bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiplexed Detection of Bacterial Motives and Pathogens with Near Infrared Fluorescent Nanosensors
Authors: Nissler Robert , Bader Oliver , Dohmen Maira , Walter Sebastian , Noll Christine , Selvaggio Gabriele , Groß Uwe , Kruss Sebastian
Published: July 2022

Infectious diseases are worldwide a major cause of morbidity and mortality. Fast and specific detection of pathogens such as bacteria is needed to combat these diseases. Optimal methods would be non-invasive and without extensive sample-taking/processing. Here, we developed a set of near infrared (NIR) fluorescent nanosensors and used them for remote fingerprinting of clinically important bacteria. The nanosensors are based on single-walled carbon nanotubes (SWCNTs) that fluoresce in the NIR optical tissue transparency window, which offers ultra-low background and high tissue penetration. They are chemically tailored to detect released metabolites as well as specific virulence factors (lipopolysaccharides, siderophores, DNases, proteases) and integrated into functional hydrogel arrays with 9 different sensors. These hydrogels are exposed to clinical isolates of 6 important bacteria (Staphylococcus aureus, Escherichia coli, ...) and remote (≥25 cm) NIR imaging allows to identify and distinguish bacteria. Sensors are also spectrally encoded (900 nm, 1000 nm, 1250 nm) to differentiate the two major pathogens P. aeruginosa as well as S. aureus and penetrate tissue (>5 mm). This type of multiplexing with NIR fluorescent nanosensors enables remote detection and differentiation of important pathogens and the potential for smart surfaces.
(Digital Presentation) Fabricating SERS-Active Nanofibers Covered with Au Nanoparticles for SERS Optophysiology
Authors: Zhao Xingjuan , Masson Jean-Francois , Bazuin C. Geraldine
Published: July 2022

Nanofibers as biosensors have attracted great attention due to its facile removal from the biosystem after a period of intra- or extracellular measurements and site-specific measurement among others. The application of nanofibers covered with Au nanoparticles as SERS sensor circumvents the aggregation and accumulation of Au nanoparticles in vitro or in vivo, in addition to the greater Raman enhancement of signal than on planar surface. We report here on a strategy using block copolymer brush-layer templating and ligand exchange for fabricating highly reproducible and stable SERS-active nanofibers with tip diameters down to 60 nm and covered with well-dispersed and uniformly distributed branched AuNPs, which have intrinsic hotspots favoring inherently high plasmonic sensitivity. In addition, AuNPs with tunable morphology and adjacent spacing on the nanofibers can be adjusted using an in situ growth technique, thereby enhanced SERS sensitivity was obtained due to the asymmetric structure and coupling between the adjacent AuNPs. Tunable AuNP morphologies and hence the optical characteristics of the AuNPs on the nanofibers can be easily controlled by choice of experimental parameters, particularly the growth time. Besides, finite difference time domain (FDTD) simulations were performed to gain more insight into the electric-field enhancement of AuNPs on the high-curvature substrates. Furthermore, SERS application of these nanosensors in pH sensing and Hg2+ detection is demonstrated here, offering appealing and promising candidates for real time monitoring of extra/intra-cellular species in vitro or in vivo. In addition to SERS sensing, these highly uniform nanosensors have other far-reaching implications, including medical diagnostics, therapeutics and so on.
(Invited) Dual Functional Platinum Black-modified Miniaturized Electrodes for Hydrogenperoxide Detection
Authors: Kranz Christine , Hellmann Andreas , Daboss Sven
Published: July 2022

Microelectrochemistry has a long history in the life sciences for in vivo and in vitro measurements of

e.g., pH, oxygen, and signaling molecules such as nitric oxide (NO), adenosine-5`-triphosphate (ATP),

hydrogen peroxide (H2O2) and neurotransmitters. In particular, gaining information on signaling

molecules at live cells, e.g., during and after stimulation is of significance for understanding cell

signaling. Within recent years, our research team has focused on the development of micro-sized

sensing approaches for the detection of ATP [1,2], which is considered among the most important

autocrine and paracrine signaling molecules [3]. H2O2 belongs to the group of reactive oxygen species

(ROS), which is in contrast to radical ROS rather stable. H2O2 is involved in many physiological

processes such as hypoxic signal transduction, cell differentiation and proliferation but is also involved

in mediating immune responses [4]. The effect is, among other parameters, dependent on its local

concentration and its exposure time.

Platinum black is a highly suitable electrocatalytic nanomaterial for the electrochemical detection of

H2O2 [5]. We recently demonstrated that Pt black modified microelectrodes can be used for H2O2 at

granulocytes and peripheral blood mononuclear cells from pigs [6]. Within this presentation, we will

introduce dual functional miniaturized probes that allow further miniaturization of electrochemical

sensors for biomedical applications. We will demonstrate that these probes have great potential for cell

measurements, i.e., at macrophages that produce and release ROS in response to phagocytosis or

stimulation.

References

[1] E. Hecht, A. Liedert, A. Ignatius, B. Mizaikoff, C. Kranz, Biosens. Bioelectron. 2013, 44, 27.

[2] C. Ziller, et al., ChemElectroChem 2017, 4, 864.

[3] R. Corriden, P. A. Insel, Sci. Signal. 2010, 3, 104.

[4] C. Lennicke et al., Cell Commun. Signal. 2015, 13, 39.

