bluuebunny/crossref_metadata_2025 huggingface dataset:
Conducting Molecularly Imprinted Polymer (MIP) Chemical Sensors for Toxic N-Nitrosamines Selective Determination in Heat Processed Food of Animal Origin
Authors: Kutner Wlodzimierz , Garcia-Cruz Alvaro , Lach Patrycja , Sharma Piyush Sindhu , Pieta Piotr , Golebiewska Karolina K. , Cieplak Maciej , Noworyta Krzysztof R. , Schulz Emmanuelle , D'Souza Francis
Published: February 2020

High-temperature processing of meat food generates in it toxic heteroaromatic amines and nitrosamines (NAs)1,2 causing chronic diseases including hormonal dysfunctions and cancer.3 Therefore, we devised and fabricated chemical sensors for selective determination of the N-nitroso-L-proline (Pro-NO)4 and N-nitroso-thiazolidine-4-carboxylic acid (NT4A) toxins in this food. We applied films of conducting polymers molecularly imprinted (MIPs) with either the Pro-NO or NT4A template as recognition units of these chemosensors. For selection of most appropriate functional monomers, we used DFT at the B3LYP/3-21G(*) level modeling to find phenolic derivative of bis(bithiophene) and a thiosalenCo(III) complex (CS)5,6 suitable to form pre-polymerization complexes with Pro-NO and NT4A, respectively, at the 1:2 template/monomer stoichiometry. The calculated Gibbs free energy gain due to formation of these complexes with a series of NAs was proportional to the UV-vis spectroscopy determined stability constants of these complexes. These constants were relatively high equalling 3.14×109 M-2 and 2.72×1010 M-2for Pro-NO and NT4A, respectively. Then, we electrochemically polymerized these complexes under potentiodynamic conditions. This electropolymerization resulted in depositing thin MIP films on different electrode substrates. After subsequent extraction of the Pro-NO and NT4A templates from MIPs, we used the resulting MIPs with empty imprinted cavities for determination of Pro-NO and NT4A analytes in grilled pork neck samples. We confirmed the presence and then absence of NA templates in the MIP films before and after extraction, respectively, with FTIR spectroscopy and XPS, and then characterized morphology of the films with AFM. For analytical signal transduction, we used piezoelectric microgravimetry (PM) at the Au-QCR/MIP electrodes of EQCM as well as DPV and EIS at the Pt/MIP electrodes. Limits of detection of the chemosensors were 36.9 nM Pro-NO (with EIS) and 46 nM NT4A (with DPV). The chemosensors selectively responded to the target toxins in the presence of interfering compounds of similar composition and structure. Successful selective determination of Pro-NO and NT4A in the food extract samples indicates that the chemosensors are promising as tools for determination of these toxins in food of animal origin.

References

1. Santarelli R. L. et al., Nutr. Cancer
2008, 60, 131.

2. Oostindjer, M. et al., Meat Sci.
2014, 97, 583.

3. Larsson S. C. et al., Int. J. Cancer
2006, 119, 915.

4. Lach P. et al., Chem. Eur. J.(2016) in press, DOI:10.1002/chem.201604799.

5. Pan, M.; et al., Biosens. Bioelectron.
2012, 31, 11.

6. Zhao, L.; et al., Sens. Actuators, B Chem.
2012, 171–172, 563.

Figure 1
A Paper-Based Lateral Flow Strip for Protein Biomarker Detection
Authors: Wu Nianqiang (Nick) , Gao Xuefei
Published: February 2020

Protein biomarkers are becoming increasingly important in diagnosis and monitoring of diseases. Paper-based test strip is a promising technique for sensing protein biomarkers in point-of-care (POC) applications. This talk will demonstrate our effort to develop a paper-based test strips for detection of Traumatic Brain Injury (TBI) protein biomarker in blood plasma by utilizing employing surface-enhanced Raman scattering (SERS) for signal transduction. The detection of limit (LOD) of this paper test strip for TBI protein biomarker is lower than the cut off value that is present in patient blood plasma. This paper-based lateral flow device has a potential application in POC setting.
Electrochemical Peptide-Based (E-PB) Sensor for the Detection of Uranium
Authors: Thompson Channing Christine , Lai Rebecca Y.
Published: February 2020

Metal ion sensing attracts significant attention as many metal ions that are introduced into natural waters as water waste from industrial processes are toxic to humans. Uranium is a radioactive heavy metal naturally present in the environment and largely found in its hexavalent oxidation state as the uranyl ion, UO2
2+. Anthropogenic activities such as mining, milling, and nuclear testing increase the distribution of groundwater contamination and in many regions in the United States contamination exceeds the U.S. Environmental Protection Agency (EPA) Maximum Contamination Level (MCL) of 30 µg/L (126 nM). Therefore, there is a need for developing sensitive, selective, and cost-effective analytical methods capable of identifying and quantifying uranium in environmental samples. In this study, we focus on understanding the interactions between uranium-binding peptides and UO2
2+ as well as exploiting these interactions in the design of electrochemical peptide-based (E-PB) uranium sensors. We are particularly interested in assessing the effect of threonine phosphorylation on uranium binding affinity of peptides. The peptide probe used in the fabrication of the first generation E-PB uranium sensor is a thiolated 12-amino acid peptide probe modified with methylene blue (MB). In the absence of the target, the probe is flexible and the MB current is high; in the presence of the target, the flexibility of the probe is dampened, resulting in a large reduction in the MB current. Our preliminary results show that the sensor is capable of specific detection of UO2
2+ at concentrations substantially lower than the EPA MCL (limit of detection = 10 nM). Like most E-PB sensors, it is also reusable and selective enough to be employed in 50% synthetic aquifer samples. With further optimization, this sensor could find applications in real time detection of uranium in complex environmental samples.
Preparation of Glucose Sensor for Low Invasive In Vivo Measurement
Authors: Yasuzawa Mikito , Li Jiang , Nakataki Shinsaku , Fuchiwaki Yusuke , Harada Toshihiko
Published: February 2020

