bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding Morphology Evolution in Lithium Electrodeposition
Authors: Tewari Deepti , Liu Zhixiao , Mukherjee Partha P. 
Published: February 2020

Lithium-ion batteries are poised to play an important role in the push for electric vehicles. Electroplating and possible dendritic growth, however, have been a safety concern. Non-uniform electrodeposition and subsequent growth may cause short circuit. Apart from catastrophic failure, Li plating results in the battery performance decay as well. There is a need for a better understanding of the factors that are most critical in the nucleation and growth of Li electrodeposition and the morphology evolution thereof. The metal ion reaches the electrode surface where it is reduced. The metal atom can thereafter diffuse inside the bulk electrode or aggregate on the surface under some specific set of conditions and form a variety of structures on the electrode surface, like small islands, uniform film, mossy or filament like structure or dendrite (as schematically shown in Figure 1). Physicochemical determinants affecting electrodeposition include the adsorption energy of metal atom on electrode surface, diffusion barrier for metal atom in the bulk electrode compared to that on the electrode surface, the crystallographic nature of the electrode surface, the strength of cohesive metal-metal interaction. Beyond the nature of the electrode material, the operating temperature, current density and applied potential can also affect the electrodeposition rate, which consequently control the morphology evolution. In this study, a mesoscale interfacial modeling and analysis is presented in order to investigate the lithium electrodeposition regimes and morphology evolution.

Figure 1
Solid-Electrolyte Interphase Reinforcement Strategy through Introducing Covalently Anchored Multi-Functional Components for Li-Alloy Anodes
Authors: Gao Yue , Wang Donghai 
Published: February 2020

Li-alloy based anode materials are very promising for breaking current energy limits of lithium-ion battery technologies. At present, their practical applications are mainly hindered by the solid-electrolyte interphase (SEI) stability issue. SEIs of Li-alloy anode materials exhibit insufficient surface passivation to prevent electrolyte penetration and suffer from cracking and peeling-off issues due to their poor tolerance to volume changes, consuming additional electrolyte and material for SEI repair.
Here we propose a chemical SEI reinforcement strategy via introducing multiple functional components as SEI components, which have strong interactions with Li-alloy material surface and effectively improve the SEI stability, including its tolerance to volume changes and surface passivation during cycling. Using a modular synthetic approach, we realized a one-step fabrication of diverse components with designed structure and anchoring amount, allowing the facile construction and optimization of the SEI. Si nanoparticle (SiNP) materials were used as the platform for demonstrating this concept. After screening and optimizing the SEI structure using various pre-anchored components, one chemically reinforced SEI (CR-SEI), reinforced by a combination of two functional components with moderate anchoring amount shows significantly improved stability compared to the SEI derived from electrolyte with FEC additives. During cycling, the CR-SEI presents unique and stable chemical composition, resulted form the addtion of pre-designed functional components, which differs from the composition of conventioal SEI. Meanwhile, the CR-SEI also maintains good and durable morphology during cycling. After many cycles, only very limited “SEI accumulation” was observed in the TEM images of SiNP with CR-SEI and the CR-SEI remains thin and uniform. This is in contrast with the poor stability of conventional SEI. Large amount of SEI accumulation and SiNPs decrease in size were observed. Finally, owing to the improved SEI stability, SiNP electrode with CR-SEI presents significantly increased electrochemical performance, including increased 1st cycle Coulombic efficiency (CE), improved cycling CE and capacity retention, and limited increase in electrochemical impedance. Particularly, the SiNP electrode with CR-SEI present much better cycle life in the full-cell system than one containing electrolyte additive improved SEI. Moreover, this strategy has also been applied to GeNP SEI reinforcement with dramatic enhancement of the SEI stability, suggesting its viability for other Li-alloy materials. Owing to the facility and modularity of the synthetic approach, we are also able to further examine more functional components potentially suitable for SEI reinforcement.
Thermodynamic Investigation of Selected Compositions in the LiNiO2-LiMnO2-LiCoO2 System As Lithium Ion Battery Cathode Materials
Authors: Masoumi Maryam , Cupid Damian Marlon , Seifert Hans Jürgen 
Published: February 2020

