bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lithium Halides As Redox Mediators in Lithium Oxygen Battery
Authors: Kwak Won-Jin , Hirshberg Daniel , Sharon Daniel , Afri Michal , Frimer Aryeh A , Aurbach Doron , Sun Yang-Kook 
Published: February 2020

In case of soluble electrolyte catalysts for Li-O2 batteries as a redox mediator, they were utilized to facilitate the exchange of electron and lithium ion, which can help formation and decomposition of discharge product. Although further researches are needed for finding proper catalysts, there is a promising approach fortunately, using lithium halides as a redox mediator in Li-O2 batteries.
Related researches have been progressed vigorously. Previous paper reported in our group demonstrated the reaction mechanism and effect of the lithium iodide (LiI) in Li-O2 battery.1 Lim et al. exhibited the superior performance of Li-O2 battery using LiI additive.2 Recently, Liu et al. developed this concept and exhibited Li-O2 battery having better performance with LiOH as a discharge product by adapting more advanced electrodes.3 However, further research with LiI is necessary for clear comprehension because there is no accurate elucidation on the reaction mechanism which can be activated gradationally in Li-O2 battery system yet.
Therefore, here in, we has progressed comparing and contrasting researches using LiI and lithium bromide (LiBr) for clearly understanding the role of lithium halide materials in Li-O2 battery system. As a redox mediator, LiBr catalyzes the reversible formation and decomposition of lithium peroxide (Li2O2), but hygroscopic LiI generated the side reaction making lithium hydroxide (LiOH) as a byproduct. Especially, when Li-O2 batteries are operated with LiBr and LiI until enough amount of capacities for practical using, LiOH made by LiI included electrolyte couldn’t be reversible compared to Li2O2 made by LiBr included electrolyte. Therefore, in our research, LiBr is much reliable redox mediator to operate the Li-O2 battery system.

References

Kwak, W.-J. et al.
J. Mater. Chem. A
3, 8855–8864 (2015).

Lim, H. et al.
Angew. Chem. Int. Ed. Engl.
53, 3926–31 (2014)

T. Liu. et al.
Science, 350, 6260, 530-533 (2015).
Printable Hecl Electrode Materials for Disposable Bioaffinity Assay Cartridges
Authors: Kulmala Sakari , Salminen Kalle , Kuosmanen Päivi 
Published: February 2020

We have demonstrated earlier that hot electrons can be injected into aqueous electrolyte solution from thin insulating film coated cathodes [1, 2]. Insulating film have typically been fabricated from an insulator material with a band gap of ca. 5 eV or preferably higher, with the Fermi level of the insulator somewhere in the mid band gap region. The hot electrons are emitted to aqueous electrolyte solution by direct field-assisted tunneling at these devices [2, 3]. After injection into the conduction band of water the hot electrons are thermalized and solvated to form hydrated electrons which finally act as reducing mediators in the Hot Electron-induced Electrochemiluminescence (HECL) systems. HECL is utilized mainly in immunoanalysis and in DNA-probe assays in which electrochemiluminescent labels are utilized [ 2 - 5 ]. Best labels are certain aromatic lanthanide chelates which allow sensitive time-resolved HECL detection of the labels [3, 6].
Silicon electrodes or silicon chips on which the working electrode/electrodes and counter electrode have been integrated have been shown to be excellent functional components of disposable assay cartridges [5,7]. Recently, we have been able to develop printable HECL electrode materials that show almost equal performance and are based on conductor particles embedded in polystyrene or in some other organic insulating materials.