A fine needle type glucose sensor, which has sensing region on the tip of a fine tapered electrode, was prepared using tapered PEEK tube with platinum-iridium alloy wire. Glucose oxidase was immobilized on the surface of Pt-Ir electrode using the combination of electrodeposition and electropolymerization procedures. The obtained sensor showed good response with sufficient linear relationship between response current and glucose concentration. Long-term stability of the obtained electrode was evaluated for 35 days. Constant response current was obtained for approximately 1 month.
Development of WO3 Nanoparticle Based pH Sensor
Authors: Jamal Mamun , Akhter Irani , Shao Han , Yousuf Mohammad A. , Razeeb Kafil M.
Published: February 2020

In biological and environmental applications, pH is an important parameter that needs to be monitored at a regular basis. Conventionally, the measurement process takes a considerable amount of time involving several calibration steps and handling of fragile electrodes. In this work, we propose a new, robust and reliable way of sensing pH. The sensor has been fabricated based on tungsten oxide nanoparticle modified glassy carbon electrode (WO3/GCE) (Fig. 1). WO3 is a promising material for pH sensor because of its availability, stability, good morphological and structural control of the synthesized nanostructures, reversible change of conductivity, high sensitivity, selectivity and biocompatibility.1 Furthermore, WO3 is a well-studied wide band gap semiconductor (~2.75 eV) used for several applications as chromogenic material and catalyst.2

In this work, hydrothermal synthesis method was used for the fabrication of WO3 nanoparticles. For the fabrication of the pH sensor, the nanoparticles were mixed with Nafion and chitosan before drop coating onto the GCE surface. Scanning electron microscopy (SEM), x-ray diffraction (XRD), transmission electron microscopy (TEM) was used to characterize the nanoparticles. Cyclic voltammetry (CV) and square wave voltammetry (SWV) were used to monitor the potential shift based on different pH in the buffer solution. The WO3/GCE pH sensor showed a sensitivity of 1.15 VpH-1cm-2 at 25 °C and a potential drift of less than 5% after three hours of continuous use. The sensor showed good linearity at a pH range of 3 -10 and could retain 95% of its initial sensitivity after 1 week of use. The good sensitivity and long term stability of this WO3 based sensor may allow the development of a low cost pH sensor for a wider range of applications.3

Acknowledgement

This work is financially supported by Science Foundation Ireland funded project “SweatSens” under the grant agreement No. 14/TIDA/2455 and the University Grant Commission (research support and publication division), Bangladesh.

Corresponding authors' email addresses: mamun.jamal@chem.kuet.ac.bd and kafil.mahmood@tyndall.ie

Reference

1. D. Vernardou, H. Drosos, E. Spanakis, E. Koudoumas, C. Savvakis, N. Katsarakis, J. Mater. Chem., 2011, 21, 513.

2. M. Natan, T. E. Mallouk, M. S. Wrighton, J. Phys. Chem. 1987, 91, 648.

3. L. Devlin, M. Jamal and K. M. Razeeb, Anal. Meth. 2013, 5, 880.

Figure 1. Schematic diagram of WO3 nanoparticle based pH sensor.

Figure 1
Paper Microfluidic Electrochemical Sensor for Salivary Cortisol Analysis
Authors: Fernandez Renny Edwin , Manickam Pandiaraj , Bhansali Shekhar
Published: February 2020

Cortisol is an accurate biomarker of stress; found abundantly in serum and saliva. Continuous monitoring of cortisol over a span of 24 hours can yield important information on a person’s stress level and endurance. The current gold standards of cortisol analysis are lab centric and not point of care. We present a paper-microfluidic electrochemical sensor specifically designed for cortisol detection from saliva samples.

Graphene electrodes were screen printed on paper along with a layer of Zinc Oxide- metalloporphyrin for enhanced electrochemical detection. The proposed cortisol sensor is based on a competitive binding assay, conducted in a paper reaction site. Response of the sensor was found to a strong linear function of cortisol concentrations in the 50 pM-100 nM range. Limit of detection was found to be as low as 10 pM. The proposed sensing technique was used to detect cortisol levels in clinical saliva samples. In comparison to existing techniques for cortisol detection, our method does not rely on immobilized affinity probes. Rather a magnetic bead based approach has been adopted to deliver the samples to the electrochemical site

Figure 1
Cu-Sb Alloys As Electrode Materials for Lithium Ion Batteries; Thermodynamics, Electrochemistry and Structural Aspects
Authors: Beutl Alexander , Flandorfer Hans , Effenberger Herta Silvia
Published: February 2020

Cu-Sb alloys have recently gained much attention as promising electrode materials for lithium ion batteries. Sb, as the active agent, has a theoretical capacity of 660 mAhg-1, forming Li3Sb in the fully lithiated state. Cu on the other hand does not react with lithium and can precipitate upon lithiation of Cu-Sb alloys. The Cu matrix is mandatory, as the change in volume between pure Sb and Li3Sb is about 200% and therefore the structural integrity of the electrode material is compromised by the mechanical stress built up upon cycling of the cell.

Although much information is already available on the cycling performance of Cu-Sb electrodes, almost no data on the thermodynamics behavior exists. This is surprising as many thermodynamic parameters have a direct correlation to the electrochemical performance as well as kinetics of a material system. Therefore an extensive experimental investigation was conducted in the system Cu-Li-Sb, applying thermochemical as well as electrochemical methods.

