bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pathway Selection in Wet-Chemical Reaction for Hierarchical High Surface Nano-Ceria
Authors: Kim Hanbit , Shin Tae Ho 
Published: February 2020

Ceria has been received great attention owing to its unique optical, electrical and magnetic properties that make it valuable material for solid oxide fuel cells, chemical mechanical polishing, gas sensors, UV-adsorbents and automotive three-way catalysts. We study to find the right pathway in low-cost synthesis processing for nano-ceria with tremendous high surface reactivity and redox/thermal stability. Wet chemistry needs to be designed in fastidious details in order to obtain the nano-ceria with anticipated properties by the control of hierarchical surface structure of the nano-ceria. Each cerias we make has been showed poor repeatability resulted from the final architectures of it, albeit, it is synthesized from the same reactant concentration. It would be the thermodynamic differences of the pathways lead to crucial distinction in structure of nano-ceria depending on reaction time, the moment concentration and the temperature. The Hierarchically well-constructed nano-ceria shows high thermal stability in consequence of sufficient space to avoid the agglomerating among the crystals could maintain its structure at high temperature. Thus, to determine the relation between the pathway and result thermodynamically is one of the crucial part of design the right wet-chemical reaction, in order to get the nano-ceria with high surface reactivity and the redox/thermal stability with good repeatability. Furthermore, hierarchical high surface nano-ceria could be used for electrochemical device operating in extreme condition.

Figure 1
Synthesis of Gadolinium Doped Cerium Oxide at Low Temperature for Ion Transport Membrane
Authors: Jin Yun Ho , Song Chul-Han , Jang Dae Hwan , Yang Jae-Kyo 
Published: February 2020

Recently, Ion transport membrane (ITM) or solid oxide membrane (SOM) technologies have been developed for new metal reduction technology because traditional extraction process emitted massive CO and CO2 gas and consumed large amount of electricity. The membrane based extraction process is now a promising candidate for resolving previous problems. Using high oxide ion conductivity such as yttria-stabilized zirconia (YSZ) or gadolinium-doped cerium oxide (GDC) for solid electrolytes between the anode and liquid electrolyte.
Here we successfully were synthesized gadolinium doped ceria (GDC) below 100oC by urea-mediated routes in two steps. Gadolinium nitrate hydrates and Cerium nitrate hydrates were used as reagents. Hydrolysis reactions were induced by various concentration of Urea. The Collected powders were calcined to transform from cerium carbonate hydrates to cerium oxide at 700oC for 2 hours in air.
The GDC powders were analyzed by X-ray diffractometer (XRD) for reveal its phases. The amount of Gadolinium dopants were measured by X-ray fluorescence (XRF) and Energy dispersive X-ray spec troscopy (EDX). Scanning Electron Microscopy (SEM) and Transmission electron microscopy (TEM) were exhibits its size and morphology. Finally, its ion conductivity were measured by electrochemical impedance spectroscopy in various temperature for comparison with commercial YSZ.

Figure 1
Electrophoretically Deposited Copper Manganese Spinel Coatings for Interconnections in Solid Oxide Fuel Cells
Authors: Sun Zhihao , Gopalan Srikanth , Pal Uday Bhanu , Basu Soumendra Nath 
Published: February 2020

Chromium poisoning of the cathode due to oxidation of metallic interconnections and subsequent formation of vapor phase chromium containing species is a well-known problem. The application of ceramic coatings on the interconnections to prevent this deleterious phenomenon is currently being extensively investigated.
Copper manganese spinel coatings of different compositions were deposited on Crofer 22 APU substrates containing grooves, by electrophoretic deposition (EPD). Thermo-gravimetric measurements under oxidizing conditions at 800°C were carried out to study the effectiveness of the coatings as diffusion barriers. Special attention was paid to coating thickness variations and adhesion around corners and the vertical walls of the grooves. Chromium diffusion into the spinel coatings as well as area specific resistance of the coatings at 800°C are reported.
The Correlative Approach of 3D Imaging Techniques, Simulation and Diffusion Experiments to Explore Transport Properties in Porous Otm Support Material
Authors: Tjaden Bernhard , Brett Daniel J.L , Lane Jonathan , Shearing Paul R. 
Published: February 2020