[5] Y. Li, C. Sella, F. Lemaitre, M.G. Collignon, L. Thouin, C. Amatore, Electroanalysis 2013, 25, 895.

[6] A. Hellmann, S. Daboss, F. Zink, C. Hartmann, P. Radermacher, C. Kranz, Electrochim. Acta 2020, 353, 30851
Carbon Fiber Microelectrode pH Sensors with Voltammetry and Field Effect Transistors
Authors: Zestos Alexander George , Cho Whirang , Rafi Harmain , Cho Seulki , Balijepalli Arvind
Published: July 2022

Graphitic carbon fiber microelectrodes (CFMEs) have been used as biosensors for the detection of biomolecules such as neurotransmitters using fast scan cyclic voltammetry (FSCV). The electrodes are relatively small (7 microns in diameter), biocompatible, have high spatiotemporal resolution, and do not generally illicit an immune response. Traditionally, CFMEs have been used to detect neurotransmitters such as dopamine, serotonin, norepinephrine, and others. The shape and position of the cyclic voltammogram (CV) is a chemical fingerprint for neurotransmitter detection with the peak oxidative current being proportional to concentration. The method is ideal for measuring fast, subsecond changes of neurotransmitters such as the phasic firing of dopaminergic neurons. Recently, the method has been expanded to measure other molecules such as metals, amino acids, peptides (including neuropeptides), hormones, proteins, neuromodulators, and other biomolecules.

In this study, we demonstrate the use of CFMEs as both FSCV sensors and field-effect transistor (FET) transducers for dynamic pH measurements. The electrochemical oxidation and reduction of functional groups on the surface of CFMEs affect their response over a physiologically relevant pH range. When measured with FET transducers, the sensitivity of the measurements over the measured pH range was found to be (101 ± 18) mV, which exceeded the Nernst value at room temperature of 59 mV by approximately 70 %. Finally, we validated the functionality of CFMEs as pH sensors with FSCV ex vivo in rat brain coronal slices with exogenously applied solutions of varying pH indicating that potential in vivo study is feasible. The sensitive, fast, biocompatible, and selective detection of pH fluctuations provides for a multitude of potential future applications such as the optimization of biomolecule measurement and measurement of pH in specific extracellular tumor microenvironments for cancer studies in addition to many others.
(Invited, Digital Presentation) Simple Electrodes for Electrochemical Sensing
Authors: Xu Guobao , Zhang Wei
Published: July 2022

Electrodes are essential for electrochemical analysis. Numerous bare electrodes and chemically modified electrodes have been utilized for electrochemical sensing. Common bare electrodes, such as platinum electrode, gold electrode and glassy carbon electrode, are relatively expensive. It requires good skills to fabricate chemically modified electrodes to get reproducible results.

In recent years, we have exploited the applications of some simple electrodes for electrochemical sensing and biosensing [1-5]. We have used stainless steel electrode for electrochemical detection and electrochemiluminescent detection of hydrogen peroxide, glucose, and the activity of glucose oxidase [1,2]. The automatic formation of passivation layer on stainless steel electrode not only results in unique electrochemical sensing performance but also avoid complex modification of electrode. We have also developed stainless steel electrode as a new driving electrode with low background for bipolar electrogenerated chemiluminescence [3]. Moreover, we have developed carbon paste electrodes as effective electrode for sensitive detection of sodium azide and cathodic electrochemiluminescence [4,5]. Finally, we have developed a wireless electrode array chip for wireless electrochemiluminescence analysis [6,7].

Acknowledgment

We are grateful for financial support from National Natural Science Foundation of China (Nos. 22004116 and 21874126).

References

[1] A. Kitte, M. N. Zafar, Y. T. Zholudov, X.i Ma, A. Nsabimana, W. Zhang, G. Xu. Anal. Chem., 2018, 90, 8680.

[2] A. Kitte, W. Gao, Y. T. Zholudov, L. Qi, A. Nsabimana, Z. Liu, G. Xu. Anal. Chem., 2017, 89, 9864.

[3] Yuan, L. Qi, T. H. Fereja, D. V. Snizhko, Z. Liu, W. Zhang, G. Xu. Electrochim. Acta, 2018, 262, 182.

[4] Li, M. Han, F. Wu, A. Nsabimana, W. Zhang, J. Li, G. Xu. Anal. Bioanal. Chem., 2018, 410, 4953.

[5] Tian, S. Han, L. Hu, Y. Yuan, J. Wang, G. Xu. Anal. Bioanal. Chem., 2013, 405, 3427.

[6] Qi, Y. Xia, W. Qi, W. Gao, F. Wu, G. Xu. Anal. Chem., 2016, 88, 1123.

[7] Qi, J. Lai, W. Gao, S. Li, S. Hanif, G. Xu. Anal. Chem., 2014, 86, 8927.
A Search for New Mesoporous Carbon Solids with Cubic Ordered Porosity
Authors: Stewart Anna , Taylor Erin E , Stadie Nicholas P.
Published: July 2022

A three-dimensional material comprised exclusively of carbon whose underlying structure lies on a triply periodic minimal surface (TPMS) is a member of the class of hypothetical carbon allotropes known as schwarzites. Such materials are highly sought-after due to their fundamental significance (the last remaining unknown crystalline allotrope of sp2-hybridized carbon) and likely interesting properties (e.g., ballistic conduction at room temperature). Other properties include a large pore volume and high surface area for gas and ion adsorption, making them a class of candidate materials for many applications such as supercapacitor electrodes and gas storage. A true schwarzite has never been synthesized, despite their predicted low energies of formation compared to fullerenes.

