bluuebunny/crossref_metadata_2025_split huggingface dataset:
Forced Air-Cooling Strategies for Lithium-Ion Batteries Using Integral Wake Splitters and Flow Guide-Vanes
Authors: Ismailov Kiarat , Adair Desmond , Massalin Yerzhan , Bakenov Zhumabay 
Published: February 2020

Thermal management of lithium-ion battery modules needs to be an integral part of the design process to guarantee that temperatures remain within a narrow optimal range. A well designed thermal management system will ensure good battery performance, safety and higher capacity. Many methods have been used, including air, liquid (direct and indirect), insulation, phase-change material, passive (ambient) or active (heaters, air-conditioning), or, a combination of these various approaches. In addition to regulating the module within a given temperature range, it is also important to minimize uneven distribution of temperature throughout the module. To not do so would decrease battery life cycle, and, charge and discharge performances.
This paper explores the use of surfaces extended into the near-wake of cylindrical lithium-ion cells, here termed integral wake splitters, and, of placing flow guide vanes also placed in the vicinity of the near-wakes. The numerical experiments are carried out in the Reynolds number range 102 - 103. After initially simulating flow and thermal characteristics in the vicinity of an isolated Li-ion cell, which includes optimizing the wake splitter length (L) - to - cell diameter (D) ratio, and, the gap (W
g) between flow guide vanes in the wake and their placement distance downstream of the cell (W
d) , the study expands to examining the effect of using cell arrangements on the thermal characteristics within a given module with optimized splitters and flow guide-vanes in place (Figure 1a and Figure 1b).
When using the integral wake splitters it is found that the local Nusselt numbers in the very near wake of a single cylindrical battery are depressed. Similar effects are found to occur when the battery cells are in formation. The use of flow guide vanes was found not to be as effective, but their use did contribute to a depressed Nusselt number.
Figure 1 Illustrations of the splitter plates (a) and flow guide vanes (b)

Figure 1
Simulation and Modelling of the Solid Electrolyte Interphase with Varying Porosity
Authors: Single Fabian , Karaca Erkmen , Horstmann Birger , Latz Arnulf 
Published: February 2020

Continuous capacity fade during the lifetime of lithium ion batteries is mainly attributed to the growth of the solid electrolyte interphase (SEI). This layer forms on the negative electrode and consists of electrolyte reduction products. Active lithium that is consumed in this reduction reaction is no longer available for the primary battery function, leading to capacity fade. By preventing direct electrolyte/electrode contact, the SEI layer can suppress the electrolyte reduction reaction to a large degree. However, capacity fade and SEI growth still continue with a decreasing speed [1,2]. The fundamental mechanisms behind this continuous SEI formation are still subject of active research.
Numerous models attempt to describe this effect [2-4]. They typically assume that the formation rate is limited by a single transport mechanism that allows one reactant to cross the SEI layer. While most of these models predict the experimentally observed SEI thickness and capacity decay, they remain inconclusive with respect to the limiting transport process. We present and evaluate the results of a new model to describe the SEI growth. Our model instead is based on two rate limiting processes and contains a spatially-varying porosity. This novel approach allows us to track the growth of the SEI morphology distribution.
Our simulations agree nicely with experiments [2] after adjusting the limiting transport parameter. Most importantly, the SEI thickness shows the characteristic √t growth behavior. The porosity inside the SEI is found to be constant. We derive analytic expressions for the thickness evolution and the attained porosity. These well justified estimates are in very good agreement with simulations.
[1] A.J. Smith, et al, Journal of the Electrochemical Society, 158 (2011), A447.
[2] M.B. Pinson, et al., Journal of the Electrochemical Society, 160 (2012), A243-A250.
[3] H.J. Ploehn, et al., Journal of the Electrochemical Society, 151 (2004), A456.
[4] J. Christensen, et al., Journal of the Electrochemical Society, 151 (2004), A1977.

