar cell electrodes [6, 7].
Tin dioxide (SnO2) is an n-type semiconductor used as solid-state gas sensor [8] and oxidation catalyst [9]. It also has the potential to function as high capacity anode material for lithium-ion batteries [10]. Jeun et al. [11] synthesized irregular nanoporous tin oxide films in 0.3 M oxalic acid solution at 6 V and used it as a gas sensor material.
Anodization of tin in oxalic acid solutions at an applied voltage of above 5 V produces highly porous tin oxide structures. Lower applied voltages, as investigated by Yang et. Al [12], result in a passivation of the surface by precipitation of tin-oxalate.
We investigated the use of a buffer solution to prevent the precipitation of tin oxalate unto the surface. This enabled us to anodize tin at lower applied voltages resulting in a completely new tin / tin dioxide layer structure.
After optimizing the parameters, we investigated the growth mechanism and various chemical, physical and biological applications of this new structure.
Literature:
[1] H. Masuda, K. Fukuda, Science 268 (1995) 1466
[2] D. Gong, C.A. Grimes, O.K. Varghese, W. Hu, R.S. Singh, Z. Chen, E.C. Dickey, J. Mater. Res. 16 (2001) 3331
[3] T.J. LaTempa, X. Feng, M. Paulose, C.A. Grimes, J. Phys. Chem. C 113 (2009) 16293
[4] K. Lee, D. Kim, P. Roy, I. Paramasivam, B. Birajdar, E. Spiecker, P. Schmuki, J. Am. Chem. Soc. 132 (2010) 1478
[5] E. Balaur, J.M. Macak, H. Tsuchiya, P- Schmuki, J. Mater. Chem. 15 (2005) 4488
[6] O.K. Varghese, M. Paulose, C.A. Grimes, Nat. Nanotechnol. 4 (2009) 592
[7] G.K. Mor, K. Shankar, M. Paulose, O.K. Varghese, C.A. Grimes, Nano Lett. 6 (2006) 215
[8] P.G. Harrison, C. Bailey, W. Azelee, J. Catal. 186 (1999) 147
[9] G. Croft, M.J. Fuller, Nature 269 (1977) 585
[10] Y. Wang, J.Y. Lee, H.C. Zeng, Chem. Mater. 17 (2005) 3899
[11] J.-H. Jeun, H.-S. Ryu, S.-H. Hong, J. Electrochem. Soc. 156 (2009) 263
[12] M. Wang, Y. Liu, D. Zhang, H. Yang, Electrochim. Acta 59 (2012) 441
Hydrogenated TiO2 Nanotubes as High-Power Anode Materials for Lithium-Ion Batteries
Authors: Eom Ji-Yong , Yun Ju-Ho , Yoo Seung-Eul , Ryu Won-Hee , Lim Sung-Jin , Kwon HyukSang 
Published: February 2020

Titanium oxide (TiO2) has received much attention as the most promising alternative to the conventional graphite anode of Li-ion batteries for high energy and power. The performance of TiO2 anode for Li-ion batteries depends strongly on the crystalline phase, the morphology, and the porosity of the structure. The nanostructured TiO2 materials, such as nanoparticles, nanorods, nanowires, and nanotubes have been studied to improve the performance of TiO2 anode. Recently, it was reported that the hydrogenated TiO2, called a ‘black TiO2’ nanostructures are more attractive for photovoltaics, photocatalysis, and supercapacitors owing to their narrower bandgap (less than typical 3 eV value) and relatively high electrical conductivity.
The smooth and well-ordered TiO2 nanotubes were synthesized on a Ti disk successfully by anodization in a non-aqueous solution containing fluoride ions. The as-prepared TiO2 nanotubes were annealed to obtain crystalline anatase (A-TiO2 NTs) and hydrogenated TiO2 nanotubes (H-TiO2 NTs) at 450 °C for 2 h in air and hydrogen atmosphere, and then their electrochemical performances were investigated as alternative anode materials for Li-ion batteries.
The initial discharge capacity of the H-TiO2 NTs (0.117 mAh cm-2) was superior to that of the A-TiO2 NTs (0.110 mAh cm-2) and the discharge capacities of the H-TiO2 NTs and A-TiO2 NTs maintained nearly 72 and 44 % at a current density of 10 mA cm-2. In addition, the H-TiO2 NTs (89 %) exhibited much higher the capacity retention than the A-TiO2 NTs (70 %) at the current density of 1 mA cm-2 (~10 C-rate) after 300 cycles, as shown in Figure 1. The H-TiO2 NTs presented smaller the crystallite size and charge transfer resistance (Rc) compared with the A-TiO2 NTs and the oxygen vacancies were formed in the H-TiO2 NTs during hydrogenation, which was proved by the presence of Ti3+ from the XPS analysis.
These results indicate that the insertion and extraction of Li+ through the H-TiO2 NTs were preferable to those through the A-TiO2 NTs, which were probably attributed to the short diffusion length for Li+, innumerable reaction sites, and relatively high electrical conductivity. Therefore, the H-TiO2 NTs exhibited vastly superior the rate capability and capacity retention property during cycling to the A-TiO2 NTs at high current density as anode materials for Li-ion batteries.
Synthesis and Lithium Storage Properties of Novel Flower-like Co3O4
Authors: Liu Peng , Xia Xifeng , Wang Wenjuan , Hao Qingli 
Published: February 2020