This research focuses on the synthesis of an interpenetrating schwarzite-like material. A hard-templating strategy has been designed to achieve this through the synthesis of a free-standing graphene foam material whose structure lies on a cubic TPMS. The specific material of interest herein requires an ordered mesoporous silicate template that carries the Ia-3d space group with an optimal pore to wall ratio. Pore and wall structure as well as composition for these materials can be optimized by changing the hydrothermal synthesis temperature, the addition of different precursors, and by varying the cationic and neutral structure-directing agents. We present our recent progress in this effort and also propose future work to achieve optimal templates for schwarzite-like materials synthesis.

Figure 1
Biphasic Solid Electrolytes with Homogeneous Li-Ion Transport Pathway Enabled By Metal-Organic Frameworks
Authors: Won Eun-Seo , Lee Jong-Won
Published: July 2022

Solid-state batteries based on nonflammable inorganic solid electrolytes provide a promising technical solution that can resolve the safety issues of current lithium-ion batteries. Biphasic solid electrolytes comprising Li7La3Zr2O12 (LLZO) garnet and polymer have been attracting significant interest for solid-state Li batteries because of their mechanical robustness and enhanced Li+ conductivity, compared to conventional polymer electrolytes. Furthermore, the hybridization allows for the fabrication of thin and large-area electrolyte membranes without the need for high-temperature sintering of LLZO. However, the non-uniform distribution of LLZO particles and polymer species in biphasic electrolytes may cause uneven Li+ conduction, which results in poor interfacial stability with electrodes during repeated charge–discharge cycling.

In this study, we report a biphasic solid electrolyte with homogeneous Li+ transport pathway achieved by a metal–organic framework (MOF) layer. To regulate and homogenize the Li+ flux across the interface between the electrolyte and electrode, a free-standing, biphasic solid electrolyte membrane is integrated with the MOF nanoparticle layer. A mixture of plastic crystal (PC) and polymeric phase is infused into porous networks of the MOF-integrated electrolyte membrane, producing the percolating Li+ conduction pathways. The MOF-integrated electrolyte membrane is found to form the smooth and uniform interface with nanoporous channels in contact with the electrodes, effectively facilitating homogeneous Li+ transport. A solid-state battery with the MOF-integrated electrolyte membrane shows the enhanced rate-capability and cycling stability in comparison to the battery with the unmodified biphasic electrolyte. This study demonstrates that the proposed electrolyte design provides an effective approach to improving the interfacial stability of biphasic electrolytes with electrodes for long-cycling solid-state batteries.

[1] H.-S. Shin, W. Jeong, M.-H. Ryu, S.W. Lee, K.-N. Jung, J.-W. Lee, Electrode-to-electrode monolithic integration for high-voltage bipolar solid-state batteries based on plastic-crystal polymer electrolyte, Chem. Eng. J, published online.

[2] T. Jiang, P. He, G. Wang, Y. Shen, C.-W. Nan, L.-Z. Fan, Solvent-free synthesis of thin, flexible, nonflammable garnet-based composite solid electrolyte for all-solid-state lithium batteries, Adv. Energy Mater. 10 (2020) 1903376.
Thermal Modeling of a Lithium-Ion Battery Module for Energy-Storage Applications
Authors: Lee Dongcheul , Kang Seohee , Kim Byungmook , Shin Chee Burm
Published: July 2022

Lithium-ion batteries (LIBs), which store electric energy and can be easy to use when power is needed, are preferred as an energy storage device to expand renewable energy use and improve the efficiency of the power industry. However, when LIBs are charged at a high rate in a low temperature, metallic lithium is deposited on an anode, which could cause safety problems due to internal short circuit. Also, when LIBs are operated at a high temperature, it promotes aging by increasing the SEI and degradation of electrode structure. Thermal management is essential for maintaining the proper temperature of LIBs for energy-storage applications. It is important to develop a thermal modeling methodology to reflect the combined effects the thermal properties of the various components of a battery cell as well as the complex structures of the battery module.

In this work, a three-dimensional modeling is carried out to investigate the effects of operating conditions on the thermal behavior of an LIB module. The battery module consisting of 28 prismatic pouch-type LIB cells fabricated by LG Chem. is modeled. The LIB cell has a nominal capacity of 63 Ah and is composed of lithium nickel manganese cobalt oxide (NMC) positive electrodes, graphite negative electrodes, and porous separators impregnated with plasticized electrolyte. In the battery module, 2 cells are connected in parallel, composing a single strand, and then 14 strands are connected in series (2P 14S configuration). The non-uniform distribution of the heat generation rate in an LIB cell within the module is calculated based the modeling results of the potential and current density distributions of the baPttery cell. Thermal modeling of an LIB module is validated by the comparison between the experimental measurements and modeling results.
(General Student Poster Session Winner - 2nd Place) Electrolysis Reference Electrode Methodology, and Electrochemical Modelling Applications
Authors: McLeod Alexander , Buehre Lena Viviane , Mérida Walter
Published: July 2022

The added constraints of fuel cells and electrolysers can make incorporating reference electrodes into their design a complex and invasive process. One set of solutions to this problem includes placing multiple reference electrodes around the perimeter to be the least invasive as possible, adding a catalyst patch to the membrane to keep potentials from fluctuating, and using additional hydrogen producing electrodes as a reference for potential [1].

