bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation of Three-Dimensional Nitrogen-Doped Hollow Fiber Carbon and Its Application to Electrochemical Energy Device
Authors: Lim Katie Heeyum , Kim Hansung , Park Heeyoung , Park Hyun S. , Jang Jong Hyun
Published: February 2020

Three-dimensional nitrogen-doped carbon materials are prepared using thermally decomposable polystyrene(PS) and mussel-inspired polydopamine(PDA), as a sacrificial template and a nitrogen-doped carbon precursor, respectively. By virtue of the versatile coating ability associated with the high nitrogen content, dopamine was demonstrated to be an effective precursor for the preparation of nitrogen-doped carbon. In previous studies, PDA has been used as a nitrogen source by coating its layer onto a main carbon source. Herein, however, the PDA is utilized not only for the nitrogen precursor but also for the carbon source, without any additional carbon source, in order to achieve the higher nitrogen content and simple synthetic procedure. As a result, nitrogen content on carbon increased to over 4 at. %, which was limited to under 1 at. % when PDA was just coated onto the other carbon source. Moreover, due to highly moldable characteristics of polymer ingredients, three-dimensional carbon structures with various configurations could be prepared such as micron-sized hollow carbon fiber.

First, nitrogen-doped hollow carbon fiber with μm-sized diameter was synthesized by coating PDA around the electrospun PS fiber and following pyrolysis for PS removal and PDA carbonization. The length of hollow carbon fiber was also able to be controlled from several μm to hundreds of μm, using ultra-sonication. Completely hollow carbon fiber with about 3-μm diameter was successfully obtained and analyzed its physical characteristics from XPS, Raman and Mercury porosimeter. Nearly 4 at. % of nitrogen was detected on the hollow carbon fiber and the over 68 % of nitrogen-doping structure is revealed to be graphitic-N, which is known as the most effective nitrogen-doping structure for oxygen reduction reaction.

Since both PDA-derived carbon materials have relatively high nitrogen content and can form a self-supporting network, endowing high applicability as a binder-free electrode, they can be effectively applied to electrochemical energy device, specifically polymer electrolyte membrane fuel cell (PEMFC) and Li-O2 battery system where the oxygen reduction reaction is the dominant reaction.
Pencil Peel Derived Highly Porous and Conductive Activated Carbon for All-Solid-State 1.8 V Symmetrical Supercapacitors
Authors: Sundriyal Shashank , Shrivastav Vishal , Mishra Sunita , Kim Ki Hyun , Deep Akash
Published: February 2020

Activated carbon recycled from biomass resources are recently gaining attention for variety of applications due to their tunable pore size, high specific surface area and good electrical conductivity. Herein, we have synthesized highly porous and conductive activated carbon using commonly available and recyclable pencil peels. The pencil-peel derived activated carbon (PDAC) shows very high specific surface area and good conductivity, therefore becomes suitable to be used as an active electrode material for supercapacitors. The PDAC material is obtained at different temperatures viz. 700, 800 and 900 °C. Among them PDAC-800 shows highest specific surface area and hierarchal pore size while maintaining good conductivity. Due to these properties, PDAC-800 based electrode shows enormous electrochemical performance as compared to its other counterparts. The PDAC-800 electrode possesses high specific capacitance of 552.5 F/g at a current density of 1 A/g using 1 M H2SO4 aqueous electrolyte. Furthermore, an PDAC-800//PDAC-800 based all solid-state flexible symmetrical supercapacitor is assembled using two equally weighted PDAC-800 electrodes, which shows a wide potential window of 1.8 V. Therefore, the as fabricated solid-state device delivers a high energy density of 25.7 Wh/kg with a high-power density of 939.6 W/kg. Meanwhile, the device shows a long-term cycle life of 92.2 % after 5000 continuous charge-discharge cycles. A PDAC-800 based supercapacitor device in PVA-1 M H2SO4 polymer gel electrolyte with 1.8 V potential window is capable to power up a white LED for 3 minutes upon charging for 40 seconds. This work paves the way for the next generation energy storage technology and demonstrate its potential for future supercapacitor application.
Photosystem I-Modified Multi-Walled Carbon Nanotube Anodes for Enhanced Solar Energy Conversion
Authors: Stachurski Christopher , Dervishogullari Dilek , Stanley Jade , Wolfe Kody , Jennings G. Kane , Cliffel David E.
Published: February 2020

As renewable energy sources strive to match growing energy demands, new materials and designs constantly push the performance of preexisting solar cells to new levels. However complex patterning techniques or use of environmentally toxic materials limit the extent to which state-of-the-art designs can transition from research scale devices into commercially applicable devices. Biohybrid solar cells address this limitation by employing naturally occurring dyes or light harvesting protein complexes, such as photosystem I (PSI) in their design. In this work, multi-walled carbon nanotube (MWCNT)-coated electrodes have been modified with PSI to serve as high surface area anodes in an effort to enhance generated photocurrent. The chemical treatment of MWCNTs prior to deposition on conductive substrates resulted in uniform films and lead to a 7-fold enhancement in observed photocurrent compared to PSI-based devices assembled on unmodified, planar gold electrodes. This facile treatment and deposition of MWCNTs promotes their use in electrochemical devices as an inexpensive, robust, and high surface area alternative to other carbon allotropes.
Preparation of Metal-Gr Composite Coatings Via Electro-Plating for High Corrosion Resistances
Authors: Li Sishi , Yang Yanpeng , Song Gongsheng , Pan Chunxu
Published: February 2020