Solid state electrochemical energy devices such as batteries, fuel cells and oxygen transport membranes (OTMs) have the potential to revolutionize distributed low-carbon power supply. However, in order to accelerate their commercialization across a range of applications, a much improved understanding of the underlying material microstructure is required.
In particular, the rate limiting step of an OTM membrane applied for syngas production is found in concentration losses caused by mass transport limitations. In this field, microstructural parameters, such as tortuosity, porosity and average pore diameter, play a vital role in characterising, comparing and evaluating porous materials. However, unlike the latter two parameters, tortuosity cannot be measured directly which is why different methods have been developed for this purpose. These differ considerably from each other in terms of calculation approach and data preparation techniques.
Here, we utilise X-ray nano computed tomography (CT) techniques to reveal the complex microstructure and resolve geometric features affecting mass transport of tubular porous support layers of OTMs to examine the relationship between the pore structure and mass transport (Figure 1). This is achieved via image based tortuosity calculation methods: a fast marching computational technique and a Laplace solver using MATLAB is employed to examine the geometrical tortuosity, and StarCCM+ and COMSOL software packages are used to model the heat flux and effective transport parameters of the porous phase, respectively.
In turn, the results are validated using diffusion cell experiments to evaluate the bulk transport properties of the same samples for different binary gas mixtures at different temperatures. Tortuosity is then extracted by applying equimolar and equimass diffusion models [1].
We conclude, that image based calculation methodologies arrive at lower tortuosity values in comparison to diffusion cell experiments (Figure 2). Even the widely used Bruggeman [2] and Maxwell relations prove to be unfit to estimate tortuosity values in the analysed microstructure. The observed difference may stem from Knudsen diffusion effects which are not accounted for in the entirety of tomography based modelling techniques. Secondly, tortuosity values extracted via diffusion cell experiments are a function of gas mixture, temperature and microstructural characteristics rather than a constant value. Consequently, care must be taken in applying purely continuum interpretations of diffusion processes in these complex porous media.

References

[1] B. Tjaden et al., Solid State Ionics, 2016.
[2] B. Tjaden et al., Curr. Opin. Chem. Eng., 2016.

Figure 1
Beyond Pretty Pictures to Useful Quantities: The Next Step in 3D Quantification of SOFC Electrodes
Authors: Tariq Farid , Yufit Vladimir , Kareh Kristina , Ruiz-Trejo Enrique , Bertei Antonio , Cohen Ed , Kishimoto Masashi , Brandon Nigel P. 
Published: February 2020

Global demands for energy storage, supply and portability has seen continual increase. Meeting these demands in a clean efficient manner will be expedited through an ability to directly image energy devices such as SOFC electrodes, in 3D, at high resolutions. Tomographic techniques allow for the 3D imaging and characterisation of complex electrode microstructures down towards tens of nanometers; which are inadequately described in 2D. The performance of the electrode is dependent on nano/micro-structure as the electrochemical reactions and transport phenomena are strongly affected by the complex porous structure. Furthermore, during processing or operation microstructural evolution may degrade electrochemical performance.
However, although many studies have utilised 3D imaging, there is a need to understand the information beyond common metrics .e.g. porosity and tortuosity and pretty pictures. Increasingly large quantities of 3D or time-resolved 3D electrode data are simultaneously acquired and yet poorly understood, simply in favour of more 3D data acquisition.
Here we use tomographic techniques (X-ray & FIBSEM) to probe the 3D SOFC electrode structure at nanometer to micrometer length scales. Advanced characterisation of particle specific attributes e.g. necks, interfaces and particle clustering within SOFC electrodes is derived; the electrode is not treated as three monolithic phases. The electrode is quantified as the interaction of particles of three phases. Micro/nano structural changes are followed to facilitate understanding the differences which occur with shape, structures and morphology at high resolution. Results reveal clustering behaviour of particles. The results are also correlated with measured experimental values to provide insight into microstructure-property relationships. We correlate models and this advanced 3D quantitative analysis. In doing so, altogether this work provides important insights for electrode design, enabling 3D optimised structures to be created and understanding sources of performance degradation.