The choice of cathode material is critical for determining the performance and safety of lithium ion batteries. Therefore, the development and optimization of new chemistries for cathodes of lithium ion cells is of major importance. Layered structured lithium mixed transition metal oxides with the general formula of LiNixMnyCozO2 (x + y + z = 1) and an α-NaFeO2-type layered structure (space group ) are attractive intercalation type cathode materials which overcome the limitations of LiCoO2, the most commonly used cathode for lithium ion batteries in portable applications. These NMC materials not only are isostructural to LiCoO2, but also offer comparatively higher reversible capacity, lower cost, and improved thermal stability, which are important characteristics for large scale applications.
Although the structural characteristics and electrochemical behavior of many promising compositions in the NMC system have been investigated to some extent, there are very few studies devoted to the thermodynamic properties of this class of materials. The enthalpies of formation of LiNi1−xCoxO2 compounds were determined by Wang and Navrotsky [1] using high temperature oxide solution calorimetry and the enthalpy of formation of LiNi1/3Mn1/3Co1/3O2 and its chemically delithiated phases were measured by Idemoto and Matsui [2] using acid solution calorimetry. In the present work, with the aim of investigating the effect of cation substitution on thermodynamic stability of NMC materials, the standard enthalpies of formation of two different series of sol-gel made NMC samples, namely LiNixMnxCo1-2xO2 (0 ≤ x ≤ 0.5) and LiNi0.8-yMnyCo0.2O2 (0 ≤ y ≤ 0.4), are determined by high-temperature oxide-melt drop solution calorimetry. The compositions are selected to include the technologically relevant NMC111, NMC442, NMC532 and NMC622 compounds.
It is shown that LiNixMnyCozO2 with layered structure is a nearly ideal solid solution of LiCoO2, LiNiO2 and LiNi0.5Mn05O2. Our calorimetry results show that the standard enthalpies of formation of the compounds from the elements vary almost linearly with composition in the respective area. Furthermore, based on our experimental heat of formation data and available low temperature heat capacity data for LiCoO2, LiNiO2 and LiNi0.5Mn05O2, a model for the variation of the Gibb’s free energy of formation and equilibrium potentials of the NMCs with composition at room temperature is presented. In addition, key electrochemical tests were performed to establish a relationship between the thermodynamic properties and electrochemical performance of the cathode materials. This work should help clarify the structure–property relationships in these compounds.

M.Wang, & A. Navrotsky, Solid State Ionics 166 (2004), 167-173.

Y.Idemoto & T. Matsui, Solid State Ionics 179 (2008), 625-635.
Biofilm Formation Behaviors on Graphene By E. coli and S. epidermidis
Authors: Kanematsu Hideyuki , Hirai Nobumitsu , Ogawa Akiko , Kogo Takeshi , Kuroda Daisuke , Utsumi Yuichi , Yamaguchi Akinobu , Ikegai Hajime , Mizunoe Yoshimitsu 
Published: February 2020

Biomaterials should have some required performances such as mechanical properties and biocompatibility. From the viewpoint, they have been investigated so far. However, an important factor has been missing in some cases. That is the infection resistance. And the final one is related closely to the biofilm and its control. In this experiment, we focus on graphene, an advanced material. The graphene has many high performances and biocompatibility. From the viewpoint, it may get a chance to be applied to biomaterials. However, our prelimnary experiments showed that graphene has its high sensitivity to resident microbiota and tended to form biofilms easily. Since resident microbiota form complicated flora composed of plural bacteria, it is very hard to tell which bacterium formed biofilm mainly. However, it would be very important to investigate the biofilm formation capability by a certain bacterium, when we come to think about the applicability to biomaterials. In this experiment, we chose E.coli as gram negative bacterium and S.epdermidis as gram positive one, since both cause infections and chronic diseases in our human bodies very often. Graphene was prepared by CVD (Cemical Vapor Deposition) and mechanical methods (tape-detachment process). The specimens were measured and the formation of graphene was confirmed by a Laser Raman Spectroscopy. The specimen was set in spme kinds of laboratory biofilm reactors (LBRs) which we have developed in our loboratory. LBRs were filled with liquid cultures including target bacteira. The test continued in a couple of days at a certain temperature (25 degrees Celsius for E.coli and 37 degrees Celsius for S.epidermidis.) After the immersion test in those LBRs, biofilms on graphene samples were observed and measured by Raman Spectroscopy, staing by crystal violets and optical microscopic observations. The results were compared, analyzed in various cases and the applicability of the advanced material to biomaterials and human bodies was discussed.
(Keynote) Transition Metal Sulfides As Intercalation Cathode Materials for Rechargeable Aluminum Batteries
Authors: Geng Linxiao , Guo Juchen 
Published: February 2020