1) Preparation of Fe-Gr composite coating via DC electro-plating for high performances. In this work, the iron-graphene (Fe-Gr) composite layer was prepared by using an electro-plating method. The performance of the composite was varied with the concentrations of GO in the electrolyte. The layer’s microstructures were systematically characterized by SEM, TEM, Raman, FT-IR, and the micro-hardness and its corrosion resistance were evaluated for getting desired properties. The experimental results revealed that: 1) the Gr could be scattered homogeneously in the Fe layer when dispersible graphene oxide (GO) was added in the electrolyte; 2) comparing with pure Fe layer, the micro-hardness and corrosion resistance of the Fe-Gr composite layer were greatly enhanced; 3) it was found that there was an optimal GO addictive amount (0.4 g/L) in the electrolyte, which increased the properties involving the micro-hardness up to HV 248, 2.07 times higher than that of pure iron layer(HV 120); 3.75 times of anti-corrosion rate(0.1353 mmy-1) and 5.38 times of the charge transfer resistance(1456 /(Ω·cm2) higher than that of pure iron layer(0.5076 mmy-1, 270.5 /(Ω·cm2).

2) Preparation of Zn-Gr composite coating via pulse reverse electro-plating for high corrosion resistances. In this work, a kind of the Zn-Gr composite layer is successfully prepared on iron substrate via pulse reverse electro-plating method from a chloride aqueous solution. The experimental results revealed that: 1) By adding GO in the electrolyte, Gr sheets can be incorporated homogenously in the Zn plating layer during electro-plating, and the reduction from GO into Gr occurs due to the Zn and GO co-deposition. 2) Due to increasing of the nucleation sites, Gr incorporation changes the growth mechanism of Zn crystal, i.e., makes the main preferred orientations from (112) and (101) crystal planes in the pure Zn layer into (103), (102) and (110) planes in the Zn-Gr composite layers. 3) As a corrosion protection barrier layer, Gr sheets play an important role on the corrosion resistance of the Zn-Gr composite plating layers in simulated seawater environment. The highest corrosion resistant properties occur in an optimal range 0.3 – 0.5g/L GO adding amount in the electrolyte, at which the corrosion current density just be a hundredth comparing with that of pure Zn layer. 4) The present method for preparing Zn-Gr composite, with advantages of simple, controllable, scalable, etc., is likely to be industrialized.
Microstructure Effects on the Electrochemical Properties of Graphene/Manganese Oxide Porous Electrodes
Authors: Hamade Fatima , Radich James , Davis Virginia Angelica
Published: February 2020

Manganese oxide (MnO2) nanowires as guest hosts with ultra-large reduced graphene oxide (RGO) sheets form a sandwich structure and may provide electrochemical properties that cannot be achieved with either material alone. Ultra-large graphene oxide (GO) sheets exhibit an order of magnitude larger length to diameter ratio compared to most studies with smaller GO sheets (~70,000 compared to ~2,000) and demonstrate potential for improved electrode design. Understanding the self-assembly properties of the combination of MnO2 nanowires and ultra-large RGO sheets was explored by two methods: a) mixing both dispersions that have been synthesized separately to form a mixture and b) growing the nanowires along the ultra-large GO sheets to form a hybrid material. The pure and multicomponent dispersions were characterized by spectroscopy and microscopy techniques to characterize the materials and gain insight into their dispersion microstructures. The dispersions were then freeze-dried into aerogels with 3D porous architectures. Tuning the initial dispersion parameters, including concentration, MnO2 content, and assembly results in different morphologies and physical and electrochemical properties of the aerogels. Results from this work convey that the hybrid exhibits a more uniform distribution of the nanowires than that of the mixture and the porous electrodes consist of mesopores (diameters between 2 and 50 nm) with interconnected pathways. Furthermore, the electrochemical performance of the hybrid and mixture electrodes suggests that there may be stronger interfacial contact between the RGO sheets and MnO2 nanowires in the hybrid due to the nanowires’ nucleation and growth along the sheets as opposed to the mixture. Comparison of the dispersion and aerogel morphologies as well as electrochemical performance provided insights into the relationships between material type, initial dispersion microstructure, and electrode properties.
(Plenary) Layered Oxides in Li- and Na- Batteries: Structural and Electronic Effects
Authors: Delmas Claude
Published: February 2020

At the end of the 70’s, Huggins, Whittingham, Murphy, Armand and then Rouxel research groups open the way to reversible Lithium batteries with aprotic liquid electrolytes. Most of the researches was devoted to chalcogenides at the positive electrode. Concerning Na battery, only intercalation in TiS2 and WO3 was considered.

Working on layered potassium and sodium layered oxides, only from the solid state chemistry point of view, I decided to study intercalation processes in the NaxCoO2 system because various structural types could be obtained by high temperature chemistry depending on the Na amount. This led to the first paper on the Na//NaxCoO2 battery. Simultaneously, J. Goodenough do the same in the homologous Li system (he made the good choice). Then my work was extended to the NaxMO2 (M = Ti, Mn, Ni, Nb) materials and to mix Co,Ni phases. Various systems were explored with Li and Na intercalation. This led, for example to the first intercalation in Nasicon phases.