Figure 1
Garnet Based Li-Metal Batteries
Authors: Hu Liangbing 
Published: February 2020

Metallic lithium metal is considered the “Holy Grail” for high-energy density batteries. However, using lithium metal in organic liquid electrolyte systems faces many challenges in terms of both battery performance and safety. A fundamental strategy is to develop a solid-state electrolyte (SSE) to mechanically suppress lithium dendrites and intrinsically eliminate SEI formation. Meanwhile, numerous solid-state inorganic Li+ electrolytes are being investigated to replace liquid organic LIB electrolytes and enable Li metal anode. Due to their high ion conductivity and excellent stability, Li-stuffed garnets are particularly attractive, which exhibit the most promising physical and chemical properties for SSEs. However, major challenges still exist in garnet based electrolytes, including: (1) Being either too thick with corresponding high ASR or too mechanically fragile when thin (~20 μm); (2) High temperature processing that is incompatible with most anode/cathode materials; and (3) High interfacial impedance for cell operations.
In this talk, I will discuss our recent research progress on Li metal batteries with garnet electrolytes, including:
(1) interface layer treatments to improve the wetting between Li metal anode and garnet electrolytes, and stabalize Li metal-garnet interface;
(2) Garnet nanofibers that allows the development of flexible, all solid state electrolyte.
I will also breiflydiscuss cell integrations and performance.
(Invited) Correlating Ion Transport with Structure in Interstitial Containing Oxides:Potential for New Electrolytes?
Authors: Skinner Stephen J. 
Published: February 2020

Development of oxide ion conducting devices such as sensors, fuel cells and permeation membranes, has traditionally relied on the optimisation of materials with lattice vacancies through substitution, increasing the vacancy content and consequently conductivity. Whilst the ionic conductivity is a key parameter it is also essential to understand the surface exchange kinetics, stability and compatibility with other functional components. For many of the perovskite and fluorite based ion conductors the process of increasing vacancy content through substitution induces chemical instabilities, including cation segregation, that leads to reactivity and ultimately degradation in lifetime. In an effort to address some of these issues and to extend the compositional space available to materials developers we have considered the use of materials with inherent oxygen interstitial content.
A range of materials have been considered, mainly based on the scheelite framework, in which significant interstitial content can be accomodated. Two main series of oxide niobates are the subject of this study: CeNbO4+d and LaNbO4. In the first series of oxides the oxidation of the Ce3+ species on increasing temperature induces ordering and results in a fast ion transport pathway through these phases. Unusually these materials are also structurally modulated, and anisotropic in nature. The oxidation of the Ce species also induces electronic transport. Substitution of the Ce species with divalent cations did not significantly affect the ion transport. For the second series of oxides we have focused on hexavalent substitution of the Nb site to incorporate interstitials, modulate the structure and reduce the electronic transport.
Here we will discuss the potential of these modulated scheelite oxides as ion conductors, demonstrate effective electrolyte performance and correlate the ion transport with the structure of the materials, using a suite of advanced characterisation techniques.
(Invited) Advanced Electrolytes for Lithium Metal Electrode
Authors: Lee Hoogil , Jeon Hyunkyu , Ryou Myung-Hyun , Lee Yong Min 
Published: February 2020

Advanced electrolyte containing functional additives as well as dissolved lithium salts in organic solvents has greatly upgraded the performance and reliability of lithium-ion batteries (LIBs). For example, a small amount of vinylene carbonate (VC) or fluoroethylene carbonate(FEC) is still indespensable to state-of-the-art LIBs to control solid electrolyte interphase (SEI) upon graphitic carbon anodes. However, due to the energy density limitation of conventional LIBs, post LIBs having lithium metal anodes have been extensively investigated for lithium metal secondary batteries, Li/S, Li/Air, etc. during the last ten years. But, without controlling lithium dendrite formation, post LIBs may end in an empty talk. Thus, there are a variety of previous works to suppress the lithium dendrite formation by placing organic/inorganic protection layers upon lithium metal, modifying the surface morphology, or adding some functional additives. In particular, since the last approach is the most facinating method owing to simplicity, we cannot help finding new additives for electrolytes. Herein, we intoduce recent researches on advanced electrolytes for lithium metal electrode first. And then, we apply a few good candidates to micropatterned lithium metals, which could deliver much more stable cycling performance than bare ones. Finally, some optimized advanced electrolyte and micropatterned lithium metal systems are proposed in more detail.
A New Technique for Measuring the Diffusion Coefficient of Electrolytes for Lithium-Ion Batteries
Authors: Schoenleber Michael , Weber André , Ivers-Tiffée Ellen 
Published: February 2020