Figure 1
(Invited) Pluse Plating for Compound Semiconductor Electrodeposition
Authors: Stickney John Lewellen , Czerniawski Justing , Zhang Xiaoyue , Bui Nhi , Shen Sheng 
Published: February 2020

Work in this group has mostly involved development of the electrochemical version of atomic layer deposition (E-ALD) over the last many years. ALD refers to is a group of methods for the formation of materials an atomic layer at a time using surface limited reactions. E-ALD achieves atomic level control during electrodeposition by alternating solutions and using underpotential deposition (UPD) to limit deposits to an atomic layer each cycle. It has been shown to form high quality deposits for a range of materials central to thin film photovoltaic formation, including: CdTe, CdS, CIS, and CIGS. Growth chemistry for a family of absorber materials referred to as CZTS, or Cu2ZnSn(S,Se)4 is presently being investigated. The primary advantages of CZTS for PV are that they are made from nontoxic earth abundant elements. The primary advantage of an E-ALD process would be atomic layer control and conformal deposition. The main disadvantage would be the time it takes to grow a µm thick absorber layer. The rate of growth is presently limited by the time it takes to alternate solutions.
Recently, efforts by this group have involved development of a variant of E-ALD based on potential changes (pulses), rather than solution exchanges, greatly increasing the rate of deposition. Presently, this group refers to this method as potential pulse ALD (PP-ALD). Preliminary results on the formation of Cu2Se and other components of a CZTS absorber layer will be discussed.
Electrochemical Oxygen Separation Using Layered Double Hydroxides As Hydroxide Ion Conductor
Authors: Tadanaga Kiyoharu , Arishige Yuji , Hayashi Akitoshi , Tatsumisago Masahiro 
Published: February 2020

Oxygen separation membranes using oxide ion conducting materials have been studied for oxygen separation from air. However, the membrane can effectively separate oxygen from the air only at high temperatures higher than several hundred degrees, because the oxide ion conductor shows high ionic conductivity at only elevated temperatures.
On the other hand, we have been studied layered double hydroxide (LDH) as a hydroxide ion conducting material [1-3]. LDHs are consisting of positively charged metal hydroxide layer and interlayer anions for charge compensation of cationic layer. The general formula for LDHs is [MII
1−x MIII
x(OH)2][(An−)x/n • mH2O], where MII is a divalent cation such as Ni2+, Mg2+, Zn2+, etc., and MIII is a trivalent cation such as Al3+, Fe3+, Cr3+, etc., and An− is an anion such as CO3
2−, Cl−, OH−, etc. We have recently reported that LDHs intercalated with CO3
2- showed high ionic conductivity of the order of 10-3 S cm-1under humidification, and the LDHs are solid hydroxide ion conductors [1-3].
Here we report the development of an electrochemical oxygen separation process using a hydroxide ion conductor [4]. The electrochemical oxygen separation cell consists of pelletized OH− conductive solid electrolyte and electrodes. At the air feed side, oxygen in air, H2O and electrons produces OH- ions at the electrode with the electrochemical oxygen reduction reaction. At the same time, oxygen, H2O and electrons are generated from OH− ions at the other electrode with the electrochemical oxygen evolution reaction. Since H2O will easily be separated with O2, oxygen separation will be achieved.
In this study, Ni-Fe LDH intercalated with CO3
2− (Ni-Fe CO3
2− LDH) was used as a hydroxide ion conductive material. The pellet of Ni-Fe CO3
2− LDH as an electrolyte was sandwiched with electrodes using Pt/C as a catalyst and Ni-Fe CO3
2− LDH as an ionomer. The oxygen concentration at the O2 product side was determined using a gas chromatography system. The electrochemical oxygen product flow was confirmed to be proportional to the external current density at 50oC under 70% of relative humidity, indicating that the membrane functioned as electrochemical oxygen separator.
[1] K. Tadanaga, Y. Furukawa, A. Hayashi, M. Tatsumisago, Adv. Mater., 22 (2010) 4401-4404.
[2] Y. Furukawa, K. Tadanaga, A. Hayashi, M. Tatsumisago, Solid State Ionics, 192(2011) 185-187.
[3] D. Kubo, K. Tadanaga, A. Hayashi, M. Tatsumisago, J. Electroanal. Chem., 671 (2012) 102-105.
[4] Y. Arishige, D. Kubo, K. Tadanaga, A. Hayashi, M. Tatsumisago, Solid State Ionics, 262 (2014) 238-240.