Our investigations started with the development of fundamental property diagrams like isothermal sections and isopleths in the system Cu-Li-Sb. Thereby yet unknown ternary compounds were found and structurally characterized. On the basis of this data, reaction paths for the lithiation of different Cu-Sb alloys were proposed and further validated by electrochemical investigations, i.e. coulometric titrations. Reasons for the good cyclability of Cu-Sb alloys were found to be deeply rooted in the structural relations of the ternary compounds formed upon lithiation and their corresponding binary counterparts β-Cu3Sb and Li3Sb.

This work has been funded by the DFG under project FL-730/1-2 within the priority program SPP 1473 “WeNDeLIB”.
Cycling Performance of Lithium Iron Sulphate in the Presence of Binders and Carbon Additives
Authors: Muthiah Aravind , Copley Mark , Srinivasan Madhavi
Published: February 2020

Fe-based high voltage positive electrode material Li2Fe(SO4)2 has shown consistent cycling only in experimental Swagelok cell configurations.[1, 2] In order for it to be practically viable, knowledge of its interaction with commercially used additives in the coating process is lacking. Thus, this work seeks to study the cycling performance of Li2Fe(SO4)2in a half cell configuration with different types of binders and carbon based additives as a step towards commercial utilisation of the material.

Flourinated binder polvinylidene fluoride (PVDF) and non-fluorinated binder polyacrylonitrile (PAN) were both evaluated and shown to perform similarly. The long term cycling at low C-rates was found to be consistent for the systems with and without binder. However, at high C-rates a significant fall in capacity of nearly 60% was observed for the system with binders in comparison to the system without binder.

Li2Fe(SO4)2 being polyanionic has poor electronic conductivity and requires carbon coating to enhance performance. This study investigates the effects of amorphous Super-P Carbon, Multi Walled Carbon Nanotubes and Single Walled Carbon Nanotubes when ball-milled with the electrode material. The carbon-coated material was then subjected to galvanostatic charge discharge tests over multiple cycles and at different charging rates. This study on the effect of binders and carbon additives lays the foundation for future work on an all-iron lithium battery and is a step forward in commercialising sulphate based cathode materials.

[1] M. Reynaud, M. Ati, B. C. Melot, M. T. Sougrati, G. Rousse, J.-N. Chotard, et al., "Li2Fe(SO4)2 as a 3.83 V positive electrode material," Electrochemistry Communications, vol. 21, pp. 77-80, 2012.

[2] L. Lander, M. Reynaud, G. Rousse, M. T. Sougrati, C. Laberty-Robert, R. J. Messinger, et al., "Synthesis and electrochemical performance of the orthorhombic Li2Fe (SO4) 2 polymorph for Li-ion batteries," Chemistry of Materials, vol. 26, pp. 4178-4189, 2014.

Figure 1
Electrochemical Mechanism of Room Temperature Sodium/Sulfur Battery with Tegdme Electrolyte
Authors: Kim Icpyo , Kim Changhyeon , Kim Hui-Hun , Kim Ki-Won , Ahn Jou-Hyeon , Ahn Hyo-Jun
Published: February 2020

The high temperature Na/S battery working above 300°C has been highlighted as a promising candidate for large scale energy storage systems. It carries many advantages such as low-cost raw materials, high energy density (760 Wh kg-1), high coulombic efficiency, and a long cycle life. However, it suffers from critical problems of the safety issue, etc. For example, sulfur and sodium polysulfides are in the liquid state and react with sodium vigorously. In the case of a failure of solid electrolyte separator (β"-Al2O3), a fire or an explosion can take place.

The room temperature Na/S battery with tetraethylene glycol dimethyl ether (TEGDME) electrolyte (hereafter referred to as the Na/S battery) can overcome these drawbacks. Furthermore, assuming Na2S as the final discharge product, sulfur cathode has a high theoretical specific capacity of 1672 mAh g-
1 and the Na/S battery has a high theoretical energy density of 1230 Wh kg-1.

Sulfur in the Na/S cell has been reported to involve complicated transition processes during charge/discharge. It evolves from S8 to Na2S through various sodium polysulfides such as Na2S6, Na2S5, Na2S4, Na2S3 and Na2S2 during the discharge and does reversely during charge. Especially, the high-order polysulfides (Na2Sn, 4 ≤ n ≤ 8) are generally believed to dissolve into the TEGDME electrolyte, bringing a number of drawbacks such as low discharge capacity, fast capacity decay during cycling and deterioration of the sodium anode due to the shuttle effect. Thus, some strategies such as a solid electrolyte separator (β"-Al2O3), ion selective polymer membranes, and interlayers have been applied to suppress the shuttle effect of the high-order polysulfides (Na2Sn, 4 ≤ n ≤ 8). Inversely, there have also been several studies such as catholyte system to use their soluble properties. The low-order ones (Na2Sn, 1 ≤ n ≤ 3) are considered to generally be in the solid state and contribute to the low discharge capacity and high polarization due to the low electronic and ionic conductivities. These mean that understanding the evolution of sulfur in the cathode to sodium polysulfides (Na2Sn, 1 ≤ n ≤ 8), based on solubility, is critical for understanding and developing the Na/S battery. However, previous studies have focused only on identifying the chemical species of sodium polysulfides (Na2Sn, 1 ≤ n ≤ 8), which were even partially identified, and there has been no study on the Na/S battery in viewpoint of the solubilities of sodium polysulfides (Na2Sn, 1 ≤ n ≤ 8).