The electrolyte is a crucial component in modern Lithium-Ion batteries. It is responsible for the transport Lithium-Ions not only through the separator but also within the porous structure of the electrodes. A small diffusion coefficient of the electrolyte leads to an increased voltage drop due to depletion of Lithium-Ions and thus limits the performance of a battery for high currents. While the diffusion coefficient is mostly measured by potentiostatic or galvanostatic intermittent titration techniques (PITT or GITT), also an evaluation of the diffusion impedance of the electrolyte should yield according values. However, standard impedance measurement techniques like Electrochemical Impedance Spectroscopy (EIS) suffer severe disadvantages: Due to the sinusoidal excitation a current is permanently flowing and, in case of beneficially used metallic Lithium electrodes, Lithium is continuously being deposited and stripped. This causes a continuously changing surface area during the measurement and hence a time-variant and thus invalid impedance spectrum. Moreover, the diffusion impedance needs to be measured down to very low frequencies, which results in very long measurement times for regular Electrochemical Impedance Spectroscopy. As an adequate solution for both issues we suggest computing the diffusion impedance from time-domain measurements [1]: By choosing an appropriate excitation signal, changes within the system during measurement can be prevented and, as all frequencies are excited simultaneously, measurement time can be minimized. By experimentally shifting the diffusion process to lower frequencies we are further able to clearly separate it from other, surface reaction related processes and thus to isolate the diffusion impedance. For an example see Figure 1, where repeated measurements of the diffusion impedance of LiPF6 in EC/DMC (1:1) are shown. From the time constant of the diffusion impedance, the diffusion coefficient of the electrolyte is finally obtained.
Caption Figure 1:
Repeated measurement of the diffusion impedance of LiPF6 in EC/DMC (1:1), as it is commonly used in Lithium-Ion batteries (real-parts shifted to origin).
References:
[1] D. Klotz, M. Schönleber, J. P. Schmidt and E. Ivers-Tiffée, "New approach for the calculation of impedance spectra out of time domain data", Electrochimica Acta 56, pp. 8763-8769 (2011)

Figure 1
Electrochemical Characterization and Interfacial Chemistry of Tin-Based Anode Materials for Mg-Ion Batteries
Authors: Nguyen Dan Thien , Tran Xuan Minh , Song Seung-Wan 
Published: February 2020

Magnesium-ion batteries have received a particular attention as one of the beyond-lithium ion batteries for next-generation energy storage system applications. Magnesium is earth abundant and low cost compared to lithium, and environment-friendly, and provides higher theoretical volumetric capacity (3833 mAhcm-3) than lithium.1 The use of magnesium metal anode is often limited due to the formation of surface blocking layer in conventional electrolyte such as magnesium salts (TFSI-, ClO4
-, BH4
-) in ether-based solvents. To overcome these problems, recently insertion-type materials such as Sn, Sb, Pb and Bi, which is based on the alloy reaction with magnesium, have been proposed as a new class of anode materials for magnesium-ion batteries.2,3 However, studies on the materials’ intrinsic electrochemical characteristics and the interfacial chemistry between alloy anode and electrolyte are yet to be reported.
In the present study, we have investigated on the electrochemical and interfacial reaction behavior of tin-based anode materials in magnesium cells. Changes with cycling in their structure, surface property and particle morphology would be discussed in the meeting.

Acknowledgements

This work was supported by National Research Foundation of Korea (2015062107).