Figure 1
(Invited) Advanced CMOS Device Technologies Discussed Also with Transition-Metal Di-Chalcogenide (TMDC) Channel
Authors: Wakabayashi Hitoshi 
Published: February 2020

Abstract

Advanced CMOS device technology for a high-performance system-on-a-chip (SoC) LSI is firstly discussed by using benchmarking of published data [1-6], mainly-highlighted by a FinFET and beyond, as shown in Fig. 1. To enhance the performance of FinFET devices, a low-voltage operation less than 0.7 V with smaller variability of characteristics is highly required rather than an enlargement of channel width (Weff / Wfootprint). Here, Weff and Wfootprint mean effective and footprint channel widths. After that, higher-mobility channel devices are strongly needed with superimposed manner having an InGaAs high-electron mobility transistor (HEMT), InGaAs quantum well (QW), InAs QW, and InGaAs MISFET having an appropriate smaller bandgap. In this case, smooth thin-channel is promising to suppress the variability of characteristics. Therefore, an atomically-consistent semiconductor material such as a graphene and transition-metal di-chalcogenide (TMDC) are favorable candidates. Although the graphene has a zero band-gap, the TMDCs have superior properties such as an appropriate bandgap, for example, 1.2 eV in single-layer MoS2 film. Furthermore, they also yield higher mobility, transparent and mechanical robustness.
In our experiments, a higher Hall mobility of electron with 28 cm2/Vs in 10-nm-thick MoS2 film is achieved even by using a magnetron sputtering process with MoS2 target for channel formation [7]. This might be caused by a suppression of carrier scattering due to contaminations such as alkali metals of sodium and potassium, impurities, crystal defects, and film roughness in the MoS2 film.
In conclusion, the TMDC-channel MISFET could be suitable for high-performance SoC LSIs as not only advanced CMOS devices but also monolithic transistor to enhance the functionalities per chip area. Furthermore, it has a strong possibility achieving not only more-Moore and more-than-Moore but also more-comfort properties for high-performance human-interface (I/F) devices such as a transparent and flexible display.

Acknowledgements

This work was partially supported by JSPS Grant-in-Aid for Scientific Research on Innovative Areas: Grant Number 26105014, and the Center of Innovation Program from Japan Science and Technology Agency, JST.

References

[1] C.-H. Jan, et al., in IEDM, p. 44, 2012.
[2] S. Natarajan, et al., in IEDM, 3.7, p. 71, 2014.
[3] M. Radosavljevic, et al., in IEDM, p. 319, 2009.
[4] Alireza Alian, et al., in IEDM, p. 437, 2013.
[5] S.W. Chang, et al., in IEDM, 16.1, p. 417, 2013.
[6] J. A. del Alamo, et al., in IEDM, p. 578, 2014.
[7] Takumi Ohashi, Hitoshi Wakabayashi, et al. “Multi-layered MoS2 film formed by high-temperature sputtering for enhancement-mode nMOSFETs,” in 2015 Jpn. J. Appl. Phys. 54 04DN08, doi:10.7567/JJAP.54.04DN08.
(Keynote) Heterogeneous Integration of MEMS by Adhesive Bonding
Authors: Esashi Masayoshi , Tanaka Shuji 
Published: February 2020

Technology called microsystems or MEMS (micro electro mechanical systems) has been developed and applied as value added devices for systems. It is based on semiconductor microfabrication integrating not only circuits but also sensors, actuators and microstructures.
MEMS as switches and filters fabricated on CMOS LSI are needed for future multi-band wireless systems, in which good mechanical properties or piezoelectric materials are required for the MEMS and state of the art for the LSI. Such heterogeneous integration can be performed by transferring MEMS devices fabricated on a carrier wafer to a LSI wafer by adhesive bonding (Figure). Wafer level selective transfer from one carrier wafer to multiple target wafers are needed for cost-effective integration of different size chips. The selective transfer technology was applied to multiple SAW (surface acoustic wave) resonators on LSI and tunable SAW filter having variable ferroelectric capacitor.
Distributed tactile sensors are needed on the skin of robots to ensure their safety in nursing care robots. A tactile sensor network acquires sensing data from each tactile sensor element by autonomous data transmission (event driven). Capacitive tactile force sensors were formed on a communication LSI by adhesive bonding.
An electron emitter array integrated with a 100×100 active-matrix driving LSI has been developed using the adhesive bonding. Massive parallel EB (electron beam) exposure systems for maskless lithography (digital fabrication of LSI) are under development. A nc (nanocrystalline)-Si emitter consists of cascaded tunnel junctions can be controlled at low voltage (10V). Resist patterning by the emitted electron was successfully confirmed.
Amperometric biosensor in which 20×20 boron doped diamond electrode array are formed on LSI using the adhesive bonding. Distribution of chemicals like neurotransmitter can be detected owing to a wide potential window of the diamond electrode.
Cost effective development is required for micro systems because they are versatile and not standardized. A hands-on access fabrication facility in our University is reuse of a production line for power transistor and donated equipments. Companies can easily access and utilize for their prototyping or small-volume production. It is equipped with 4 and 6 inch facilities. The users are charged depending on their amount of usage. They can access a lot of technology and know-how accumulated and can be assisted by skilled engineers. More than 150 companies are using this facility and it is allowed to sell produced small volume devices.