In the present study, we aim to investigate the formation and variation of sodium polysulfides during charge/discharge. Sulfur cathode and sodium anode are examined at different points of the charge/discharge by separating both electrodes with the beta alumina solid electrolyte separator (β"-Al2O3). The solubilities of sodium polysulfides of Na2Sn (1 ≤ n ≤ 8) are measured and compared to the sulfur cathode visually.
Structural Transformations in High Capacity Li2Cu0.5Ni0.5O2 Cathodes
Authors: Ruther Rose Emily , Pandian Amaresh Samuthira , Yan Pengfei , Weker Johanna Nelson , Wang Chongmin , Nanda Jagjit
Published: February 2020

Cathode chemistries with more than one lithium per transition metal (multi-lithium cathodes) are one approach for increasing the energy density of lithium-ion cells. Examples include lithium-rich NMCs (xLi2MnO3·(1−x)LiMO2 where M=Mn, Ni, Co), anti-fluorite type oxides, and several polyanionic compounds. Many of these cathodes have very high theoretical capacities, but none has proven practical for commercial cells. These materials generally undergo structural transformations, often accompanied by oxygen loss, which limit electrochemical reversibility. In this contribution, we present a thorough investigation of Li2Cu0.5Ni0.5O2, as a model system to understand the larger family of multi-lithium cathodes. Results from XRD, Raman spectroscopy, TEM, XANES, and gas evolution measurements follow the chemical, structural, and morphological changes that occur during electrochemical cycling. Our study broadly demonstrates the challenges associated with multi-lithium transition metal oxides, where there is close interplay between structure, transport, and oxygen loss that limits their use as high capacity cathodes for advanced lithium-ion systems.

 

Acknowledgement

Research has been supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the U.S. Department of Energy through the Advanced Battery Materials Research (BMR) Program. The authors acknowledge the support of Stanford Synchrotron Radiation Lightsource, a Directorate of SLAC National Accelerator Laboratory and an Office of Science User Facility operated for the U.S. Department of Energy Office of Science by Stanford University. X-ray diffraction was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. The TEM work was conducted in the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL), a DOE User Facility operated by Battelle for the DOE Office of Biological and Environmental Research. Pacific Northwest National Laboratory is operated for the DOE under Contract DE-AC06-76RLO 1830.
Scalable Template-Free Synthesis of Na2Ti3O7/Na2Ti6O13 Nanorods with Composition Tunable for Synergistic Performance in Sodium-Ion Batteries
Authors: Ho Ching-Kit , Li Chi-Ying Vanessa , Chan Kwong-Yu
Published: February 2020

Sodium-ion batteries are regarded as one of the potential candidates to substitute lithium ion batteries in large-scale electric energy storage applications in the near future. Several forms of sodium titanates including Na2Ti3O7, Na2Ti6O13 and Na4Ti5O12 have recently been applied as anode in sodium ion batteries. Here, we present an energy-efficient solid-state synthesis, via the addition of carbon, to mass-produce a series of uniform and single-crystalline Na2Ti3O7/Na2Ti6O13 nanorods with tunable composition as anode materials for sodium-ion batteries.1 Due to the extra local heat generation and CO2/CO release from carbon oxidation, the carbon added in the synthesis provides an alternative low-temperature route for the Na2Ti3O7 formation at 450 °C, a reaction temperature much lower than that of conventional solid-state methods (750–1000 °C), and Na2CO3 is regenerated to be recycled in the synthesis. The high theoretical capacity of Na2Ti3O7 and low volume expansion of Na2Ti6O13 upon charge–discharge are synergistically exploited to achieve high electrochemical performance and stability.

References

1. Ho, C.-K.; Li, C.-Y. V.; Chan, K.-Y., Scalable Template-Free Synthesis of Na2Ti3O7/Na2Ti6O13 Nanorods with Composition Tunable for Synergistic Performance in Sodium-Ion Batteries. Industrial & Engineering Chemistry Research
2016,
55 (38), 10065-10072.

Acknowledgements

This project is financially supported by Research Grants Council of Hong Kong (GRF 17300014), HKU Small Project Funding (201409176115), HKU Strategic Research Theme on Clean Energy, and University Development Fund for Initiative for Clean Energy and Environment.

Figure 1
Design Principles for Graphene-Based Materials to Enhance Supercapacitor Performance
Authors: Paek Eunsu , Pak Alexander , Hwang Gyeong S
Published: February 2020

Carbon-based nanomaterials are a promising class of electrodes for electrochemical double layer capacitors, due to their high accessible surface area, high electrical conductivity, and tunability through functionalization. A series of recent studies have shown that chemically and mechanically modified graphene electrodes can have improved capacitance, which has been typically to be associated with the increased double layer capacitance from a high BET surface area or an enhanced electrolyte-electrode interfacial interaction. However, the influence of the electrode’s quantum capacitance is relatively unknown. In this talk, we will present a computational framework based on density functional theory and classical molecular dynamics to explore the relative contributions of the quantum capacitance of electrode (CQ
) and the electric double layer (CD
) capacitance to the total interfacial capacitance (CT
) for various carbon electrode systems in ionic liquids (ILs). For instance, our study suggests that N-doping leads to significant enhancement in CQ
as a result of electronic structure modifications while there is virtually no change in CD
. We will discuss the impact of the chemical and/or mechanical modifications of graphene-like electrodes on the CT
and the design principles to enhance supercapacitor performance.
Investigating the Solid Electrolyte/Electrode Interfaces with X-Ray Absorption Spectroscopy
Authors: Vardar Gulin , Lu Qiyang , Wang Jiayue , Seibert Rachel , Lee Zhengrong , Chiang Yet-Ming , Terry Jeff , Yildiz Bilge
Published: February 2020

Solid-state lithium-ion batteries hold great promise for obtaining higher energy densities but the power density is currently limited by the electrode-electrolyte interfaces. [1] The high resistances at SLIB interfaces are hypothesized to be due to chemical mixing, space charge formation, or secondary phase formation. [2,3] Although several secondary phases have been proposal theoretically, there is no experimental work studying the secondary phase formation as a function of temperature and applied voltage. Extended x-ray absorption fine structure spectroscopy (EXAFS) is a unique capability that allows us to probe the fine structure around the atoms at the electrode-electrolyte interface. Previous interface studies using XRD were not able to identify the secondary phases, either because secondary phases are small in amount or not crystalline. [3] Depth-sensitive x-ray absorption spectroscopy allows us to probe the changes in structure at the interface even if the secondary phases are not crystalline. This work studies the interface between Li7La3Zr2O12 (LLZO) and LiCoO2 (LCO).