References

1. D. Aurbach, Z. Lu, A. Schechter, Y. Gofer, H. Gizbar, R. Turgeman, Y. Cohen, M. Moshkovich and E. Levi, Nature, 407, 724 (2000).
2. N. Singh, T. S. Arthur, C. Ling, M. Matsui, and F. Mizuno, Chem. Commun. , 49, 149 (2013).
3. F. Murgia, L. Stievano, L. Monconduit, and R. Berthelot, J. Mater. Chem. A,

3, 16478 (2015).
Preferentially Ordered Solid Electrolytes for Fuel Cell and Lithium Battery
Authors: Fang Yu-shin , Wang Robin Chih-Hsing , Chang Alice Yi-han , Chu Peter Po-Jen 
Published: February 2020

Electric field induces temporary polarization on molecular segment. In polymer solution or polymer melt, applying electric field induces self assembly that cannot be established otherwise. This preferentially ordered morphology is preserved after drying out solvent to form polymer membrane. The ordered nano structure delivered favorable ion transport behavior, raised ion conductivity, and improved membrane mechanical properties.
In one example given for fuel cell membrane composed of poly(ether sulfones)(PES) with sulfonated poly(ether ether ketone)(sPEEK, degree of sulfonation=50%) prepared with e-field poling, extremely high ion conductivity (7.43x10-2 S/cm) is observed. The hydrophilic dimension is found to be reduced which restricted methanol permeability (3.17x10-7 cm2/s). Due to more densely packed hydrophobic domain, membrane mechanical property is also improved. DMFC power output at 150mA/cm2 (80 oC, 1M Methanol) can be realized.
A second example is given for lithium battery membrane: Poly(vinylidenefluoride-co-hexafluoropylene)[PVDF-HFP] blending either with PMMA polymer, or with surface functionalized mineral clay containing ionic liquids. E-field has improved PVDF and PMMA miscibility, gave rise to more organized and more polar beta crystallite formation with denser amorphous region. The clay is homogeneously dispersed and oriented to form ordered and preferentially aligned nanostructure. As a result, the solvent free membrane delivered Li+ conductivity surpassing 10-3 S/cm at room temperature, and shows reduced interface resistance between electrodes. Coin cell (R2032) using this SPEs and LiFePO4cathode displayed 140 mAh/g discharge capacity and stable over 300 cycles, with 0.5C rate.
Membrane bearing preferentially ordered morphology induced by E-field is able to balanced high ion conductivity; low fuel/gas permeation and strong mechanical strength, simultaneously. This approach in preparing high performance membrane holds great promises to apply to future energy devices such as Li-S, Li-Air, and thin film battery.
Nanohybrid Polymer Electrolytes with Enhanced Safety and Electrochemical Performance
Authors: Wei Weifeng , Zhang Jinfang , Ma Cheng 
Published: February 2020

Rechargeable Li/Na-ion batteries have been studied extensively for the electric and energy industries, but currently used liquid electrolytes have serious safety risks (combustion and explosion). Besides, nonuniform ion (Li+/Na+) deposition on the negative electrode upon cycling would eventually cause the cell to fail. Hence, the development of safe, stable, and long-life Li/Na-ion batteries is being intensively pursued to enable high-energy-density storage system applications. Solid polymer electrolyte (SPE) is attracting considerable attention to handle potential safety risk and regarded as a safer alternative to satisfy the needs for high-performance batteries. However, low conductivities and insufficient electrode-electrolyte interfaces still hinder the potential applications of SPEs.
Here we have been targeting poly(ethylene glycol) methyl ether methacrylate (PEGMEM) and devoted a large amount of research to modifying the polymer matrix, including copolymerization of PEGMEM and SMA (stearyl methacrylate), OV-POSS based graft polymer electrolyte with star-shaped structure and construction of cross-linked branching nanohybrid polymer electrolyte by functionalized nanoparticles with polymer chains. We focus on the exploring the interfacial design to enhance interaction between nanoparticles and the polymer matrix, and utilize microscopic and spectroscopic analyses to better understand the interfacial chemistry between particles and polymeric chains.