The referenced approach has been proven to work in fuel cells; this work seeks to apply the referenced methodology to electrolysers, and expand upon it using electrochemical modelling techniques. By characterizing the net- and half-reactions using polarization curves and Tafel analysis at a series of different temperatures, it is possible to model the half-reaction parameters from polarization curve data collected for the net-reaction. The resulting model will then enable estimates of half-reaction parameters in a conventional two-electrode electrolyser setup.

Figure 1 shows the suggested set-up and reference electrode placement for this experiment. The reference electrodes; Re1, Re2, Re4 and Re5 will be platinized platinum wires and will work as Reversible Hydrogen Electrodes in this system. Reference electrodes ReP,0 and ReP,3 will be catalyst patches placed in chambers where the conditions will be held constant. Sensing electrodes will also be added as patches but are not subject to the same conditions as the reference electrodes. The conditions, temperature, pressure and humidity, in the cell will be known, thereby allowing for the characterization and correction of the reference electrode potentials against the Standard Hydrogen Electrode.

References:

Herrera, O. et al., “New Reference Electrode Approach for Fuel Cell Performance Evaluation” ECS Trans. Vol. 16, p. 1915, (2008)

Figure 1
Maximizing the Formate Formation of CO2 Electroreduction Via Boosting Charge Transfer Ability
Authors: Sui Peng-Fei , Xu Chenyu , Zhu Mengnan , Liu Subiao , Luo Jing-Li
Published: July 2022

The electrochemical reduction reaction of CO2 (CO2RR) is an attractive strategy for achieving carbon-neutral sustainability while the highly active and selective reaction for formate formation remains challenging. In addition, the thermodynamic inertness of CO2 usually leads to a high energy barrier for CO2RR, resulting in a preference for the competitive hydrogen evolution reaction. It is known that CO2RR is a proton-coupled electron transfer (PCET) process and the complicated multi-electron transfer steps occur on the catalyst surface. Therefore, improving the charge transfer ability is considered as an effective approach to maximizing the electrocatalytic activity and selectivity for CO2RR. Interface engineering has been proven as an effective method to prompt charge transfer by constructing interfaces within the catalysts that is widely used in many electrochemical reactions. The introduced interfaces would benefit the electronic interaction at the interface and assist the electron redistribution, thus optimizing the electronic structure and boosting the interfacial charge transfer. Herein, we report the heterostructure of Bi2S3-Bi2O3 nanosheets (BS-BO NSs) with substantial interfaces for the efficient CO2-to-formate conversion. The rapid-interfacial charge transfer induced by the abundant interfaces not only optimizes electronic structure, but also accelerates the kinetics of CO2RR and improves the electrocatalytic activity and selectivity. Compared with the separate Bi2O3 and Bi2S3 electrocatalysts, BS-BO NSs shows desirable selectivity to formate with a maximum Faradaic efficiency of 93.8 % at a moderate potential. The CO2RR performance is further boosted by using a flow cell system. The high selectivity with large current density makes BS-BO NSs a promising candidate for the practical application of CO2RR in the formate formation.
Electrochemical Versus Chemical Oxidation of 2,6-Diphenylphenol
Authors: Gao Stephanie , Martic Sanela
Published: July 2022

The phenolic compounds are used in the industry, agriculture and biotechnology, and inevitably end up in our environment. These compounds may serve as a phenolic precursor to produce raw materials for a wide range of applications. The selective electrochemical oxidation of bulky phenols was recently achieved [1]. Herein, electrochemical oxidation of 2,6-diphenylphenol (DPP) was carried out and compared to traditional chemical oxidation. Contrasted with chemical oxidation, cyclic voltammetry resulted in a range of products based on the specific potential ranges used. The electrooxidation and chemical oxidation of DPP resulted in a solution colour change and the formation of new products monitored by UV-vis, and characterized by nuclear magnetic spectroscopy (NMR), X-ray single crystal diffraction, and gas chromatography-mass spectrometry (GC-MS). Our data indicate that the synthetic outcomes are dependent on the synthetic methodology employed, and that electrooxidation may yield products which are not always possible by chemical means.

References

[1] Zabik, N. L.; Virca, C. N.; McCormick, T. M.; Martic-Milne, S. Selective Electrochemical versus Chemical Oxidation of Bulky Phenol. J. Phys. Chem. B 2016, 120 (34), 8914–8924. https://doi.org/10.1021/acs.jpcb.6b06135.

Figure 1
Hydroformylation-like Reactions Enable Electrochemical Pathways from CO2 to Extended Carbon Chains
Authors: Zeng Joy , Manthiram Karthish
Published: July 2022

Atomically precise active sites on electrode surfaces promise new chemical transformations that simultaneously exploit both the potent physical handle of applied voltage and the highly-tailored reactivity of well-defined active sites. Often, these catalysts have off-electrode analogs in biology or organometallic chemistry, and effectively leveraging these analogies requires an understanding of how catalysis at the active site is perturbed by the complex interplay of electrolyte species and electric fields at electrode interfaces. In this work, we dissect and design two atomically precise catalysts that leverage off-electrode analogies and enable an electrochemical pathway that converts CO2 to extended carbon chains.