Rechargeable aluminum (Al) batteries are promising technologies for large scale energy storage applications. One of the main challenges hindering the development of rechargeable aluminum batteries is the lacking of understanding of cathode materials. In this study, we investigate a number of transition metal sulfides as the intercalation-type cathode materials for rechargeable Al batteries. Our selection of metal sulfides instead of oxides as Al-ion cathode materials is crucial: Due to the strong coulombic effect, the energy barrier for multivalent ion transport in the oxide crystal structure is very high. Thus, a more polarizable (softer) anionic framework is needed for facile Al-ion intercalation-extraction. The sulfide anion is more polarizable than the oxide anion due to the larger size, making transition metal sulfides promising candidates as Al-ion cathode materials. We hereby demonstrate Chevrel phase molybdenum sulfide (Mo6S8) as the intercalation-type cathode material with aluminum chloride/1-butyl-3-methyimidazolium chloride (AlCl3-[BmIm]Cl) ionic liquid as the electrolyte. Electrochemical characterizations including cyclic voltammetry and galvanostatic charge-discharge demonstrate unambiguous Al intercalation-extraction in the Mo6S8. The X-ray diffraction analysis further indicates the crystal structure change of Mo6S8 after Al intercalation. In addition, we report the synthesis and electrochemical properties of layered TiS2 and cubic Ti2S4 as intercalation-type cathode materials for rechargeable aluminum battery at both room temperature and 50 °C. We further confirmed the aluminum intercalation in the TiS2 and Ti2S4 crystal structure using combined electrochemical analysis and ex-situ XRD. The proposed titanium sulfide cathode materials showed decent reversible capacity and a higher working potential than Mo6S8. Furthermore, our study suggests the low Al ion diffusivity in the titanium sulfide framework induced by strong coulombic intercalation is the key obstacle for fast discharge-charge. This finding could provide guideline for design and synthesis of future titanium sulfides electrode materials.
Rapid Detection of Toxic Heavy Metals with Boron-Doped Diamond Sensors
Authors: Rusinek Cory Allen , Becker Michael F , Ensch Mary , Rechenberg Robert , Hardy Aaron , Wehring Bettina , Schuelke Thomas 
Published: February 2020

Toxic heavy metals such as lead (Pb), cadmium (Cd), and mercury (Hg) cause serious health complications and ingestion of these toxins through contaminated drinking water, even at trace levels, has become a prominent issue. Chronic exposure to toxic metals such as Pb, Cd, and Hg is carcinogenic while causing other problems like kidney failure, severe neurotoxicity, and IQ loss. These problems are only magnified in children as several stages of bodily development can be severely hindered. Electroanalytical methods are an attractive technique for trace detection of heavy metals due to low cost of experimental tools, low limits of detection, multi-element analysis capability, and the possibility to package them into sensing devices. Specifically, boron-doped diamond (BDD) is a rugged, yet sensitive electrode material with significant potential in electrochemical sensing. Using square-wave stripping voltammetry (SWSV), we have developed BDD micro-electrode arrays (MEAs) as well as macro-electrode disks, achieving detection limits as low as 200 parts-per-trillion (ppt) for Pb with a deposition time of just 2 minutes. This is nearly 100x below the 15 ppb maximum contaminant level (MCL) in drinking water set by the Environmental Protection Agency (EPA). MEAs of various diameter and spacing were investigated to find the optimum geometry for both single and multi-element detection of Pb, Cd, Hg, Cu and Mn where results were compared with those obtained at various macro-electrode sizes. Additionally, pen-like sensors incorporating the optimized BDD working electrode, a BDD reference electrode, and BDD counter electrode were constructed and used for the detection of the aforementioned metal ions. Long-term stability of the BDD quasi-reference electrode was investigated in detail. The applicability of all electrode constructions for the detection of metal ions in drinking and environmental water samples were studied for rapid detection at home or in the field.