[1] Cheng, L. et al.
Phys. Chem. Chem. Phys.
16, 18294–18300 (2014).

[2] Miara, L. J., et al. Chem. Mater.
27, 4040–4047 (2015).

[3] Park, K. et al.
Chem. Mater.
28, 8051–8059 (2016).
Synthesis of MoS2/Reduced Graphene Oxide/Si-Nanopowder Composite As an Anode Material for Li-Ion Batteries
Authors: Abdillah Setiawan , Ting Jyh-Ming
Published: February 2020

In this study, a novel three-system composite MoS2/rGO/Si-nanopowders was developed as an anode material for Li-ion batteries. The addition of Si nanopowders, which is reported as the anode material with the highest specific capacity for energy storage, further improved the widely investigated composite MoS2/rGO anode for Li-ion batteries. MoS2­/rGO composite was first synthesized through a hydrothermal method. Then, Si nanopowders were added to the matrix between MoS2/rGO through a milling method. Composites having different ratios of Si nanopowders, MoS2, and rGO were investigated in order to optimize the perfomance of the anode material. The electrical properties of the synthesized battery samples were evaluated using cyclic voltametry and charging-discharging test.
Conditioning Safety Index of Ni-Rich Cathode Oxides for Lithium Ion Batteries
Authors: Gim Jihyeon , Yonemoto Bryan T , Liu Jianzhao , Gao Han , Xu Gui-Liang , Amine Khalil , Chen Zonghai
Published: February 2020

Ni-rich cathode materials with high energy density has degradation issue of electrochemical performance due to the significant side reaction between electrolyte and cathode. To solve this, a Full Concentration Gradient (FCG) materials consisting of a high-Ni core and a relatively high-Mn outer layer was designed to provide improved stability as well as cycle life characteristic. However, a Ni-rich core still has some possibilities to be contact with electrolyte, especially if the particle in the core part is unexpectedly porous. We found the strategy to tune the particle porosity by controlling a feed rate of transition metal sulfate solutions and ammonium hydroxide solution during co-precipitation synthesis using Continuous Stirred Tank Reactor (CSTR). Additionally, the effect of surfactant was studied in the standpoint of the electrode stability. The structural characteristics was compared for the materials obtained by different feed rate with analysis of by X-ray diffraction, electron microscopy and dynamic light scattering. The interfacial kinetic reaction between the delithiated Ni-rich cathode and a nonaqueous electrolyte was investigated by our home-built high-precision leakage current measurement system. The result of this study indicated a different reaction phenomenon and further implies that the safety of Ni-rich cathode by co-precipitation could be controlled.
Imidazolium Based Dicationic Ionic Liquids As Electrolyte for Lithium Ion Batteries
Authors: Yen Yung-Che , Sun I-Wen
Published: February 2020

Two imidazolium based dicationic ionic liquids(DILs), one with ether bridged structure, and the other with carbon chain bridged only(figure 1.), were synthesized and used as electrolyte for lithium ion battery, to evaluate whether the ether bridge structure would improve the performance of the lithium ion battery using ionic liquid electrolyte.

The half-cells were composed with LiFePO4cathode and lithium metal as anode. The mixed electrolyte included DIL, 0.5m lithium salt(LiTFSI), and sulfolane as additive to reduce viscosity and increasing conductivity. At high discharging rate, the specific capacity of the cell with ether bridged DIL showed significantly better performance than the other without ether bridged structure. For example, at 3C rate, the cell with [IMOI] mixed electrolyte showed a specific capacitor of 130mAh/g, but the one with [IMCI] had 88mAh/g only.

Figure 1
Colloidally Assisted Synthesis to Phase Pure Na0.43Ni0.25Mn0.75O1.9 with Suppressed P2/O2 Phase Transition As High Stable Cathode for Na-Ion Batteries.
Authors: Chen Lin , Monaco Simone , Marras Sergio , Bertoni Giovanni , Palazon Francisco , Manna Liberato
Published: February 2020

P2-Na2/3[NixMny]O2-based cathode materials are promising candidates for Na-ion batteries. The cycling performance of these cathodes was usually reported to drop at working voltages over 4.2 V, due to the P2/O2 irreversible phase transition. Here we demonstrate a colloidally assisted two-step synthesis to phase pure P2-Na0.43Ni0.25Mn0.75O1.9. The adopted synthetic route and the chosen Na:Ni:Mn ratio (0.43:0.25:0.75) leads to a cathode material that can withstand long charge/discharge cycles at working voltages up to 4.4 V. The XRD pattern recorded on the de-sodiated electrode (4.4 V) does not evidence the presence of any peak related to the O2 phase, corroborating the effective suppression of the P2/O2 phase transition upon Na+ intercalation/deintercalation. The discharge capacity delivered at relatively low current (C/10) is 109 mAh g-1, with a capacity retention exceeding the 93% in 20 cycles. At the high current of 1C the delivered discharge capacity is 94 mAh g-1.
(Invited) Energetic Basis of Aqueous-Two-Phase Separation of Single Wall Carbon Nanotube Enantiomers
Authors: Jagota Anand
Published: February 2020