References

[1] S. Kulmala, A. Kulmala, T. Ala-Kleme, J. Pihlaja, Primary cathodic steps of electrogenerated chemiluminescence of lanthanide(III) chelates at oxide-covered aluminum electrodes in aqueous solution, Anal. Chim. Acta. 367 (1998) 17–31.
[2] S. Kulmala, H. Joela, T. Ala-Kleme A. Kulmala, Hot electron injection into aqueous electrolyte solution from thin insulating film-coated electrodes, J. Radioanal and Nucl. Chem. 232 (1998) 91-95.
[3] J. Suomi, S. Kulmala, Hot Electron-Induced Electrogenerated Chemiluminescence, in: Rev. Fluoresc. 2009, 2011: pp. 47–73.
[4] T. Ala-Kleme, P. Makinen, T. Ylinen, L. Vare, S. Kulmala, P. Ihalainen, Rapid electrochemiluminoimmunoassay of human C-reactive protein at planar disposable oxide-coated silicon electrodes, Anal. Chem. 78 (2006) 82–88.
[5] T. Ylinen-Hinkka, a. J. Niskanen, S. Franssila, S. Kulmala, Immunoassay of C-reactive protein by hot electron induced electrochemiluminescence using integrated electrodes with hydrophobic sample confinement, Anal. Chim. Acta. 702 (2011) 45–49.
[6] S. Kulmala, T. Ala-Kleme, J. Suomi, Electrochemiluminescence of Lanthanides, in: Springer Series, Lanthan. Lumin., 2011: pp. 343–360.
[7] A.J. Niskanen, T. Ylinen-Hinkka, M. Pusa, S. Kulmala, S. Franssila, Integrated microelectrode hot electron electrochemiluminescent sensor for microfluidic applications, Sens. 152 (2011) 56–62.
Dual Sensing By Simple Heteroditopic Salt Receptors Containing an Anthraquinone Unit
Authors: Romański Jan , Karbarz Marcin 
Published: February 2020

We synthesized simple ion pair receptors consisting of a crown ether cation binding site and an anthraquinone supported thiourea anion binding domain and studied their anion, cation and salt binding properties using spectroscopic, spectrophotometric and electrochemical measurements in acetonitrille solution. Apart from carboxylate anions, which cause deprotonation all the anions tested were found to associate with receptors more strongly in the presence of sodium cations, whereas in the presence of potassium or ammonium cation the anion binding strength was greatly diminished. A homotopic anion receptor lacking a crown ether unit, was unable to bind sodium salt more strongly than tetrabutylammonium salts. Solution and solid state X-ray measurements revealed that strong sodium coordination with the cation binding domain is responsible for the salt binding enhancement. Electrochemical measurements showed that the addition of anions to the ditopic ion pair receptors pretreated with sodium cations resulted in greater changes in reduction potentials compared to the addition of anions to receptors in the absence of Na+.
Karbarz, M.; Romanski, J. Inorg. Chem.
2016, 55, 3616-3623.

Figure 1
Real-Time Monitoring of Bacterial Metabolites By Scanning Electrochemical Microscopy (SECM)
Authors: Joshi Vrushali S , Kreth Jens , Koley Dipankar 
Published: February 2020

Scanning Electrochemical Microscopy (SECM) is used to study the local chemical environment above live bacterial biofilms such as S. gordonii (Sg), S. mutans (Sm) etc. In this study, we report the development of a Pt decorated carbon nanotubes (CNTs) based dual SECM probe to detect low micro-molar range hydrogen peroxide (H2O2) produced by the live bacterial biofilm. This sensor showed sensitivity 2.2 ± 5 mA cm-2 mM-1 with low detection limit of 0.5 µM. Our results indicate that the Sg produced 65-70 μM H2O2 within 30 min in presence of 1 mM glucose in artificial saliva solution (pH 7.2) at 37°C. In addition, we have also developed a unique solid state carbon based potentiometric pH sensor and used as a SECM probe to map the pH change at high spatial resolution above the Sg biofilm. The sensor showed Nernstian response with slope of 58±4 and very fast response time of 5s. The pH mapping above the biofilm showed that pH above the biofilm dropped by one pH unit within 30 min only in 6 pH artificial saliva with 30 mM sucrose at 37°C. Recent developments about the real-time metabolic exchange between two bacterial species (Sg and Sm) in terms of peroxide and pH will be presented in the conference.

Figure 1
Ion Selective Microelectrodes and Scanning Electrochemical Microscopy to Study Dental Materials
Authors: Ummadi Jyothir Ganesh , Downs Corey , Koley Dipankar 
Published: February 2020

Solid-state ion-selective microelectrodes have an inherent advantage of having very fast response time and are used as probes for scanning electrochemical microscope (SECM). New dual function calcium ion selective microelectrode (Ca2+-ISME) and pH-ISME were developed and used as a SECM probes in this study to quantitatively map the chemical microenvironment produced by, bioactive glass (BAG). The carbon powder based Ca2+-ISME and the ployaniline deposited pH-ISME showed broad linear response range with Nernstian slopes. The selectivity coefficients of this Ca2+-ISME were found to be log KCa
2+
,A = -5.5, -6.7, and -6.1 for Mg2+, Na+, and K+, respectively. The Ca2+-ISME had a tip diameter of 25 µm and the inclusion of carbon powder made it redox sensitive. The amperometric function of the sensor was used to fix the tip-substrate distance by using approach curve technique with the SECM. The SECM experiments with the Ca2+-ISME showed that the BAG releases calcium ions in acidic conditions and neutralize the pH in the process. This was an important finding because there was no previous characterization of the 3D chemical environment at the surface of the BAG. The sensors were also used to characterize the dental materials with BAG incorporated into the resin. Such studies can be helpful to characterize novel dental materials that can be commercialized.