At this time only alkali metals were used as negative electrode; therefore, the applications were limited. When Sony proposed in 1989 the first Li-ion Battery a fantastic market opened and most of the researches were then focused on materials with promising applications. In 1991, we proposed the LiNi1-xCoxO2 system which is used till now in most of the batteries for spatial applications. The Ni-rich phases, which are now very promising for EV, where intensively studied in my group till 2005, then followed by the lithium-rich system.

Recently, we revisited the Na layered phases with V and Mo. These ions with d2 and d3 configurations like to form M-M bonds via their t2g orbitals, therefore the study of the structural changes upon Na intercalation (deintercalation) was interesting.

In the perspective of the development of very large scale renewable energy systems the prevailing parameters are the lifetime, the price and the material availability. A general investigation was undertaken on Na layered oxides with several transition metal ions. The studies were focused on P2-type layered phases. One of the main interests of this structure is the existence of an ion conduction plane made of face sharing trigonal prims which exhibits a high ionic diffusivity thanks to the existence of a large bottleneck (oxygen rectangle) for sodium diffusion. This structure is able to accommodate a lot of transition metal cations, allowing the optimization of the properties by cationic substitution.

In all our studies we try to use a solid state chemist approach: structural and physical properties characterization in addition to the electrochemical characterization. The electrochemistry is a probe inside the material which is able to detect all changes (structural or electronic). The solid state chemistry is able to understand what is going on.

Several examples will be given in this general overview.
(Invited) Advanced Lithium Ion Batteries with Cobalt Free Cathode Materials
Authors: Axmann Peter , Mancini Marilena , Gabrielli Giulio , Balasubramanian Prasanth , Wohlfahrt-Mehrens Margret
Published: February 2020

Lithium ion batteries are widely used in many applications and are the most promising energy storage systems for future mobility. The development of cobalt free cathode materials with high capacity and high voltage can contribute significantly to further cost reduction and better safety compared to lithium ion batteries with Nickel rich layered oxides like NMC622 or NMC811 as cathode material.

We report the synthesis and characterization of a series of Co-free, Li-rich Li1+xNi0.5Mn1.5O4 (0<x<1) cathode materials obtained via a low-temperature synthesis method. These materials give high reversible capacities up to 250 mAh/g cycled between 2.4 and 4.9 V vs. Li/Li+, high rate capability and good cycling life. Th cycling stability can be further improved by optimizing morphology, particle size distribution and additional surface coating and proper selection of electrolyte.

Full cell data of these cathode materials in combination with graphite or silicon/carbon composites as anodes demonstrate 15 to 20% higher specific energy compared to reference cells using NCM622 as cathode material, excellent rate capability, better safety and good cycling life.
Negative Electrodes for Longer Life, High Energy Li-S Batteries
Authors: Ulissi Ulderico , Rikarte Jokin , Carboni Marco , Locke Jacob
Published: February 2020

As we approach the limits of lithium-ion batteries, new alternative chemistries are required[1]. Those that involve the sulfur conversion reaction at the positive electrode are among the most promising to move beyond Li-ion[2]. The conversion reaction of sulfur to form lithium sulfide is characterized by a high theoretical specific capacity of 1672mAh g-1, translating in a theoretical energy density of c.a. 2500 Wh kg-1, a value 2.5 times higher than that of commercial state-of-the-art Li-ion cells, using transition metal oxide based cathodes[3].

There are well-documented challenges associated with the traditional Li-S system which have been demonstrated to restrict the practical energy density and the cycle life[4]. Soluble polysulfides are generally formed, resulting in the shuttling mechanism, a major issue causing low coulombic efficiency, high self-discharge rates and negative electrode corrosion[4]. This reaction is also associated with large volume changes. This can lead to cell failure, due to the alteration of the cathode and anode structure and the favoured formation of lithium dendrites[5].

Strategies to enhance cycle life, while maximizing practical energy density, require a holistic approach. This includes optimization of the positive electrode (e.g., selection of conversion reaction catalyst, use of polysulfide adsorbents, binder selection); the negative electrode (e.g., lithium coating, functionalization and protection); the separator (e.g. functional barriers and polymeric membranes); the electrolyte (e.g. use of alternative solvents and salts, additives).

This work will focus on the recent negative electrode advances at OXIS Energy Ltd, the pioneer in the research and development of large-scale, high-energy, longer cycle life lithium-sulfur batteries.

[1] D. A. J. R. Ronald M. Dell, Lithium Batteries, John Wiley & Sons, Inc., Hoboken, NJ, USA, 2013.

[2] B. Scrosati, J. Hassoun, Y.-K. Sun, Energy Environ. Sci.
2011, 4, 3287.

[3] M. S. Whittingham, Proc. IEEE
2012, 100, 1518.

[4] A. Manthiram, Y. Fu, S. H. Chung, C. Zu, Y. S. Su, Chem. Rev.
2014, 114, 11751.