Figure 1
Electrochemical Detection of Sulfanilamide at MWCNT Coated Conducting Polymer Modified Electrode
Authors: Khan Shirinaz I , Chillawar Rakesh , Digal Pradesh , Motghare Ramani V 
Published: February 2020

Oxidation of sulfanilamide (SN) at the Glassy Carbon Electrode (GCE) modified with a thin layer of electropolymerized Eriochrome Black-T (EBT) and multi walled carbon nanotubes (MWCNT) was investigated voltammetrically. The performance of layer by layer modified composite electrode was compared with bare GCE, p(EBT)/GCE, and MWCNT/GCE using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). An enhanced current response and lower peak potential were observed for SN oxidation at the layered composite electrode compared to rest of the electrodes. Hence, it was employed for analytical determination of SN after optimization of experimental parameters. Under optimized condition, the oxidation peak current increased linearly with concentration of SN over the range of 2 x 10-8 to 5 x 10-6 M. The limit of detection was calculated to be 1.2 x 10-8M. The electrode showed good selectivity, repeatability and reproducibility. It was also successfully applied for the determination of SN present in spiked human serum and ground water samples.

Keywords Sulfanilamide, MWCNT, p(EBT), composite electrode, EIS.

Figure 1
Solvothermal Preparation of Microspherical Flowerlike Ni(OH)2/Graphene Oxide Electrode for Electrochemical Capacitor Application
Authors: Khaleed Abubakar Abubakar , Bello Abdulhakeem , Dangbegnon Julien Koudio , Olaniyan Okikiola , Mwakikunga Bonex W. , Manyala Ncholu 
Published: February 2020

The growing need for energy coupled with the rise in global warming and air pollution due to the burning and consumption of fossil fuels has led to an increase in alternative energy sources to meet the exponential rise in energy. Electrochemical capacitors also known as supercapacitors have attracted great attention in electrochemical energy storage application resulting from their outstanding work rate, excellent cycle life and moderate energy density. In general, they are classified into two based on the mechanism in which the store charges. Electrochemical double-layer capacitors (EDLCs) that store energy based on ion adsorption, and pseudocapacitors which store energy by the fast surface redox process. Composite of spherical Ni(OH)2/GO was synthesized via a surfactant free solvothermal technique and tested as electrodes for electrochemical capacitors. Structural and morphological analysis confirmed that incorporation of GO into Ni(OH)2 does not change the crystal structure of the pure hexagonal α-Ni(OH)2. Electrodes fabricated from the composite demonstrates a superior electrochemical performance by exhibiting a specific capacity of ∼ 420 mA h g-1 at 10 A g-1, with a corresponding rate capability of 78% when compared to that of pure Ni(OH)2, GO, and Mix-Ni(OH)2/GO. The stability study of the Ni(OH)2/GO composite exhibits a good capacity retention of ∼ 96% at a current density of 10 A g-1 after 3000 charge-discharge cycles.