Hybrids of single stranded DNA and single walled carbon nanotubes (SWCNTs) have proven very successful in selecting various chiralities and, recently, enantiomers of carbon nanotubes using aqueous two-phase (ATP) separation. This technique sorts objects based on small differences in hydration free energy, which is related to corresponding small differences in structure. Separation by handedness requires that a given ssDNA sequence adopt different structures on the two SWCNT enantiomers. In this talk we will discuss two aspects of the ATP separation process. Firstly, we study the physical basis of such selectivity using a coarse grained model to compute the energetics of ssDNA wrapped around an SWCNT. Our model suggests that difference by handedness of the SWCNT requires spontaneous twist of the ssDNA backbone. We also show that differences depend sensitively on the choice of DNA sequence. Secondly, we present a method by which measurements of partitioning by ATP can be used to rank quantitatively the solute solvation free energy.
(Invited) Evolution of Catalyst Role in Single Wall Carbon Nanotube Growth
Authors: Harutyunyan Avetik R
Published: February 2020

Undoubtedly, the catalyst plays a key role in the nucleation and growth of various carbon filaments, as evidenced by the large number of studies for more than 40 years that focus on catalyst preparation methods, composition, morphology and size. Variation of catalyst compositions have led to morphological control of grown carbon filaments such as vermicular, twisted, platelet, tubular and conical. Reduction of the catalyst nanoparticle size to the 1–5 nm range resulted in the formation of new allotrope, carbon nanotubes, with unique properties that depend on their structure. It is commonly accepted that a careful designed catalyst could control the structure of grown single walled carbon nanotubes and thereby their properties. However, a catalyst a few nanometers in diameter introduces peculiarities for classical understanding of the features e.g., melting temperature, binary/ternary phase diagrams with carbon and other metals, equilibrium shape (Wulff construction), crystallographic structure, impact of the substrate, etc. Current state of the art of thermodynamics and kinetics of nanoparticles for controllable growth of carbon nanotubes and challenges will be presented and discussed.
(Invited) Seamless Graphene-Carbon Nanotube (GCNT) Electrodes
Authors: Tour James M.
Published: February 2020

Reaching the maximum Li storage capacity in Li-ion batteries (LIBs) has been impractical because it requires the use of Li metal itself as the anode. Problematically, Li metal forms dendrites and related unstable structures during battery operation. This results in low coulombic efficiency and cycle life and poses serious safety concerns as the dendrites can cause short circuits. The approaches reported to date either limited Li storage capacity per unit electrode area and cycle life, or they restricted the current density since dendrite formation is more rapid and severe at higher current density. We report here a seamless graphene-carbon nanotube (GCNT) electrode that is capable of reversibly storing large amounts of Li metal with complete suppression of dendrite formation. The GCNT serves as a host material to insert and form Li as a thin coating over its high surface area (~2600 m2 g-1). With a Li storage capacity up to 4 mAh cm-2 (823 mAh cm-3) and 25.3 Ah g-1
G-CNT, the GCNT stores 6.6 times its weight in Li, 68 times greater than does graphite (372 mAh g-1
C), 6.6 times greater than does Si (3859 mAh g-1
Si), and far exceeds other Li storage materials. The capabilities, reversibility, and dendrite-free nature of the GCNT bode well for its use as a model structure for electrodes in secondary batteries.
(Invited) Carbon and Non-Carbon Nanomaterials for Sustainable Energy
Authors: Arepalli Sivaram
Published: February 2020

For the last two decades, nanomaterials (NMs) have been successfully processed to impart superior mechanical, electrical and chemical properties to the materials used in innovative energy technologies that are critical for a sustainable energy future. It is important to know the possibilities as well as limitations of the use of NMs in providing sustainable solutions for issues of all forms of energy. The present talk will focus on the applications of carbon nanostructures (fullerenes, carbon nanotubes and graphene) and metal oxides (ZnO and TiO2) for light weight composites for terrestrial and space transportation [1,2]; energy production such as solar cells and fuel cells; energy storage using supercapacitors [3,4] and batteries; and energy transmission using quantum wires. Incorporation of NM nanocomposite structures are being pursued for applications of hydrogen storage [5] as well. Life cycle assessment of these NMs as well as the environmental, health and safety considerations will be discussed.

References:

1) Bismark Mensah, Han Gil Kim, Jong-Hwan Lee, Sivaram Arepalli and Changwoon Nah, “Carbon nanotube-reinforced elastomeric nanocomposites: a review”,
International Journal of Smart and Nano Materials
, Vol. 6, pp. 211-238 (2016).

2) Sivaram Arepalli and Padraig Maloney, “Engineered nanomaterials in aerospace”,
MRS Bulletin
Vol. 40, Issue 10, pp 804-811 (2015).

3) Srikrishna Pandey, Uday N. Maiti, Kowsalya Palanisamy, Pavel Nikolaev, and Sivaram Arepalli “Ultrasonicated Double Wall Carbon Nanotubes for Enhanced Electric Double Layer Capacitance”,
Appl. Phys. Lett.
Vol. 104, 233902 (2014).

4) Hae-Kyung Jeong, Meihua Jin, Eun Ju Ra, Kyeu Yoon Sheem, Sivaram Arepalli and Young Hee Lee, “Enhanced Electric Double Layer Capacitance of Graphite Oxide Intercalated by Poly Sodium 4-Styrensulfonate with High Cycle Stability”,
ACS Nano,
Vol. 4, pp. 1162-1166 (2010).

5) N. F. Attia, S. Arepalli, and K. E. Geckeler, “Polyaniline-inorganic nanotube composites: potential hydrogen storage materials at room temperature”,
International Journal of Hydrogen Energy, Vol. 38, pp. 9251-9262 (2013).