We show that a new electrified hydroformylation reaction can be used to achieve electrochemical C-C coupling. Hydroformylation is a well-studied thermochemical reaction that performs C-C coupling by appending CO to an olefin in the presence of H2 gas. We mimic homogeneous HFN catalysts on electrode surfaces using single atom-decorated nanoparticles. We show that electrochemistry can be used to circumvent the need to supply H2 as a reactant. Instead, protons, electrons, and CO can be used to hydroformylate a model substrate. Additionally, we study the electrochemical generation of CO, a necessary reactant for hydroformylation, via immobilized cobalt phthalocyanine (CoPc) catalysts. Through collecting kinetic data over a wide range of operating conditions and quantitatively comparing candidate mechanisms, we are able to demonstrate unexpected roles of both the electrolyte and applied potential on the reaction pathway.

These studies build towards a more rigorous and quantitative understanding of how the many components of an electrode interface interact with and influence catalysis on atomically precise active sites. It is crucial to carve out this complexity if we wish to effectively import catalysts or design principles from other catalytic contexts onto electrified interfaces.
Innovative Battery Electrodes Via Composite Electroforming
Authors: Soergel Timo
Published: July 2022

Since 2012, intensive research has been conducted at Aalen University on the combination of metal foil electroforming and composite electroplating [1, 2]. At the end of 2019, the world's first pilot plant for the patented process [3] - called composite electroforming - was developed and built up as part of the BMBF project GoForE (BMBF, VIP+ funding program).

Composite electroforming can be used to produce composite metal foils with embedded functional dispersoids. The type of functional particles as well as the choice of deposition parameters makes it possible to set a specific structuring of the foil. Such structuring is particularly advantageous for battery electrodes in lithium ion and lithium-sulfur cells.

The process allows for the continuous production of novel electrode foils in form of a continuous material with a foil width of 30 cm [4-6]. The matrix material - a suitable electrodepositable metal such as nickel and aluminum - simultaneously performs the function of a current collector, binder as well as a conductive additive. Contrary to the state of the art, this allows for the first time a synergetic optimization of the mechanical and electrical bonding of the active material.

In a new approach, the metal matrix will be realized by the replacement of nickel by aluminum (BMWi, IGF project KultBat) which allows an additional boost with respect to a lowering of costs and an increase of energy and power density as well as efficiency.

The results of the meanwhile finalized GoForE project, as well as first results of the KultBat project, will be presented. In addition to the specific electroplating issues and an excursus on key figures of the produced battery cathodes, the question of process upscaleability will also be highlighted.

[1] C. Erhardt, Ş. Sörgel, S. Meinhard, T. Sörgel, J. Power Sources 2015, 296, 70-77.

[2] Ş. Sörgel, O. Kesten, A. Wengel, T. Sörgel, Energy Storage Mater. 2018, 10, 223-232.

[3] T. Sörgel, S. Meinhard, Ş. Sörgel, Film Composite Material, EP000003114721B1, 2019.

[4] T. Sörgel, ZVO report 2019, 1, 46.

[5] S. Meinhard, O. Kesten, K. Jäger, I. Hägele, T. Sörgel, Galvanotechnik 2020, 8, 1164-1169

[6] A. K. Jäger, S. Meinhard, O. Kesten, I. Hägele, T. Sörgel, WoMag 2020, 4, 25-26

Figure 1
Characterisation of Electrochemical Properties for Molten Titanium(IV) Oxide - Sodium Oxide and Expansion into Other Binary Oxide Systems for the Electrolytic Reduction of Valuable Metals
Authors: Ford Kathryn Tegan , Newport Rebecca A , Marshall Aaron Timothy , Watson Matthew J , Bishop Catherine M
Published: July 2022

Molten oxide electrolysis is a promising route to reduce harmful environmental effects that occur when compared to more common industrial metal extraction techniques. This method can provide a stepping stone to decarbonise metal production and to do this suitable supporting electrolyte ore combinations need to be found. For the application of extracting titanium metal, due to the lack of electrochemical information on complex multi-component titanium metal oxide systems, designing an electrolytic cell and predicting ultra-high temperature (above 1500°C) behaviours becomes difficult. Hence, to gain insight into this electrochemical information a binary system, TiO2 – Na2O, was investigated via experimentation and the use of FactSage 7.2 (a thermodynamic predictive software). This system was chosen as the phase diagram indicated deep eutectics either side of a congruently melting line compound situated at approximately 40 wt% TiO2, hence providing suitable operating temperature and composition ranges. Additionally, FactSage predicted that the relative potentials of the half-cell reactions 2Na2O → 4Na + O2 and TiO2 → Ti + O2, change order when the composition of TiO2 is increased from below the congruently melting line compound, to above, indicating that above approximate 40 wt% TiO2, titanium metal may be favourably reduced first when electrolytically reducing the melt. Lab scale experimental process conditions (temperature and composition) were studied to determine the feasibility of electrolytically reducing titanium metal from the molten oxide mixture. From our research, expansion into other binary oxide systems for different metals of interest, specifically neodymium and tantalum, will be discussed. Specifically, systems that contain congruently melting line compounds with adjacent eutectic reactions were hypothesised to have a similar reordering of the half-cell potentials, favouring the reduction of the desired metals (Nd or Ta). Understanding simplified binary systems will scaffold insight into more complex, industrially-relevant molten oxide mixtures at ultra-high temperatures, potentially contributing to the discovery of new and more sustainable electrochemical pathways for technology-critical metals.
Innovation Processing of Circuit Boards with FDM Printing and Selective Electrochemical Metallization
Authors: Endrikat Anna , Eggert Lara , Di Maglie Alex , Neumann Tom , Goldstein Max , Attenberger Klaus , Bouhrouch Dalal , Schlosser Michel , Bund Andreas
Published: July 2022