[5] X. Liu, J.-Q. Huang, Q. Zhang, L. Mai, Adv. Mater.
2017, 29, 1601759.
Titanosilicate Sitinakite Compound As a Low-Potential Anode for Sodium-Ion Battery
Authors: Liu Yao , Xia Yong-Yao
Published: February 2020

Sodium-ion batteries (SIBs) have been considered as a promising candidate for large-scale energy storage applications, because of the low cost of sodium element and a broad choice of cathode materials which do not contain the expensive raw materials. However, a lack of promising anode materials still hinders the development of SIBs technology. Herein, we for the first time report a one dimensional tunnel-structure titanosilicate sitinakite compound with an ideal formula of Na1.68H0.32Ti2O3SiO4·1.76H2O employed as a new type anode material in SIBs. This material can deliver a reversible capacity of 110 mAh g-1 at a current density of 20 mA g-1 and with an average working voltage of 0.4 V vs. Na+/Na. The structure changes of this material during discharge/charge processes were investigated by using in-situ laboratory X-ray diffraction. The results indicated that sodium insertion proceeds via a topotactic intercalation pathway. We also identified pre-dehydration as an effective avenue to further improve the capacity of Na1.68H0.32Ti2O3SiO4·1.76H2O anode (reversible capacity of 131 mAh g-1 at a current density of 20 mA g-1 after pre-dehydration process). In addition, cation Nb doped Na1.68H0.32Ti2O3SiO4·1.76H2O compounds have been synthesized and systematically investigated the electrochemical performances in SIBs.

Reference

[1] Liu, Y.; Xia, Y., Na1.68H0.32Ti2O3SiO4·1.76H2O as a Low-Potential Anode Material for Sodium-Ion Battery. ACS Applied Energy Materials
2018, doi:10.1021/acsaem.8b01412.
Exploring Cobalt-Based Lithiated Spinel Cathodes
Authors: Lee Eungje , Croy Jason R. , Thackeray Michael M.
Published: February 2020

Over recent years, our group has demonstrated that the incorporation of a spinel (S) component into ‘layered-layered’ (LL) composite electrode structures serves, as a stabilizing unit, to slow transition metal migration during electrochemical cycling.[1] However, unraveling the mechanism by which the S component operates in actual ‘layered-layered-spinel’ (LLS) materials is a challenging task because of the highly complex, inhomogeneous arrangements of the cations (typically Li, Mn, Ni, and Co) within multiple nano-domains. Moreover, relatively little is known about the structure and electrochemical properties of Co-based spinel materials, which were first reported in early 1990s[2,3], compared to Mn-based spinels. The lithiated spinel Li2Co2O4 is particularly attractive as a stabilizing agent in LLS composite electrodes for two reasons. First, cobalt has a lower propensity to migrate during electrochemical Co3+/4+ redox reactions and, second, lithium extraction from Li2−zCo2O4 (0 ≤ z ≤ 1), occurs at a potential (∼3.6 V) that is significantly higher than that of its lithiated manganese-oxide spinel analogue, Li2Mn2O4 (∼2.9 V). In this presentation, we will discuss the structure and electrochemical properties of substituted lithiated spinel materials that are easier to produce as a single phase, thereby eliminating the propensity for Li2Co2O4 samples to be contaminated by some layered LiCoO2.

References

[1] M.M. Thackeray, J.R. Croy, E. Lee, A. Gutierrez, M. He, J.S. Park, B.T. Yonemoto, B.R. Long, J.D. Blauwkamp, C.S. Johnson, Y. Shin, and W.I.F. David, “The quest for manganese-rich electrodes for lithium batteries: strategic design and electrochemical behavior,” Sustainable Energy & Fuels
2, 1375-1397, (2018).

[2] R.J. Gummow, M.M. Thackeray, W.I.F. David, S. Hull, “Structure and electrochemistry of lithium cobalt oxide synthesized at 400oC," Mater. Res. Bull.
27, 327-337, (1992).

[3] E. Lee, J. Blauwkamp, F.C. Castro, J. Wu, V.P. Dravid, P. Yan, C. Wang, S. Kim, C. Wolverton, R. Benedek, F. Dogan, J.S. Park, J.R. Croy, M.M. Thackeray, "Exploring Lithium-Cobalt-Nickel Oxide Spinel Electrodes for ≥3.5 V Li-Ion Cells," ACS Appl. Mater. Inter.
8, 27720-27729, (2016).
Electrothermochemical Behavior of External Short of Lithium Ion Batteries
Authors: Doh Chilhoon , Ha Yoon-Cheol , Eom Seung Wook
Published: February 2020

Yazami1 reports on the thermodynamics of lithium ion battery. The understanding on heat generation of battery during charge and discharge and on heat dissipation is very important to maintain within appropriate temperature range2-4. Especially, it is highly important in the case of the battery of large capacity.

Here, drastic discharge with external resistance was studied with experimental and computational approach applying evaluated parameters of entropy, internal resistance, specific heat and open circuit cell potential. The coulombic capacity of used cell was ca 100 Ah. A case of external short was presented as below figure.

Acknowledgment: This study was supported by the KERI R&D program of MSIP/NST (18-12-N0103-01) and 18-02-N0108-02.

References:

Kazunori Ozawa, Lithium Ion Rechargeable Batteries, Ch. 5, Wiley-VCH Verlag GmbH & Co. KGaA, 2009.

K. Maher, R. Yazami, Electrochimica Acta, 101 (2013) 71.

K. Jalkanen, T. Aho, K. Vuorilehto, Journal of Power Sources 243 (2013) 354.

D.H. Jeon, S.M. Baek, Energy Conversion and Management 52 (2011) 2973

Dong Hyup Jeon, Current Applied Physics 14 (2014) 196.