Figure 1
Reduction in Diameters of Copper Nanowires Due to Low Energy Hydrogen Ions Beam Irradiation-Induced Sputtering Phenomenon
Authors: Honey Shehla , Morgan Madhuku , Ahmad Ishaq , Maaza Malik , Naseem Shahzad 
Published: February 2020

Copper nanowires (Cu-NWs) are leading contenders to replace indium tin oxides (ITOs) based traditional transparent conducting electrodes from the market due to their high mechanical flexibility and low-cost. In this work, Kilo-electron-volt (KeV) hydrogen (H+) ions beam irradiation-induced reduction in diameters of Cu-NWs is examined through transmission electron microscope (TEM) and scanning electron microscope (SEM). The reduction in diameters of Cu-NWs is found to occur via H+ ions beam irradiation-induced collision cascade of atomic displacements mechanism lead to continual reorganizing Cu atoms in individual Cu-NWs lattices. Formation of defect clusters or loss of crystal structure is not found in x-ray diffraction (XRD) patterns due to H+ ions beam irradiation. These experimental findings may potentially be applied to enhance spaces between NWs in complex Cu-NWs meshes for application as transparent conducting electrodes. Moreover, this study has also significance in exploring the possibility for application of Cu-NWs meshes based optoelectronic devices in harsh environment containing plenty of H+ ions such as for use in spacecrafts for upper space missions.
Effects of Oxide Composition of Amorphous RuO2-Ta2O5 Catalyst on Electrochemical Sensing to Hydrogen Carbonate Ion
Authors: Iketani Chinami , Honda Ai , Morimitsu Masatsugu 
Published: February 2020

Hydrogen phosphate (HPO4
2-) and hydrogen carbonate (HCO3
-) ions are major in environmental water and blood, and the quantification is normally carried out by molybdenum blue method for HPO4
2- and by titration method or the gas analysis of blood for HCO3
-, while no quantitative method by electrochemical sensing has been developed. We have recently reported that these ions can be detected and quantified by electrochemical oxidation with the novel catalyst, amorphous RuO2-Ta2O5 mixed oxide, prepared by thermal decomposition [1,2]. For practical uses of the amorphous oxide catalyst for the detecting electrode, it is important to know the effects of the oxide composition of the catalyst to the sensitivity and selectivity to HCO3
- and HPO4
2-. In this paper, we studied the sensing properties to these ions with RuO2-Ta2O5 catalysts prepared at different compositions.
RuO2-Ta2O5 catalysts were prepared by thermal decomposition of a precursor solution containing Ru (III) and Ta (V) painted on a titanium disk. The Ru:Ta mole ratio was 20:80, 30:70, 50:50, or 80:20, and thermal decomposition was carried out at 260 oC. The characterization of the oxide coating was done with XRD, SEM, and EDX. Electrochemical measurements were performed with a conventional three-electrode cell with KCl-saturated Ag/AgCl reference electrode and 50 mmol/L KCl solutions with or without various concentrations of KHCO3 or Na2HPO4. Cyclic voltammetry was carried out to analyze the oxidation reactions of these ions, and chronoamperometry was also used to measure the oxidation current at various concentrations of HCO3
- or HPO4
2-. All measurements were done at 30 oC.
XRD and SEM measurements revealed that the obtained RuO2-Ta2O5 catalysts were amorphous, irrespective of the oxide composition. The cyclic voltammograms presented an oxidation wave for each of HCO3
- and HPO4
2-, and the oxidation current density increased with increasing concentration of each ion, indicating that HCO3
- and HPO4
2- are oxidized on the catalyst prior to oxygen evolution. The onset potential and peak potential of the oxidation of HCO3
- or HPO4
2- shifted negatively with increasing Ru mole ratio of the catalyst, in which the onset potential of HCO3
- was 0.1 V nobler than that of HPO4
2-. The oxidation current at different ion concentrations measured by chronoamperometry revealed that the concentration of HCO3
- or HPO4
2- was linear to the oxidation current density for each ion at all oxide compositions from Ru = 20 mol% to 80 mol%. Among them, the sensitivity for HCO3
- or HPO4
2- was highest at Ru = 50 mol%. More detailed results will be shown in this paper.

This work was supported by “Kyoto Area Super Cluster Program” of Japan Science and Technology Agency (JST).

References
[1] T. Tsukuma and M. Morimitsu, The 66th Annual Meeting of International Society of Electrochemistry, Abs# s01-014, Taipei (2015).
[2] A. Honda and M. Morimitsu, PRiME2016, Abs# 3785, Hawaii (2016).