Cobalt oxide, Co3O4, one of the most important metal oxides and p-type semiconductor, has been found wide spread applications in many important fields, including solar cell photo-catalysts and supercapacitors or lithium-ion batteries. Usually, properties of the material depends on its special morphology. Different morphologies of cobalt oxide such as cubes, sheets, wires and tubes have been synthesized[1][2].
In this work, a novel flower-like Co3O4 has been produced by calcining the precursor, which was obtained through a simple hydrothemal method. The unique hierarchical architecture is able to shorten Li+diffusion paths and accommodate the volume change of the materials during charge/discharge process. Electrochemical evaluation demonstrates its potential application as anode material for lithium ion batteries. Fig. 1 shows the cycle life of cobalt oxide, the inserted picture a and b are the TEM images of precusor and cobalt oxide, respectively.
references：
[1] Lou X W, Deng D, Lee J Y, et al. Advanced Materials, 2008, 20(2): 258-262.
[2] Tian L, Zou H, Fu J, et al. Advanced Functional Materials, 2010, 20(4): 617-623.
Entropy of Cycled and Aged Li-Ion Batteries for Maritime Conditions
Authors: Vie Preben J. S. , Mæhlen Jan Petter , Kirkengen Martin 
Published: February 2020

Electrification with Li-ion batteries is a global trend that has been on-going for many years across sectors, driven by a strong decrease in battery prices, increasing energy density and increasing fuel costs. Studies by DNV of the electrification of ships (e.g. Fellowship) have shown a large potential of reduction in energy consumption and emissions of CO2, NOx and particulate matters through electrification [1]. In addition, cost calculations have shown the possibilities for return of investment through electrification within 3 years for some applications, more recent data states even 2 years for other applications [1].
It is well-known that the safety of Li-ion batteries is an important issue. E.g. during over-charge of a Lithium-ion battery, the battery may eventually overheat and cause a thermal runaway which can ignite neighboring cells which have not been overcharged. Internal shorting of the electrodes is also reported to create thermal runaway situations. Based on the large amounts of energy in a 1 MWh Li-ion battery, it is absolutely vital that the safety of the battery system is assured. The degradation and ageing of Li-ion batteries will contribute to additional instability and affect the safety performance of the batteries as well. Hence, knowledge and the ability to predict capacity decay and the battery state of health will be vital information to enable safe and long-life operation of marine battery systems.
In this study commercial Li-ion cells were studied with the entropy spectroscopy technique [2, 3] to establish a State-of-Health indicator for aged cells. The cells tested were Li-ion pouch cells which have been aged for both calendar and cycle life up to 3 years.
For cycle life, the Li-ion cells were evaluated at various temperatures and charge and discharge rates. The calendar life was scrutinized at various temperatures and at different state of charge. The cells were characterized, based on continuous monitoring of capacity and energy content. In addition, periodic capacity and impedance data was recorded for all cells at the same temperature (25 °C) and discharge rate (1C).
1. Vartdal, B.-J. and C. Chryssakis, Potential Benefits of Hybrid Powertrain Systems for Various Ship Types, in International scientific conference on hybrid and electric vehicles, RHEVE 20112011: Rueil-Malmaison, France. p. 12.
2. Reynier, Y., R. Yazami, and B. Fultz, The entropy and enthalpy of lithium intercalation into graphite. Journal of Power Sources, 2003. 119: p. 850-855.
3. Viswanathan, V.V., D. Choi, D. Wang, et al., Effect of entropy change of lithium intercalation in cathodes and anodes on Li-ion battery thermal management. Journal of Power Sources, 2010. 195(11): p. 3720-3729.
Comparative Electrochemical Study of Metal Oxalate As Anode for Lithium Batteries
Authors: Oh Hyo-Jin , Kim Sun-Jae , Myung Seung-Taek 
Published: February 2020