Figure 1
Supply Chain Management Models for Mobile Battery Energy Storage Systems
Authors: Zhang Xuewei
Published: February 2020

This work proposes a promising scenario of large-scale deployment of battery energy storage systems that attempts to address three important issues toward a sustainable energy landscape in the near future: (1) Suppressed grid integration of variable renewable generations such as wind; (2) Low profitability of battery energy storage systems due to limited applications; and (3) Conflicts between the current power infrastructure and the installation of charging stations to meet the growing needs of electrical transportation. To maximize the utilization of renewable energy while increasing the profitability of battery energy storage systems, a new concept has emerged from our previous work which envisions a transition from "Battery Farm" to "Battery Warehouse", i.e. the batteries can be mobilized instead of completely stationary. More specifically, we design a system in which electric trucks transport the batteries between battery warehouse and electric vehicle charging stations. This facilitates the planning and operation of electric vehicle charging station networks without constraints from the grid. In many areas in the United states (e.g. Texas) where there are abundant renewable energy sources and the road networks do not suffer from frequent congestion, this could be a viable solution. To further demonstrate its feasibility, in this work, we use the theoretical framework of supply chain management and investigate a three-layer supply network (battery warehouse, charging stations, electric vehicles). The objectives are two-folded: firstly, developing an integrated pricing method to include costs, risks, and consumer utilities; and secondly, determining the locations and sizes of charging stations to minimize costs in the logistics system. Using the city of Corpus Christi, Texas and the nearby Chapman Ranch wind farm as test case, we implement the design and simulate its performance based on the supply chain management models. The two main performance indexes are: reliability (supply can always meet demand) and profitability. While the former can be ensured through good planning and control, the latter remains an open problem. However, our preliminary results in this work, even if far from definitive due to various assumptions and uncertainties, would shed some light on this issue to help potential stakeholders make business decisions or policy recommendations.
(Invited) Multiscale Image-Based Control and Characterization of Lithium-Ion Batteries
Authors: Blanc Remi , Niklaus Matthieu , Lichau Daniel , Chirazi Ali , Barthelemy Patrick
Published: February 2020

Lithium-ion batteries (LIB) are today the main energy storage devices from portable electronics devices to electric vehicles. LIB have a high energy density, low self-discharge, and low memory effect allowing for large number of charging cycle without degrading storage capacity. Performance, cost and safety are the main factors driving research and different chemistry are investigated in order to achieve better performance at a lower cost and increase safety.

Research, development and quality control of LIB can benefit much from X-ray Computed Tomography (CT) and Focused-Ion Beam – Scanning Electron Microscopy (FIB-SEM).

MicroCT allows for complete non-destructive acquisition of a complete battery cell, allowing to control the production process and to monitor the changes occurring in the structure during multiple charging cycles. Different visualization techniques are proposed on a 7µm microCT acquisition of a Lithium Nickel Manganese Cobalt Oxide cell 18650 (NMC) which allow for a visual inspection of the internal structure of the cell, including techniques of unfolding to look at rolled electrodes and measurement such as electrode thickness, height, or length.

Macroscopic properties of a battery, including mechanical, thermal and electrical, find their origins at a nano-scale. Using FIB-SEM, high resolution images can be acquired which can reveal the structure of the electrodes or the separator. Besides the volume fraction or surface areas of the different phases, the connectivity of pores and/or particles, their surface of contacts, path tortuosity or constrictivity, permeability or molecular diffusivity, become accessible. We will present simulation results on permeability and tortuosity on this sample.

We will also present correlative experiment, performing first a microCT scan of a cathode foil sample on its aluminium collector, spotting sites of interest in it, and acquiring those volumes with FIB-SEM.
Catalyst-Free, High-Loading Silicon Nanowires Anodes for Lithium Ion Batteries
Authors: Schneier Dan , Menkin Svetlana , Harpak Nimrod , Davidi Guy , Mados Edna , Ardel Gilat , Patolsky Fernando , Golodnitsky Diana , Peled Emanuel
Published: February 2020

We report on the scalable synthesis and characterization of novel architecture three-dimensional high-capacity amorphous Silicon Nanowires (SiNWs)-based anodes, with less than a third of the thickness of common graphite anodes. The SiNWs were grown by a novel, catalyst-free chemical vapor deposition (CVD) process, on a commercial stainless steel (SS) mesh. By using our novel, low-cost CVD procedure we synthesized binder-free anodes with loadings of up to 5mgSi/cm2, that have shown stable cycle life for over 600 cycles and provided capacities of up to 6mAh/cm2, very low (<10%) irreversible capacity and good compatibility with commercial cathodes. With the use of two- and three-electrodes coin cells we focus on studying their electrochemical performance and degradation mechanisms. It was found that the observed capacity loss of the SiNWs-based anodes is mainly caused by the increase in the resistivity of the SEI layer, along with the steady rise of the charge/discharge overpotential detected on both the anode and the cathode. Our anodes have been coupled with commercial cathodes (LFP and NCA), and have the potential to increase the energy density of LIBs by over 40%. In order to prove the scalability of our anodes, they have been successfully incorporated in industrial-size cylindrical cells, proving their potential as a viable candidate for anodes of the next generation lithium ion batteries for portable electronics and electric vehicles. Most recently, these anodes have been successfully coated with solid polymer electrolytes and cycled in all-solid state cells as a proof of concept, paving the way for safer, more durable LIBs.
Strategies for Limiting Gas Evolution in Li-Ion Batteries Applied to the Energy Storage System
Authors: Daigle Jean-Christophe , Asakawa Yuichiro , Zaghib Karim
Published: February 2020

One of the promising approaches for limiting climate changes is to use alternatives and greener sources of energy (wind, solar, etc.). However, the production of electricity from these sources is fluctuant and needs a solution for storage thus, the advent of energy storage for wind power, solar plant, etc., requires a new generation of batteries in order to optimize the use of these alternative sources of energy. To do so, the development of a battery with a high rate of charging and discharging, a longer cycle life and safe is imperative.