Additive processing like fused deposition modeling (FDM) can be used for customized products or prototypes. Due to the layer-by-layer structure it is possible to work flexibly and efficiently in geometry. In the electronics industry geometrically demanding circuit carriers can be built in relatively short times, but the processes are somewhat inflexible and take a series of processing steps. Circuit boards are made from layers of fiber-reinforced plastics and then joined by pressing. Vertical interconnects are made by copper plating. Finally, electronic components added via a soldering process.

With FDM it is possible to work flexibly with regard to geometry, printing different materials, and a large selection of filaments is given. For a circuit board, one needs at least two filament materials (one insulator, one electronic conductor) to realize conducting lines.

In this work we use FDM with different polymers for printing the substrate plate and conductor track structures in a single process. Some of the filaments are electrically conductive and can be used as conducting path structures. However, the electrical resistance of these filaments is significantly lower than conventional copper tracks. Especially for higher currents, chemical metallization of the polymer tracks with copper and tin is necessary. In the presentation we will discuss the preliminaries for achieving selective electroless metallization on selected FDM filament materials.
Introducing a Bio-Degradable Binder for Aqueous Production of NMC111 Cathodes
Authors: Bryntesen Silje Nornes , Burheim Odne Stokke , Lamb Jacob
Published: July 2022

The LiNixMn1-x-yCoyO2 (NMC) is a widely used cathode material in lithium-ion batteries (LIBs) due to its high capacity. By enabling water-based cathode processing, the cost and environmental impact of LIBs will be reduced substantially. However, the water compatibility of Ni-containing materials has been problematic due to lithium (Li)-leaching, corrosion of the aluminium (Al) current collector, and lack of aqueous dissoluble binders. For the first time, we demonstrated that NMC111 cathodes with comparable specific capacities to the standard polyvinylidene fluoride/N-methyl-2-pyrrolidone (PVDF/NMP)-processed cathodes can be formulated in water using lignin as binder material. Rheology measurements revealed that less solvent is needed to obtain the same slurry viscosity when replacing the NMP solvent with water. Cycling voltammetry and differential scanning calorimetry revealed that lignin is electrochemically inactive between 2.5-4.5 V and thermally stable up to 152 oC, respectively. Drying the cathode coatings at 50 oC allowed for a controlled evaporation rate as surface cracks and binder migration detected using scanning electron microscopy diminished. The lignin binder provided strong cohesion forces to the carbon black (CB) and the NMC111 particles, and the use of carbon(C)-coated Al-foil (C-Al) further increased the coating's mechanical strength. Scratch tests revealed that calendaring magnified the nature of the initial mechanical strength, intensifying a poor adhesion of the coating to the Al-foil and strong cohesion between the particles. While calendering and pore removal improved the rate performance for PVDF-cathodes (85:10:5 wt % NMC:CB:binder), the rate capability of lignin-cathodes (80:11:9 wt %) decreased with lower porosity (from 53 to 0 %) and higher mass loading (9.7 mg/cm2). Particle deformation and extensive pore-blocking at high carbon contents created a Li+-transfer barrier across the cathode/electrolyte surface, decreasing the rate performance. Cathodes using a CMC/lignin-binder mix (2:7 wt% ratio) and C-Al foil (75 % capacity retention) electrochemically outperformed those with the commercial CMC/SBR mix and plain Al-foil (35 % capacity retention) at a high C-rate (5 C). Of all the aqueous produced cathodes, the uncalendered with pure lignin-binder, C-Al foil, dried at 50 oC, and a mass loading of 7.4 mg/cm2 showed the highest capacity retention at 5 C (60 %). Additionally, the lignin-cathodes have poor electrolyte wetting abilities and need longer exposure time before cycling and additional formation cycles compared to the PVDF-cathodes. Lignin-cathodes with the smallest lignin/CB matrix (90:5:5 wt% NMC:CB:binder) wetted for 35 days with 5 formation cycles at C/10 showed similar initial discharge capacity and capacity retention (154 mAh/g and 89 %) as 85:10:5 PVDF-based cathodes (153 mAh/g and 93 %) after 100 cycles at C/2.
Solid State Synthesis of Aluminum Doped Li7La3Zr2O12 Garnet with Enhanced Thermal Processing Stability
Authors: Heywood Stephen , Sofie Stephen , Driscoll David
Published: July 2022

Lithium lanthanum zirconium oxide garnet (LLZO) is a solid-state lithium ion conducting electrolyte being studied extensively for all-solid-state batteries (ASSB) owing to its high lithium conductivity and chemical stability against lithium metal anodes. This material, though useful, is highly sensitive to lithium stoichiometry in terms of crystalline stability and functional properties including conductivity. Stabilizing agents such as aluminum oxide and excess lithium are needed to preserve the cubic phase and compensate for lithium volatility during high temperature processing. Material engineering that allows LLZO to be fabricated with lower sensitivity to processing conditions is an important enabler in ultimate implementation of this material.