Rechargeable lithium ion batteries (LIB) are the most advanced power sources for portable electronic devices, hybrid electric vehicles, transportation sectors and military applications. Metal oxalate is technologically important and functional material, because of its applications for use in energy storage such for Li ion batteries. Thus, these materials have been investigated as alternative negative materials for LIB owing to high capacity (700 ~ 1,000 mAhg-1) based on a conversion mechanism.
Several metals based oxalates with different aspect ratios have been synthesized by hydrothermal reaction of metals (= Ni, Co, Mn) with Na2C2O4 and H2O in the presence of ethylene glycol (EG). Control over the aspect ratios of oxalates were achieved by adjusting the hydrothermal reaction temperature and time.
The electrode was fabricated by mixing 70 wt% active material, 10 wt% carbon black (electronic conductive additive) and polyacrylic acid (PAA, binder) in N-methylpyrrolidinone (20 wt%). A solution of 1 M LiPF6 dissolved in a mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) (3 : 7 weight ratio) was used as the electrolyte in the cell. Electrochemical test was carried out in coin type cell. Galvanostatic electrochemical charge and discharge test were made between 0V and 3.0V at 100 mAg-1 current at room temperature.
The hydrothermal method is useful to synthesize metal oxalate with particles and crystallization. Nickel and manganese oxalate crystallize in the monoclinic phase, while the cobalt compound adopts the orthorhombic phase.
The as-prepared metal oxalates demonstrate a high performance as anode material for LIB. Among them, nickel oxalate showed a high initial discharge capacity of 1321 mAhg-1. The first charge capacity of the as-prepared electrode at a current density of 100 mAg-1 reach 786 mAhg-1 with good capacity retention.
Failure Mode Analysis of Li-Ion Batteries Using in-Situ Scanning Electron Microscopy
Authors: Hovington Pierre , Lagacé Marin , Marceau Hugues , Clément Daniel , Dontigny Martin , Trottier Julie , Guerfi Abdelbast , Mauger Alain , Julien Christian M , Zaghib Karim 
Published: February 2020

High cycle life is a key parameter for any lithium-ion battery technology to obtain a commercial success. In this regard, multiple electrochemical (Impedance, ASI, floating current, etc.) and non-electrochemical techniques (XRD, FT-IR, SEM/TEM, etc.) are used and developed. The most complete techniques involve measurements while the battery is cycling (in-situ experiment). Among them, in-situ SEM/TEM is able to focus on the same region/particle at all steps of the oxidation/reduction process. Hydro-Quebec has developed a complete expertise for in-situ techniques, especially in situ SEM.
Lithium Polymer Battery (LPB), a solid-state battery, is the preferred configuration for SEM in-situ experiment. We present in Figure 1 micrographs taken during in-situ experiments of a Li/PEO-based solid polymer electrolyte (SPE)/Li1.2V3O8 LPB showing the variation in thickness for the Li, SPE and cathode layers with the cell voltage. Only the Li thickness shows an important variation during cycling. The Li plating rate can also be measured. This experiment can clearly be used to better understand the Li plating mechanism.
In figure 2 we present micrographs taken during an in-situ SEM cycling of a Li/PEO-based SPE/SiO cell using backscattered electron signal. We clearly see an important decrease in the beam intensity of the back-scattered electrons (BSE) as a function of the cell voltage as a result of the Si phase transformation upon cycling (upon Li ‘insertion’, the BSE intensity is lower and the particle becomes darker). We also note that a region of the big particle remains white (i.e. the Li+ ions did not have sufficient time to ‘diffuse’ inside their core region). This result explains the rather low capacity observed with such particles, and it gives evidence that the system is out of thermodynamic equilibrium. This in-situ experiment also shows no cracking of the relatively big SiO particles since the voltage was kept higher than 0.1V (stop at the Li22Si7 phase instead of Li22Si5) when compared to previous results [1]. We will also present in-situ SEM of nano-Si particles that did not suffer any cracking, but agglomerate (electrochemical sintering), which results in a more rigid and fractured electrodes [2]
This presentation will also use in-situ SEM to obtain a better understanding of the failure mechanism of new electrode materials, including Li-S.
References:
[1] http://batt.lbl.gov/blog/research-tasks/in-situ-sem-seeing-battery-cycling-in-action/?utm_source=rss&utm_medium=rss&utm_campaign=in-situ-sem-seeing-battery-cycling-in-action
[2] Hovington et al, (2014) ‘in situ Scanning electron microscope study and micriostructural evolution of nano silicon anode for high energy Li-ion batteries’, Journal of Power Sources 248, 457-464