Esstalion Technologies was a joint-venture between Hydro-Québec and Sony Corp. (Murata) for the development of energy storage systems. Our division (Battery Materials Research) was dedicated on the elaboration of new materials for enhancing the cycle life, the safety and the performances of the Li-ion batteries. We devoted our efforts to develop LFP-LTO batteries; this presentation will highlight our strategies to limit the gas evolution in a battery; two strategies will be presented, the use of an additive in the cell for limiting the degradation of the electrolyte and the protection of the surface of the active inorganic particles by a hydrophobic polymeric coating before the production of the electrode.

Formation of a solid-electrolyte-interface (SEI) during the operation of the battery is the most applicable for partially preventing degradation. Recently, we reported on the use of polymers as a protective layer; the thin film is in situ polymerized on the anode during cell operations or grafted on the surface of particles before manufacturing as electrodes. We demonstrated the efficient use of in situ Ring Opening Polymerization (ROP) of propylene carbonate for creating a protective film on the anode surface. By this method, we reduced gas evolution in the cell without increased of internal resistance. Moreover, two methods to graft polymers on particles (LTO) were applied with success for preventing degradation of LFP-LTO cells. Because battery environments are aggressive (HF formation, pH = 2), we developed a new robust method for grafting hydrophobic polymers on active particles (LTO) by Williamson Ether Synthesis, which is compatible with the manufacturing of electrodes, and prevents significant cell degradation over extensive cycling.

These methods are valuable for large production because it is inexpensive and easy to scale-up. They are able to limit the degradation of the battery by increasing the capacity retention and stabilizing the resistance of the electrode with the accelerated aging.
First Insights for the Investigation of the Electrical Contact Among the Particles of Lithium Ion Battery Cathode Materials
Authors: Kröger Till-Niklas , Wiemers-Meyer Simon , Winter Martin , Nowak Sascha
Published: February 2020

Mechanical degradation phenomena arising from the volume change during charging and discharging can severely affect the electrical contact among the particles within the composite cathode material. Furthermore, electrochemically induced particle disintegration at high currents (e.g. for LiNi1/3Mn1/3Co1/3O2 (NMC111)) is conceivable to have a major influence on the loss of electrochemical performance.

There is a variety of electrochemical monitoring and investigation techniques for the analysis of electrode materials (e.g. impedance spectroscopy, X-Ray Diffraction, Raman spectroscopy). However, there is no sensitive analytical method in the field of battery research for the investigation of particles and the integrity of the conductive network among them within the composite electrode material. Therefore, the development of novel analytical approaches for the investigation of particle contact and the resulting contribution on the capacity fading is mandatory. The focus of this work is the development of a method for particle analysis of lithium ion battery (LIB) cathode materials by means of inductively coupled plasma based techniques with optical emission spectroscopy (ICP-OES) and mass spectrometry (ICP-MS).

Presuming an intact conductive network among the particles of the active material, the state-of-charge (SOC) should be equal throughout the electrode. Because the SOC correlates to the degree of lithiation (DOL) of the particles, the assessment of electrical contact is accessible by determining the ratio of lithium and host element (e.g. nickel, cobalt, manganese).

For ICP-based techniques, the particle size distribution requires to be narrow and small-sized for the accurate element determination. Furthermore, due to potentially occurring Li+-H+ exchange reactions, the sample introduction of NMC cathode materials in aqueous media is not feasible[1]. Therefore, the size dependent separation is performed by the principle of air classification and the particulate sample is introduced by means of an argon flow to the plasma. The utilization of particle classification indicates the applicability for ICP-based particle analysis due to the facilitation of low particle number concentrations and narrow size distributions and the results for ICP-MS and -OES exhibit the fundamental functioning for the application in particle analysis.

[1] J. Li, R. Klöpsch, S. Nowak, M. Kunze, M. Winter, S. Passerini, J. Power Sources. 2011,
196
, 7687-7691.
Quenched Li0.6FePO4 As a Vehicle for Studying Phase Separation Kinetics in Li-Ion Battery Materials
Authors: Savignac Laurence , Schougaard Steen Brian
Published: February 2020

Olivine-type cathodes have asserted their ability to store energy efficiently in wide range of applications. Still, the phase transition process during charge and discharge raises questions regarding reactions rates, as the deintercallation/intercalation process via a phase transition mechanism is expected to affect ionic and electronic transport. In this study, the metastability of LixFePO4 solid solution is used to study the kinetics of the phase transition. Factors that affect the transformation of the metastable Li0.6FePO4 are reported, including preparation conditions and surface effects.