Figure 1
Magnetolastic Smart Tags Using Electroformed Cobalt Iron Boron
Authors: Langlois Eric Donald , Pillars Jamin Ryan , Monson Todd , Arrington Christian L. , Finnegan Patrick , Thorpe Adam , St. John Christopher R. 
Published: February 2020

Microfabricated magnetoelastic resonators forming the basis for a new, passive, wireless tagging technology platform have been developed. These magnetoelastic tags operate on the principle of Joule magnetostriction (i.e., a large change in material shape induced by an applied AC magnetic field) to produce magnetic signals and are an alternative technology to existing inductive RF tags. Lithographically patterned and electrochemically deposited (ECD) cobalt iron boron (CoFeB) alloy films are used to create the longitudinal mode magnetoelastic resonators. Due to the greater thickness and low-stress nature of electrodeposited films, these resonators can be released like other MEMS devices via a sacrificial layer to form free-standing structures. This batch fabrication technique also allows for multiple resonators of varying lengths and magnetic bias angles resulting in a multi-frequency signal that becomes the tag identity. Hysteresis curves to measure fundamental material magnetic properties that affect tag performance such as magnetic saturation, coercivity, and susceptibility were measured. Process flows for microfabricating resonators along with resonator design, modeling and characterization results will be presented. Future design concepts for tags with environmental sensing functions using this novel material set will be briefly discussed.
Yb,Er-Doped CeO2 Nanotubes for Photoconversion-Ehanced Dye-Sensitized Solar Cells
Authors: Diao Guowang , Zhao Rongfang 
Published: February 2020

Abstract: CeO2 doped with trivalent lanthanide ions(Ln3+) that possess intra 4f electronic transitions is a research focus owing to their fascinating optical properties and their significant application in optoelectronic devices[1].The dye-sensitized solar cells(DSSCs) as a promising third generation photovoltaic device have received a great deal of attention since its introduction in 1991 due to its low cost, easy production, and relatively high efficiency. It has recently exhibited an efficiency of 12.3%[2]. Cognitional DSSCs photoanode are comprised of a mesoporous network TiO2 nanoparticles which N719-dye molecules are absorded for light harvesting. We aimed to structure a new type complex photoanode with Yb,Er-doped CeO2 nanotubes(CeO2:Yb,Er NTs). Yb,Er-doped CeO2 nanotubes, synthesized using Ag nanowires as a hard template(as shown in Fig. A and B), were investigated to determine theirs photovoltaic properties in an effort to enhance the power conversion efficiency of dye-sensitized solar cells(DSSCs). Compare with pristine TiO2 photoanode, the DSSCs based CeO2:Yb,Er nanotubes exhibited a power conversion efficiency(η) of 8.67%, an increase of 34%, and incident photo-to-electric conversion efficiency(IPCE) of 92.96%, an increase of 48.83%,as can be seen from Fig. C and D. Energy band matching is formed at the interface of TiO2 layers and CeO2:Yb,Er nanotubes, thereby leading to decrease of electron-hole recombination[3].

References

Z. L. Wang, G. R. Li, Y. N. Ou, Z. P. Feng, D. L. Qu and Y. X. Tong, J. Phys. Chem. C, 2011, 115, 351-356.

A. Y. Pang, X. Sun, H. C. Ruan, Y. F. Li, S. Y. Dai and M. D. Wei, Nano Energy, 2014, 5, 82-90.

J. Tian, Y. H. Sang, Z. H. Zhao, W. J. Zhou, D. Z. Wang, X. L. Kang, H. Liu, J. Y. Wang, S. W. Chen, H. Q. Cai and H. Huang, Small, 2013, 9, 3864-3872.