Figure 1
Study of Spectral Analysis and Redox Potential Titration for Monitoring the State-of-Charge of Vanadium Redox Flow Battery
Authors: Hsieh Chin-Lung , Hung Yu-Hsun , Hsueh Kan-Lin , Hung Ju-Shei
Published: February 2020

Vanadium redox flow battery (VRFB) is currently the most mature technology of MW-level electricity storage. At present, the open circuit voltage of the electrolyte (OCV) is used to estimate the battery SOC (state-of-charge). Theoretically, the battery SOC cannot be estimated by measuring battery OCV along. Two analytical methods, UV-VIS absorption spectroscopy and redox electrode potential titration, were evaluated for assessing the electrolyte SOC. The UV-VIS spectra of solutions containing pure V2+, V3+, VO2+ ions can be identified. However, solutions containing a mixture of these ions cannot be easy identified. Redox potential titration analysis can identified individual ions from electrolyte sampled from positive electrode and negative electrode at SOC at 10%, 50%, 90%. Both OCV and UV-VIS are in-situ SOC monitoring method. The electrolyte composition is needed to be checked by redox potential titration at regular basis.
Linking Initial Microstructure to Microstructure Evolution and Conductivity Change in SOFC Electrodes: A Phase Field Simulation
Authors: Lei Yinkai , Cheng Tian-Le , Wen You-Hai
Published: February 2020

Microstructure evolution driven by thermal coarsening is an important factor for degradation of SOFC electrode. In this work, the effect of an initial microstructure on the microstructure evolution in SOFC electrode is investigated using a recently developed phase field model. Specifically, we tune the phase fraction, the average grain size, the standard deviation of the grain size distribution and the grain shape in the initial microstructure, and explore their effect on the evolution of the grain size, the density of triple phase boundary, the specific surface area and the effective conductivity in Ni-YSZ anode and LSM-YSZ cathode. It is found that the rate of coarsening and property degradation is lower with greater YSZ fraction, greater average grain size, smaller standard deviation of grain size distribution and smaller grain aspect ratio. The implication of this study on the designing of an optimal microstructure of SOFC electrodes will be discussed.
Effects of High-Porosity Conductive Foams on the Electrochemical Performance of Electrochemical Flow Capacitors
Authors: Akuzum Bilen , Agartan Lutfi , Hudson Deb , Gogotsi Yury , Kumbur E. Caglan
Published: February 2020

Electrochemical flow capacitors (EFCs) are high-power, long-cycle life electrochemical systems that utilize flowable suspensions of activated carbon in certain electrolytes. The unique capability of flowable electrodes, which offers ease of scalability, has found many applications not only in the field of energy storage but also in capacitive deionization [1-2]. Currently, one major challenge that prohibits widespread adaptation of EFCs is the low electrical conductivity of the flowable electrodes when compared to the conductivity of the film electrodes. This is mainly caused by the high percentage of the electrolyte phase in the suspension, which is not electrically conductive. Hence, presence of readily formed electron percolation paths is of critical importance to ensure all particles have a viable electron transfer path towards the current collectors [3].

Here, we hypothesized that large pore size conductive foams such as reticulated vitreous carbons (RVCs) could offer a stationary electron transfer backbone for EFC cell fixtures and help decrease the inter-particle electron conduction distance in large channel thicknesses. Contrary to the common approach used in flowable electrochemical systems, currently proposed cell fixtures for flowable electrodes does not involve any high-surface area electrodes due to concerns over clogging and other flow related issues. Motivated by this, this study aims to investigate the feasibility of high-porosity conductive foams as three-dimensional current collectors in EFC cell fixtures. To accomplish this, flow cells containing RVCs selected from different porosities have been subjected to electrochemical testing under static and intermittent flow conditions. For the same electrode composition, a significant improvement in capacity (up to 2x) and in power density (up to 10x) has been observed with the utilization of conductive foams in the cell fixtures.

References

[1] B. Kastening, Berichte der Bunsengesellschaft für physikalische Chemie, 1988, 92, 11, 1399-1402.

[2] K. B. Hatzell, M. Boota and Y. Gogotsi, Chemical Society Reviews, 2015, 44, 8664-8687.

[3] C. R. Dennison, Y. Gogotsi, and E. C. Kumbur, Phys. Chem. Chem. Phsy., 2014, 16, 18241-18252.
Effect of Alumina Addition on Li6.75La2.75Ca.25Zr1.5Nb.5O12 Lithium Garnet
Authors: Limpert Matthew , Hitz Gregory T , McOwen Dennis W. , Atwater Terrill B , Wachsman Eric D.
Published: February 2020

Lithium-conducting garnets are a promising solid state electrolyte in the cubic phase for lithium (Li) batteries because of their stability with lithium, wide electrochemical stability window, and high conductivity (~1 mS cm-1). Aluminum (Al) is a widely studied dopant due to its ability to stabilize the cubic phase because of the occurrence of unintentional doping from alumina crucibles used during synthesis. The quantity of aluminum in the material is critically important to sintering conditions and performance in both the bulk and at the grain boundaries. Al can diffuse into the structure of garnets and dope the Li site while removing three total Li for charge balance. Another possibility is the Al reacts with excess lithium or lithium that has left the structure during high temperature processing. This allows for a liquid phase to form, enabling better densification during sintering. In this work, the aluminum content in Li6.75La2.75Ca.25Zr1.5Nb.5O12 was varied and calcined in magnesia crucibles to limit Al contamination. One weight percent of alumina (0.1 moles) was added before the solid state reaction, producing a conductivity of 2.96 x 10-4 S cm-1 after sintering at 1100°C. Specifically in the sample with 0.1 Al added when sintered at 1100°C for 12 hours, the Al contributed to an increase in grain boundary conductivity to 1.96x10-3 S cm-1 and a decrease in total activation energy to 0.35 eV versus samples without any added aluminum. The varying Al content showed little variance in bulk conductivity over several sintering conditions, while showing a wide divergence of 2.72x10-3 S cm-1, in grain boundary conductivity. Possible explanations are discussed with structural, chemical, and EIS measurements detailed.
Transition Metal Oxide Powders Made from Flame Spray Pyrolysis for Li-Ion Batteries
Authors: Liao Jinyun , Smith Taylor , Hamad Khaleel , Xing Yangchuan
Published: February 2020