Crystal structure dynamics were examined via X-ray diffraction (XRD) while more localized changes were revealed by attenuated total reflectance infrared spectroscopy (ATR-IR). These two techniques corroborate to distinguish the metastable solid solution phase relative to phase separation which emerges over time. Specifically, Reitveld refinement was used with the aim of detecting lithium rich and lithium poor phases as a function of time, resulting in a phase transition kinetic profile. In addition, lithium content was confirmed by flame emission spectrometry (AES). Recent results show how the phase separation is affected by the Li-ion battery chemistry as well as physical conditions. Importantly, surface effects were identified as crucial aspects in the kinetics of phase separation. The developed techniques serve as an experimental tool towards understanding Li0.6FePO4 solid solution.
Alpha Power Transformed Inverse Lomax Distribution with Different Methods of Estimation and Applications
Authors: ZeinEldin Ramadan A. , Ahsan ul Haq Muhammad , Hashmi Sharqa , Elsehety Mahmoud
Published: February 2020

In this paper, a new three-parameter lifetime distribution, alpha power transformed inverse Lomax (APTIL) distribution, is proposed. The APTIL distribution is more flexible than inverse Lomax distribution. We derived some mathematical properties including moments, moment generating function, quantile function, mode, stress strength reliability, and order statistics. Characterization related to hazard rate function is also derived. The model parameters are estimated using eight estimation methods including maximum likelihood, least squares, weighted least squares, percentile, Cramer–von Mises, maximum product of spacing, Anderson–Darling, and right-tail Anderson–Darling. Numerical results are calculated to compare the performance of these estimation methods. Finally, we used three real-life datasets to show the flexibility of the APTIL distribution.
Study on the Power-Frequency Waves Distribution Characteristics for Half-Wavelength Transmission Lines Based on the Frequency-Length Factor
Authors: Chen Chang , Ma Xiaoyang , Yang Honggeng , Wang Weikang , Liu Yilu
Published: February 2020

To analyze the distribution characteristics of voltage and current along half-wavelength transmission lines (HWTLs) in the cases with or without short circuit in the steady state, the method based on the frequency-length factor (FLF) for lossy lines is proposed. Firstly, according to the pole condition of the FLF, the distribution characteristics of power-frequency waves along HWTLs are analyzed. Then, the comprehensive effects of the system parameters and fault resistance are explored, revealing the mechanism of the power-frequency resonance caused by nonmetallic short circuit. Meanwhile, unbalanced short-circuit fault is studied by exploiting additional impedance. The results show that the distribution of the maximum value of power-frequency resonance voltage is related to the system parameters but not to the fault impedance. When a HWTL is short circuited at 2640 km∼2930 km, the resonance voltage can reach to 21 p.u. In relation to symmetrical short circuit, the resonance voltage appears at 1469 km from the short-circuit point, while the position moves towards the short-circuit point with the increase of additional impedance in asymmetrical short-circuit conditions. Additionally, the model theoretically proves that the power-frequency overvoltage induced by short circuit does not appear on a line whose length is less than 1469 km. Finally, cases are studied on PSCAD to verify the accuracy of the model.
Hopf Bifurcation and Dynamic Analysis of an Improved Financial System with Two Delays
Authors: Kai G. , Zhang W. , Jin Z. , Wang C. Z.
Published: February 2020

The complex chaotic dynamics and multistability of financial system are some important problems in micro- and macroeconomic fields. In this paper, we study the influence of two-delay feedback on the nonlinear dynamics behavior of financial system, considering the linear stability of equilibrium point under the condition of single delay and two delays. The system undergoes Hopf bifurcation near the equilibrium point. The stability and bifurcation directions of Hopf bifurcation are studied by using the normal form method and central manifold theory. The theoretical results are verified by numerical simulation. Furthermore, one feature of the proposed financial chaotic system is that its multistability depends extremely on the memristor initial condition and the system parameters. It is shown that the nonlinear dynamics of financial chaotic system can be significantly changed by changing the values of time delays.
Risk Assessments of Water Inrush from Coal Seam Floor during Deep Mining Using a Data Fusion Approach Based on Grey System Theory
Authors: Guo Yaru , Dong Shuning , Hao Yonghong , Liu Zaibin , Yeh Tian-Chyi Jim , Wang Wenke , Gao Yaoquan , Li Pei , Zhang Ming
Published: February 2020

With the increase in depth of coal mining, the hydrogeological complexity largely increases and water inrush accidents happen more frequently. For the safety of coal mining, horizontal directional drilling and grouting techniques have been implemented to detect and plug the fractures and conduits that deliver high-pressure groundwater to coal mine. Taking the grouting engineering performed at Xingdong coal mine at 980 m below sea level as an example, we collected the data of grouting quantity, the loss of drilling fluid, gamma value, water temperature, average water absorption, distance between grouting loss points, water pressure on coal seam floor, and aquifuge thickness at 90 boreholes in the mine to conduct grey relational analysis, first. The analysis showed that the grouting quantity was highly correlated with all other factors. Subsequently, grey system evaluation was used to evaluate the risk of water inrush from the coal seam floor. The results of risk analysis illustrated that three water inrushes from Ordovician limestone occurred in mining face 2127, 2125, and 2222 in the study area were all located in the area with a risk score higher than 65. Through grouting, the identified cracks were effectively blocked and waterproof layers beneath the coal seam floors were constructed to reduce the threat of water inrush. By comparing the risk assessment results with three water inrush cases before grouting operation, we found that water inrush areas were consistent with the area of higher risk.
Ezetimibe: An Unusual Suspect in Angioedema
Authors: Lu Tiffany , Grewal Tarundeep
Published: February 2020