Acknowledgement

This work was financially supported by the National Natural Science Foundation of China (Grant 21273195).
Degradation Phenomenon of Ni-YSZ Anode Support Cells Under Various Operating Conditions
Authors: Park Jun-Young , Kim Youdong , Saqib Muhammad 
Published: February 2020

Solid oxide fuel cells (SOFCs) is an electrochemical device which can directly convert chemical energy to electrical energy. They have many advantages including the high efficiency and multi-fuel flexibility. [1,2] Although high temperature-SOFCs have advantages in terms of performances high production cost and the limited durability are one of issues for making commercialization of SOFCs. Generally, SOFCs are required over 40,000 h life-time to enter into the real markets. [3,4] Furthermore, SOFCs should produce electrical power stably under a variety of severe operating conditions, such as thermal cycle, sudden electrical load change, and frequent electrical load cycle.
In this study, various accelerating degradation testing are performed to find the degradation patterns and disclose the main degradation mechanism of SOFCs. The durability of SOFCs are tested on a variety conditions of load trip and load cycle. The load trip is cycled at the current density of between 0 and 200 mA cm-2 at 700oC. Each step is held at 12 h and repeated 30 times. The load cycle is cycled under the current density of between 120 and 200 mA cm-2 at 700oC. Each step is held at 12 h and repeated 12 times. The thermal cycle is tested at 700oC and ramped down at 1℃ min-1 to 400oC. This step is repeated 30 times.
As a periodic diagnostic tool of I-V (current-voltage) characterization and electrochemical impedance analysis are performed cells, using an electrochemical impedance spectroscopy (EIS) with a Potentiostat/Galvanostant device using a frequency range from 1 MHz to 1Hz. The physicochemical analysis of tested cell are carried out using field emission-scanning electron microscopy (FE-SEM), transmission electron microscope (TEM), and X-ray diffraction (XRD).
1. Steele, Brian CH, and Angelika Heinzel. "Materials for fuel-cell technologies."Nature 414.6861 (2001): 345-352.
2. Yamamoto, Osamu. "Solid oxide fuel cells: fundamental aspects and prospects." Electrochimica Acta 45.15 (2000): 2423-2435.
3. Khan, Muhammad Shirjeel, et al. "Fundamental mechanisms involved in the degradation of nickel–yttria stabilized zirconia (Ni–YSZ) anode during solid oxide fuel cells operation: A review." Ceramics International 42.1 (2016): 35-48.
4. Hagen, Anke, et al. "Durability study of SOFCs under cycling current load conditions." Fuel Cells 9.6 (2009): 814-822.
* Corresponding author: jyoung@sejong.ac.kr (J.-Y. Park).
Quasi-Solid-State Dye-Sensitized Solar Cell with Ionic Gel Electrolytes By Semifluorinated Alkoxy Benzene Derivative
Authors: Cao Banpeng , Kaneshige Yuta , Morita Yuki , Okamoto Hiroaki 
Published: February 2020

Quasi-solid-state dye-sensitized solar cells (QS-DSSCs) have rapidly become an important research orientation in electronic vehicles. Especially, ionic liquid gel electrolytes (ILGEs) solidified by low molecular mass organogelators (LMOGs) can effectively possess higher ionic conductivity and good pore filling.1 Based on the advantage of ILGEs, we present here a kind of LMOGs (compounds 1(n)) by semifluorinated benzene derivatives.
ILGEs formed by compounds 1(n) with different ionic liquids can divide two parts. One is with the representative [BMIM] posion-based ionic liquids (ILs), such as [BMIM] [I], [BMIM] [BF4], [BMIM] [FSA] and [BMIM] [TFSA]. Another one is with the representative [TFSA] anion-based ILs, such as [DEME] [TFSA], [EMIM] [TFSA], [TMPA] [TFSA], [AAIM] [TFSA] and [P13] [TFSA]. The minimum gelation concentrations in weight percent were determined at concentrations ranging from 5% to 1% in a heating-cooling cycle by the “stable to inversion in a test tube” method. The thermal properties of ILGEs which exactly is the effect of the concentration on the gel-sol phase transition temperatures (T gel) upon heating were examined. The ionic conductivity (σ) of ILGEs which is an important property for ILGEs was also examined. Compared with the data of ionic conductivities which has been reported in literature, it was found that the ionic conductivities in gel state were similar with ionic conductivities in liquid state. The conductivities of ILGEs with different concentrations of LMOGs were also analyzed.
The diffusion of redox couple (I3
- and I-) ions in the ILGEs is an important factor for DSSCs property.2 In order to analyze the behavior of in I3
- and I- the ILGEs, linear sweep voltammetry studies were performed at a scan rate of 1.0 mVs-1 at room temperature. The performance of [BMIM] [I] was different with others. It maybe that ionic liquid of [BMIM] [I] contains anion of I- by itself.
Reference
1. (a) Wang, P.; Zakeeruddin, S. M.; Comte, P.; Exnar, I.; Grätzel, M. Gelation of ionic liquid-based electrolytes with silica nanoparticles for quasi-solid-state dye-sensitized solar cells. Journal of the American Chemical Society
2003,
125 (5), 1166-1167; (b) Tao, L.; Huo, Z.; Ding, Y.; Li, Y.; Dai, S.; Wang, L.; Zhu, J.; Pan, X.; Zhang, B.; Yao, J. High-efficiency and stable quasi-solid-state dye-sensitized solar cell based on low molecular mass organogelator electrolyte. Journal of Materials Chemistry A
2015,
3 (5), 2344-2352.
2. Yoon, J.; ki Kang, D.; Won, J.; Park, J.-Y.; Kang, Y. S. Dye-sensitized solar cells using ion-gel electrolytes for long-term stability. Journal of Power Sources
2012,
201, 395-401.
Morphology in Porous Silicon Prepared from Si-Nanowires Grown By Electroless Etching
Authors: Velez Victor H. , Sundaram Kalpathy B 
Published: February 2020