Figure 1
Synthesis and Electrochemical Characterization of a Sodium Manganese Oxide By Facile Reduction Reaction for Sodium Ion Batteries
Authors: Song Jinju , Gim Jihyeon , Kim Sungjin , Jo Jeonggeun , Alfaruqi Muhammad Hilmy , Park Sohyun , Yang Juhyun , Kim Jaekook 
Published: February 2020

A non-stoichiometric composition of sodium manganese oxide (NaxMnO2+δ) cathode useful for sodium batteries was synthesized by an ambient temperature strategy that involves the facile reduction of aqueous sodium permanganate in sodium iodide and subsequent heat treatment at 600 °C. A combined powder X-ray diffraction (PXRD) and synchrotron X-ray diffraction (SXRD) analyses confirmed the annealed sample to belong to a NaxMnO2 phase with a P2-hexagonal structure. The ICP results confirmed the stoichiometry of the sample to be Na0.53MnO2+δ. Electron microscopy studies revealed the particle size of the electrode to be in the range of a few hundred nanometers. The Na0.53MnO2+δ cathode delivered average discharge capacities of 170 mAhg-1 with a stable plateau at 2.1 V for the initial 25 cycles versus sodium. Ex-situ XANES studies confirmed the reversible intercalation of sodium into Na0.53MnO2+δ and suggested the accommodation of over-stoichiometric Mn4+ ions to contribute towards electrode performance.

Figure 1
(Invited) Integration of 2-D Materials for Electronic Device Application
Authors: Jia Jianyuan , Jeon Jaeho , Park Jin-Hong , Lee Sungjoo 
Published: February 2020

In this work, we present our recent progresses on the integration of 2-d materials (TMD, BP, TMC) for the electronic device application.
In spite of the recent heightened interest in molybdenum disulfide (MoS2) as a two-dimensional material with substantial bandgaps and reasonably high carrier mobility, a method for the layer-controlled and large-scale synthesis of high quality MoS2 films has not previously been established. Here, we demonstrate that layer-controlled and large-area CVD MoS2 films can be achieved by treating the surfaces of their bottom SiO2 substrates with oxygen plasma process. In addition, by using various polymers, we present that the doping level of MoS2 layers can be controlled for realization of electronic devices.
Black phosphorous (BP) is known as a most stable allotrope of phosphorous. Recent studies have shown that BP is an elemental layered material, making it possible to obtain layered structures through mechanical cleavage. In this study, we report the preparation of thickness-controlled few-layer black phosphorus (BP) films through the modulated plasma treatment of BP flakes. Not only does the plasma treatment control the thickness of the BP film, it also removes the chemical degradation of the exposed oxidized BP surface, which results in enhanced field-effect transistor (FET) performance.
ZnCdSe-Sensitized WO3 and TiO2 based Photoelectrodes: A Comparative Study
Authors: Gakhar Ruchi , Chidambaram Dev 
Published: February 2020