Given the range of ceramic materials processing constraints such as ball milling, calcination, and sintering at temperatures above 1000oC, lithium volatility can drive deleterious phase formation. This study was designed to consider mechanisms that reduce the processing sensitivities of aluminum doped LLZO along its path to being utilized in a ceramic-manufacturing optimal ASSB. Processing sensitivities ameliorated via direct incorporation of excess lithium within LLZO lattice provides a key advantage towards the densification over topical additions of excess lithium precursors. By utilizing thermogravimetric analysis in conjunction with in-situ XRD analysis of solid state LLZO precursor synthesis the sensitivity of the LLZO cubic phase to lithium volatility can be reduced via early incorporation of excess lithium carbonate during initial formation. Details of in-situ phase evolution of LLZO from precursors were further clarified via temperature resolved mapping of diffraction patterns. The improved suppression of lithium volatilization has helpful implications for the scalable production of LLZO powders and assembly of ASSBs.
(Digital Presentation) Data-Driven Prognosis of Battery Failure Detection and Prediction
Authors: Liu Lin , Chandra Abhijit
Published: July 2022

Although the electric vehicle market is witnessing an unprecedented evolution, the fast adoption of these vehicles requires a more thorough status analysis of the battery performance's functionality and reliability. Due to their rechargeable nature, Lithium-ion batteries (LIBs) operation is subject to different irreversible processes during their charging and discharging cycles and causing capacity fade due to various degradation mechanisms. These processes generally result in battery capacity degradation, which usually results in battery failure, with consequences ranging from loss of operation, reduced capability, downtime, and catastrophic malfunctions. To address the issues mentioned above, numerous studies have been dedicated to proposing proper degradation model mechanisms for improving the reliability and availability of LIBs. However, due to accuracy and computational complexity challenges, most existing remaining useful life (RUL) and health prediction models focus on special degradation effects and ignore the integrated deterioration mechanisms, which generally involve batteries' capacity fade associated with the inadequacy of current health estimation tools. Thus, these shortcomings ultimately echo the need to devise novel tools to identify the dominant criteria negatively affecting battery performance and accurately predict the system's failure. The above challenges eventually necessitate a robust and reliable predictive or prognostic capability for prognostics and health monitoring (PHM) under a complexly hostile working environment. In this context, this investigation aims at proposing a novel data-driven approach called data-driven prognosis (DDP) that estimates the relevant constitutive parameters in situ and captures deviations from the expected degradation dynamics of the LIBs in addition to precise modeling of the degradation and capacity models. This talk will present a new data-driven approach using statistical pattern recognition and machine learning tools to detect batteries' anomalies and failures.
(Digital Presentation) Fabrication of Single-Crystal Layered Oxide Cathode through Variation on Heating Process
Authors: Fung Kuan-Zong , Tsai Shu-Yi , Kenneth Fung , Chang Chia-Chin
Published: July 2022

Since the announcement of a million-mile battery by Tesla, single-crystal processing of layered oxide cathode has received great attention recently. From single-crystal process, high Ni layered oxides with grain size in mm range tends to give better cycling performance due to better structural integrity against repeated charge/discharge cycles.

However, during heating/calcination process of oxide/carbonates/nitrates powder compacts, it may involve decomposition, chemical reactions, diffusion, oxidation, sintering, grain-growth. For single-crystal process, the powder compacts need to be heated to higher temperatures (~950°C) for certain period of time. On the other hand, enough air/oxygen is need for Ni oxidation and better crystallization in Ni-rich layered structure. Therefore, it is important to investigate the processing of single-crystal Ni-rich layered oxide based on the sintering behavior, thermal gravimetric analysis, and phase transformation.

Nevertheless, the lithiation/oxidation of Ni-containing oxides involves charge compensation resulted from defect reactions. As a result, the affected electrical, optical, structural, and electrochemical properties of layered oxides will be discussed based on defect chemistry consideration. The structural, microstructural and electrical properties of decomposed precursors and doped layered oxides will be examined using XRD, SEM and DC/AC impedance measurements. CV and charge/discharge tests from assembled coin cells will be used to evaluate electrochemical properties of single-crystal Ni-rich layered oxides.
(Invited) Nano Ontario - A Model for Regional Cooperation in Nanotechnology
Authors: Mascher Peter
Published: July 2022

Nano Ontario is a not-for-profit corporation representing the interests of academic, industrial, government and financial community members in the development of nanotechnologies in Ontario, Canada. Members work together to raise the profile, increase the research, build the investment and drive economic returns from nanotechnology in the province and across Canada.

In this presentation I will discuss how this multi-sector cooperation serves to achieve the following main objectives:

Be a trusted source of information for all nanoscience and nanotechnology activity in Ontario;

Advise government organizations on economic opportunity, policy, standards & regulations that nanotechnology can offer, to enable Ontario to benefit and capitalize from its nano research, development, and commercial capacity;

Map Ontario’s capacity in nanotechnology research, development, and commercialization;

Serve as the main point of contact for Ontario’s community of practice in nanoscience & nanotechnology;

Build and facilitate new connections between nanotechnology groups in universities, government organizations and industries within Ontario, across Canada, and internationally; and

Coordinate public outreach activities to advocate the societal benefits enabled by nanoscience and nanotechnology.
(Invited) Atomically Dispersed M-N-C Catalysts for Oxygen Reduction Reactions: Understanding Degradation and Improving Durability
Authors: Xie Xiaohong , Shao Yuyan
Published: July 2022