Flame spray pyrolysis process provides a cost effective way to make metal oxide powders. When the solvent is a green chemical, the process could become a sustainable manufacturing process for materials production. In this presentation, we will show that transition metal oxide powders can be produced in a flame spray process with a green solvent as the metal oxide precursor. It is also shown that complex transition metal oxide powders, such as Li(Ni1/3Mn1/3Co1/3)O2 and Li(Ni0.8 Co0.15 Al0.05)O2, can be produced in this process. These powders can be controlled to a certain degree in terms of powder sizes and morphology, to make them suitable for use in Li-ion batteries. Detailed results of the powder synthesis, characterization, and battery testing will be presented.
High Potential Organic Materials for Battery Applications
Authors: Guarr Thomas F. , Dumitrascu Adina , Prins Amber J. , Mortimer Nicholas , Henton Daniel R.
Published: February 2020

Many organic heterocyclic compounds undergo reversible one-electron electrochemical oxidation. However, in order to function effectively as redox shuttles in lithium batteries, such materials must display such behavior at potentials exceeding 4.2 V vs Li/Li+, and designing compounds that meet this requirement yet remain stable in the cation radical form represents a significant challenge. We have developed two families of organic heterocycles suitable for battery applications; namely appropriately substituted carbazoles and phenothiazine 5,5-dioxides.

We will describe the synthesis and characterization of these compounds, along with preliminary results of testing in lithium ion batteries and redox flow batteries.

Figure 1
A New Perspective on the Kinetics of Atmospheric Aluminium Pitting Corrosion
Authors: Trueman Antony
Published: February 2020

The atmospheric aluminium alloy pitting corrosion behaviour shown in the literature and here indicted that the maximum pit sizes measured versus duration did not fit either cathodic or anodic limited growth kinetics. To further elucidate the pit growth mechanisms environmental data was analysed using statistical simulations, and a series of pseudo atmospheric exposure tests were performed. The statistical analysis pointed towards a “packet” mechanism of atmospheric pitting corrosion. In other words packets or populations of corrosion pits are created when aluminium surfaces are atmospherically wet. The individual pit growth is initiated when surface wetness occurs, the pits propagate whilst the surface remains wet and terminate when the surface dries. These pits do not then grow during subsequent wetness, and “packets” of pits are created during each wetness period. This mechanism was verified by the laboratory testing that demonstrated that rapid pit growth during the relative humidity (RH) induced wetness periods could account for the long term atmospheric pitting observations. The growth kinetics of pits under droplets was shown to be under cathodic limitation that was approximately equivalent to the oxygen reduction kinetics on the aluminium surface.
New Method for Monitoring Hydrogen Evolution of Magnesium Alloys Under Atmospheric Exposure
Authors: Strebl Michael , Virtanen Sannakaisa
Published: February 2020

Magnesium (Mg) alloys are attractive lightweight materials for the automotive industry due to their low density and high specific strength [1]. However, widespread use of Mg alloy components is hindered by their corrosion properties. Full immersion conditions are frequently used to study the corrosion behavior, although Mg alloys are typically subjected to atmospheric corrosion environments in most applications. With a limited amount of electrolyte, the corrosion mechanism can be different [2]. For example, corrosion products that partly dissolve in a bulk electrolyte can remain at the surface and block active sites in the case of atmospheric conditions [3]. Effects of micro-galvanic coupling of secondary phases can be reduced with thin electrolyte films [4]. In addition, atmospheric concentrations of CO2 can influence the surface pH and change the composition of the corrosion products [3]. As a result, corrosion rates in atmospheric environments are smaller and cannot be directly compared to results obtained under immersion conditions.

The atmospheric corrosion progress is traditionally tracked gravimetrically by determining mass gain or mass loss of the samples after exposure. This work introduces a new method that makes it possible to monitor the real time atmospheric corrosion rate of Mg alloys during exposure. The idea is to measure the amount of hydrogen evolved during atmospheric corrosion. This is realized with an adaption of the gravimetric hydrogen collection method, originally developed by Curioni [5]. The change in buoyancy exerted by the evolved hydrogen gas can be accurately measured. Therefore, it is possible to monitor the instant atmospheric corrosion rate even at the initial stages of corrosion where mass loss measurements are difficult. Different exposure conditions like relative humidity, temperature or CO2 content can be studied. The possible contribution of the oxygen reduction reaction to the cathodic processes will be discussed.

References

[1] M. K. Kulekci, Int. J. Adv. Manuf. Technol., 39 851–865 (2008).

[2] M. Esmaily, D. B. Blücher, J. E. Svensson, M. Halvarsson, L. G. Johansson, Scr. Mater., 115 91–95 (2016).

[3] R. Lindstrom, L. G. Johansson, J. E. Svensson, Mater. Corros., 54 587–594 (2003).

[4] M. Jönsson, D. Persson, R. Gubner, J. Electrochem. Soc., 154 (11) C684–C691 (2007).

[5] M. Curioni, Electrochim. Acta, 120, 284-292 (2014).