After about four decades since Honda and Fujishima’s electrochemical photolysis report using TiO2(1), intensive research is still ongoing to identify efficient and cost effective semiconductor materials to be integrated in a photoelectrochemicalsystem. The ultimate goal is to have such a design that can simultaneously drive, both the hydrogen evolution and water oxidation reactions. Among all candidate materials, inexpensive metal oxides have been the primary choice due to their stability and excellent corrosion resistance.(2) However, the major drawback is their poor optical absorption that restrains solar-to-hydrogen efficiency to only few percent (3).
The best research strategy is to focus on a thermodynamically stable system with appropriate absorption properties and then attempt to improve its absorption, transport and catalytic properties. A stable tungsten based material with appropriate band edge alignment was chosen and the change in its band gap in the presence of a transition metal dopant was theoretically calculated. Based on the preliminary calculations, an optimal concentration of dopant was chosen and the material was synthesized via spray deposition. Surface morphology of the films (before and after sensitization) was examined using scanning electron microscope.Composition of substrate and oxidation state of elements was analyzed using X-ray diffraction and X-ray photoelectron spectroscopy. Absorption characteristics were determined using UV-Visible spectroscopy. Photoelectrochemical measurements (photocurrent/ photovoltage versus time and I-V characteristics) were undertaken to depict the photoconversion efficiency of designed photoanodes. The correlation of morphological changes with photoelectrochemical response of doped-oxide nanostructures will be discussed. Stability studies of the oxide films, conducted using ICP-OES, will also be presented.
Our results show that the bandgap can be altered significantly by using different dopants. Furthermore, for a given dopant, the synthesis parameters such as composition, film thickness, temperature, and dopant concentration play a significant role in determining the final characteristics.

Acknowledgements: This work was funded by Department of Energy under contract DE-FC36-06-GO86066. Dr. David Peterson and Dr. Eric Miller act as the program manager and the technical manager, respectively.

References

1. A. Fujishima and K. Honda, Nature, 238, 37 (1972).
2. N. M. Gaillard, in Meeting Abstracts, p. 1741 (2012).
3. N. Gaillard, Y. Chang, J. Kaneshiro, A. Deangelis and E. Miller, in SPIE Solar Energy+ Technology, p. 77700V (2010).
(Invited) Transistors without Semiconductors By Functionalized Boron Nitride Nanotubes
Authors: Yap Yoke Khin 
Published: February 2020

The development of one- and two- dimensional (1D and 2D) electronics are still facing various materials challenges. For instance, the nanotube-based electronics is still hindered by the chiral-specific synthesis of semiconducting carbon nanotubes (CNTs). On the other hand, the zero band gap of graphene is preventing their use in digital switches. Likewise, the structurally analog boron nitride nanotubes (BNNTs) and boron nitride nanosheets (BNNSs) are insulators and not applicable for electronic devices [1, 2]. Apparently, further development of nanoscale electronics will continue to rely on semiconducting nanowires and 2D nanosheets.
In this invited talk, I will discuss about the discoveries of 1D and 2D electronics without using semiconducting nanomaterials:
1) First, the use of BNNTs functionalized with gold quantum dots (QDs-BNNTs) as room-temperature tunneling field effect transistors (T-FETs) will be reviewed [3].
2) Next, the perspective of using QDs-BNNTs as flexible electronics will be evaluated based on our latest study using in-situ scanning tunneling microscopy performed inside transmission electron microscopy (STM-TEM).
3) Finally, I will discuss about effective digital switching of graphene as functionalized with BNNTs.

Acknowledgement:

This work is supported by the U.S. Department of Energy, Basic Energy Sciences, Materials Sciences and Engineering Division (DE-SC0012762) and the Center for Nanophase Materials Sciences (Project CNMS2012-083).
[1]. (Review) J. Wang et. al, Nanoscale 2, 2028 (2010).
[2]. C. H. Lee, et. al, Chem. Mater. 22, 1782 (2010).
[3]. C. H. Lee, et. al, Advanced Materials 25, 2544 (2013).
[4]. (Review) J. A. Jaszczak et. al. MRS Proceedings, 1700, mrss14-1700-mm03-01 (2014).
(Invited) Low Dimensional Materials Used for Solar Cells
Authors: Li Meicheng 
Published: February 2020

Low dimensional materials, including nanoparticles, nanowires and nanosheets have been widely used in the field of light harvesting, and energy conversion. Based on our work, we will introduce several low dimensional materials, and their application in the device of energy conversion, especially in solar cells. Detail information will coming later.
The low dimensionall materials offer a viable pathway to reduce fabrication costs and material usage, their energy conversion efficiencies can still be improved significantly by enabling them to harness a larger fraction of the incident solar photons, using new antireflection surface structure and even some new concepts, which can dramatically boost the amount of light trapping and light absorption per unit volume of semiconductor materials. The structural design and fabrication of these nanomaterials are essential for the further exploration of their functions.