In the past decade, there has been significant progress in improving activity of atomically dispersed MN4 (M=Fe, Co, Mn, etc.) type catalysts for oxygen reduction. However, there is a significant challenge related to its poor durability. In this presentation, we will discuss our recent work on synthesizing highly active MN4 catalysts, understanding their degradation mechanisms. We will present our technical solutions to address the durability challenge.
(Invited) Impact of Pore Morphology and Surface Hydrophobicity of the Carbon Matrix on the Macrokinetics of the Oxygen Reduction Reaction Performance for Atomically Dispersed Fe-N-C Catalysts
Authors: Liu Yuanchao , Murphy Eamonn , Mamania Divija Nitin , Khedekar Kaustubh , Asset Tristan , Jaouen Frederic , Zenyuk Iryna V. , Atanassov Plamen
Published: July 2022

Atomically dispersed transition metal catalysts are an important family of non-precious metal electrocatalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells. The iron-nitrogen-carbon (Fe-N-C) catalyst, wherein the iron metal centers are coordinated by nitrogen atoms (FeNx) on carbonaceous supports, exhibits outstanding ORR activity in both rotating disk electrode (RDE) and membrane electrode assembly (MEA) configurations.[1] The pore structure[2] and surface hydrophobicity[3] of the carbon matrix are of particular significance to the MEA performance, where the high current throughput requires good mass transport capability and controlled water flooding on the electrodes. In this work, we employed two widely used Fe-N-C catalysts – one pyrolyzed from metal organic framework (MOF-derived)[4] and the other produced by using the sacrificial support method (sacrificial templated)[1]. Specifically, nitrogen physisorption and water vapor physisorption were used to study the pore morphology and the specific surface hydrophobicity, respectively. As shown in Figure 1, the sacrificial templated Fe-N-C catalyst showed a significant mesoporosity as compared to the MOF-derived counterpart, while its surface was much more hydrophobic, as indicated by the less water uptake through whole pressure range (Figure 1f). Such difference of carbon morphology was further correlated to their macrokinetic performance in a MEA configuration, to reveal the impact of the morphological and hydrophilic/hydrophobic balance on these two types of Fe-N-C catalysts.

Reference

[1] T. Asset and P. Atanassov, Joule, 2020, 4, 33.

[2] Y. Huang, Y. Chen, M. Xu, T. Asset, P. Tieu, A. Gili, D. Kulkarni, V. de Andrade, F. de Carlo, H. S. Barnard, A. Doran, D. Y. Parkinson, X. Pan, P. Atanassov, and I. Zenyuk, Materials Today, 2021, 47, 53.

[3] L. Liu, S. J. Tan, T. Horikawa, D. D. Do, D. Nicholson and J. Liu, Adv Colloid Interface Sci, 2017, 250, 64.

[4] K. Kumar, T. Asset, X. Li, Y. Liu, X. Yan, Y. Chen, M. Mermoux, X. Pan, P. Atanassov, F. Maillard and L. Dubau, ACS Catalysis, 11, 484.

Figure 1. XRD (a) and AC-STEM (b-d) images of the Fe-N-C catalyst produced by the sacrificial support method. Nitrogen (e) and water vapor (f) physisorption isotherms of MOF-derived and sacrificial templated Fe-N-C catalysts. (g) Pore size distribution of the two catalysts by the BJH method based on the N2 adsorption branch.

Figure 1
(Invited) High Energy Density and Ecofriendly Lithium-Ion Battery with Operando Monitoring
Authors: Harutyunyan Avetik R. , Kuznetsov Oleg , Chen Gugang
Published: July 2022

In addition to recent worldwide renewable energy commitments, advances in electrical vehicle technologies, flexible electronics, smart wearable devices, and internet of things, have contributed to the increasing demand for batteries with a wide range of electrochemical and electromechanical properties. In response, the battery industry has launched intensive research and development efforts in search for new materials, technologies, and concepts. However, these rapid developments give rise to a growing concern on the impact of this industry on Nature. Hence, the rapidly growing battery market demands resolutions for both energy and waste-management challenges in anticipation of about two million metric tons of annual battery waste generated globally. One way to resolve this energy and environment dilemma is by revising the conventional battery architecture to assure both high energy density and efficient recyclability aiming at circular economy. Within this strategy we fabricated self-standing composite electrodes that eliminated electrochemically inactive metal current collectors and binders from the Li-ion battery architecture, increasing energy density up to 40%. These electrodes were prepared via in situ mixing of as-grown single-wall carbon nanotubes (SWNTs) with aerosolized electrode active materials in ratios (≥0.25 wt%) that provide adequate electrical conductivity and mechanical robustness under stretching (≤15%), bending (d≥2 mm) and twisting (θ~180o) cycles. Remarkably, the resultant SWNT scaffold in composite electrodes operates as an intrinsic piezoresistive strain sensor (Gauge Factor ~6.2) that for the first time allows in situ/operando self-monitoring of battery structural health without interfering with electrochemical reactions. Moreover, the developed solution-free fabrication method eliminates hazardous, toxic, and environmentally harmful components and procedures from the electrode production line and allows their recycling by simple sonication and recovering of the active materials. In addition, the absence of current collector foils and binder allows for easy recycling and recovery of the constituent materials by using physical separation methods. These new features not only reduce consumption of the natural resources but also promote the eco-friendly circular economy for batteries.