We describe a case of new onset angioedema likely due to Ezetimibe therapy in an elderly patient with a prior history of drug-induced bradykinin reactions who had been on the medication for multiple years. This is the second reported incidence of Ezetimibe-associated angioedema in literature. A 90-year-old African American female presented with angioedema of the face and oral mucosa with associated difficulty speaking developing hours after taking Ezetimibe 10 mg PO. She denied adding any new or unusual foods to her diet. A thorough clinical history determined Ezetimibe was the likely culprit. Ezetimibe was immediately discontinued. The swelling subsided after administration of methylprednisolone 125 mg, epinephrine 1 mg/mL, injection 0.3 mL, diphenhydramine 25 mg, and famotidine 20 mg BID within 48 hours. The patient’s C1 esterase inhibitor level was measured to be within normal limits. Food panel allergy testing showed very low or undetectable IgE levels in all categories. Based on the limited reports in literature and our current case, we conclude that there is a likely association of angioedema with Ezetimibe. The mechanism, however, is unknown since it is not related to bradykinin or mast cell-mediated activation. Clinicians should advise patients taking Ezetimibe to report any swelling of the lips, face, and tongue and to immediately discontinue its use if these signs are present.
A educomunicação na batalha contra as fake news
Authors: Costa Maria Cristina Castilho , Romanini Vinícius
Published: February 2020

Este artigo trabalha com dois conceitos fundamentais, a educomunicação e a desinformação, procurando mostrar que a manipulação de informações e a influência das tecnologias de comunicação sobre a opinião pública têm sido uma preocupação central dos filósofos e estudiosos da comunicação humana. Assim, analisando a desinformação como fenômeno da atualidade, são apresentadas as principais teorias das ciências da comunicação que trazem subsídios para estudá-lo – de perspectivas diferentes, mas complementares. A partir dessa abordagem, questões como democracia, ideologia e poder se tornam elementos aglutinadores dessas análises.
Apresentação
Authors: Fígaro Roseli , Baccega Maria Aparecida
Published: February 2020

Apresentação do número especial, 25 anos, retoma a apresentação publicada no número 1 de Comunicação & Educação, de autoria de Maria Aparecida Baccega.
Niche occupancy of two (congeneric) skinks in an islands environment
Authors: Civantos Emilio , Arribas Rosa , Martín Jose
Published: February 2020

Among the scincid lizards inhabiting the Mediterranean region, the Ocellated skink (Chalcides ocellatus) and the little-known and endangered Chafarinas’ skink (Chalcides parallelus) co-occur in sympatry at the Chafarinas Islands (NW Africa). Although both species are present in the archipelago, C. ocellatus is spread in the three islands, but C. parallelus is present only in one island. What factors influence this distribution, and whether these two species show evidence for syntopy is unknown. In this study, we investigated spatial niche occupancy at the level of microhabitat of both skinks at the Chafarinas Islands. We tested for microhabitat differences between islands and then, we tested the null hypothesis of no differences between microhabitat used by each of these skink species and a set of locations chosen at random from the general habitat. Results showed that the distribution and abundance of available microhabitats were different among islands, thus each island has different spatial niches that may be important in distinguishing the areas occupied by these skinks. Results also revealed that C. ocellatus did not use available microhabitats at random, but preferentially selected particular microhabitats. However, C. parallelus used microhabitats according to their availability, although it showed some aspects of habitat selection similar to C. ocellatus. Our results showed that the inclusion of detailed microhabitat descriptors could be useful for understanding patterns of niche occupancy by these skinks species. Furthermore, to our knowledge this is the first study documenting the spatial niche selection of C. parallelus and provides novel ecological information that may be of major importance to develop management strategies that will help to conserve this endangered species.
Species of the Maera-clade collected from Japan. Part 3: genera Maera Leach, 1814, Meximaera Barnard, 1969 and Orientomaera Ariyama, 2018 (addendum), with a key to Japanese species of the clade (Crustacea: Amphipoda: Maeridae)
Authors: ARIYAMA HIROYUKI
Published: February 2020

Two species of Maera Leach, 1814, a species of Meximaera Barnard, 1969 and a species of Orientomaera Ariyama, 2018 included in the Maera clade, are described from Japan. Maera loveni (Bruzelius, 1859) was collected from the Sea of Japan and can be distinguished from its congeners by the very large body size and the gnathopod 2 palm defined by a blunt tooth bearing a strong robust seta. Maera sagamiensis sp. nov. from Sagami Bay is characterized by the presence of small notches on the coxae 1–3. Meximaera mooreana (Myers, 1989) was collected from Wakayama Prefecture and has two distinct characters: the male gnathopod 2 with wide basis and the very long uropod 3. Morphological characters of the Japanese specimens resemble well those in the literature, but the mandibular palp article 1 is projected acutely. Orientomaera incisa sp. nov. was recently collected from Wakayama Prefecture and its gnathopods 2 in both sexes bear a distinctive incision on the palm. Keys to species of Meximaera in the world and Japanese species of the Maera-clade are provided. Fifteen species included in the Maera-clade occur in Japan.