Porous silicon nanowires (SiNWs) shown remarkable advantages due to the chemical and physical properties [1]. These properties cause special interest in optoelectronics and sensing applications [2]. Porous silicon nanowires were prepared in an electrolytic solution concentration after grown these nanostructures in an electroless etching solution [3]. Changes in the morphology of porous SiNWs may be the result of increasing the concentration of the oxidizer (C2H6O) and etching time when these nanoparticles are etched in an electrolytic solution. SiNW arrays grown by electroless etching is shown in Figure 1a. Further changes are achieved in the diameter and length when the prepared electroless SiNW arrays are etched in an anodic solution to reduce its quantum confinement to obtain porous silicon nanowires, as shown in Figure 1b. Silicon nanowires were grown by electroless etching in an etching solution concentrations of hydrofluoric Acid (HF) and silver nitrate (AgNO3) at room temperature [4]. The prepared nanowires were then etched in an electrolytic solution containing HF and ethanol to make porous Si quantum confinement structures. SEM images were obtained for morphology analysis.

Figure 1
Directly-Grown Hierarchical Carbon Nanotube@Polypyrrole Core-Shell Hybrid on Carbon Cloth As a High-Performance Flexible Supercapacitor with High Cycle Stability
Authors: Shown Indrajit , Yesi Yesi , Chen Li-Chyong , Chen Kuei-Hsien 
Published: February 2020

Supercapacitors are attractive energy storage devices in the modern flexible and wearable electronics, owing to their high-energy density and high-power density in comparison with conventional capacitors and batteries, respectively. Among various pseudocapacitor materials, polypyrrole (PPy) is one of the most promising pseudocapacitor materials due to its easy polymerization, high conductivity, nontoxicity, and unique doping process with a wide range of dopant, a greater degree of flexibility than other conducting polymers, moderately high theoretical specific capacitance with potential operating potential window around 0.8 V and its good stability in ambient atmosphere. However, the PPy-based pseudocapacitor is still suffering from its limited cycling stability and high interfacial resistance.[1] In this study, we have fabricated hierarchical CNTs-PPy core-shell hybrid on flexible carbon cloth by binder free direct growth method for flexible supercapacitor application. In particular, deposition of in-situ doped PPy-shell on the CNT-core is done by simple electropolymerization with controlled shell thickness. Direct fabrication of electroactive (CNTs-PPy) materials on the flexible CC electrode could reduce the interfacial resistance between the electrode and electrolyte and improve the ion diffusion process. The supercapacitor electrode based on optimized PPy/CNTs-CC exhibits excellent electrochemical performance, indicating highest gravimetric capacitance around 486.1 F g-1 per active mass of the PPy/CNTs composite with excellent flexibility and cycle stability up to 10,000 cycles with only 18% capacitance loss.[2] At the same time, the fabricated asymmetric supercapacitor (PPy/CNTs-CC║CNTs-CC) shows the maximum power density of 10,962 W kg-1 at an energy density of 3.9 Wh kg-1 under the operating potential of 1.4 V. The detail pouch type symmetric and asymmetric supercapacitor performance together with electrochemical test will be discussed on the presentation.

References

[1] I. Shown, A. Ganguly, L.-C. Chen and K.-H. Chen, Energy Science & Engineering, 2015, 3, 2-26.
[2] Y. Yesi, I. Shown, A. Ganguly, T.-T. Ngo, L.-C. Chen, K.-H. Chen, ChemSusChem,
2016, 9,370-378.