bluuebunny/crossref_metadata_2025 huggingface dataset:
Insight into Structure and Transport of the Lithium, Sodium, Magnesium and Zinc Bis(trifluoromethansulfonyl)Imide Salts in Ionic Liquids
Authors: Borodin Oleg , Giffin Guinevere A , Moretti Arianna , Haskins Justin B , Lawson John W , Meda Lamartine , Passerini Stefano
Published: February 2020

Room temperature ionic liquids (RTILs) have attracted significant attention due to their potential applications for batteries, super-capacitors, actuators, dye sensitized solar cells and thermoelectrochemical cells. RTILs doped with lithium, sodium, magnesium and zinc salts are of primary interest for battery and hybrid capacitor applications. This presentation will focus on insights into structural and transport properties of the alkylpyrrolidinium-based ionic liquids doped with lithium, sodium, magnesium or zinc bis(trifluoromethansulfonyl)imide (TFSI) salts obtained from molecular dynamics (MD) simulations that utilized the many-body polarizable force field (APPLE&P).

After validating the ability of the developed force field to predict ionic conductivity of RTILs doped with Li, Na, Mg and Zn salts, a detailed picture of the metal coordination will be presented. The Li and Na cations were coordinated by 4.7-4.8 oxygen atoms from TFSI anions, while Zn and Mg cations were coordinated by approximately six oxygen atoms from TFSI. In addition to being primarily coordinated by TFSI oxygens, Na cations are also coordinated by fluorine and nitrogen atoms from TFSI to a larger extent than other metal cations. The representative solvates from MD simulations performed at 450 K are shown in Figure 1. The cation-TFSI bidentate vs. monodentate binding motifs and the propensity of salts to form large aggregates were analyzed as a function of temperature. Ionic conductivity, viscosity and self-diffusion coefficients from MD simulations agreed well with experimental data, where available. The cation-TFSI residence times followed the order Na< Li < Mg < Zn. Much longer cation-anion residence times for Zn and Mg compared to those of Na and Li were characteristic of the much slower dissolvation for the doubly charged cations and are expected to result in higher interfacial impedance.

This research was partially supported by NASA Minority University Research and Education Project (MUREP; NASA grant NNX15AP44A and interagency agreement NND16AA29I with ARL for modeling).

Figure 1. Representative metal solvates at 450 K and MD simulation box.

Figure 1
Investigating Barriers to Mg Intercalation in Oxide Spinel Cathodes through First-Principles Calculations
Authors: Chen Tina , Gautam Gopalakrishnan Sai , Huang Wenxuan , Ceder Gerbrand
Published: February 2020

Multivalent batteries are a promising alternative to Li-ion batteries due to their potential to provide higher energy density. Mg2+ has achieved relative success through Chevrel-structured and thio-spinel cathodes, which can be cycled against a Mg metal anode in a full-cell arrangement. However, the low voltage and capacity of the sulfide cathodes limit the energy density of this system, necessitating the search for more energy-dense Mg cathodes.1 Recent theoretical2 and experimental3 studies indicate that the oxide spinel family presents a set of promising Mg cathodes. One of these, the MgxCr2O4 spinel, has reasonable Mg migration barriers and unprecedented energy density for an intercalation cathode. Using first-principles calculations, we investigate the voltage profile for Mg insertion at room temperature and the activation barriers for Mg diffusion at different Mg concentrations in the Cr2O4 structure. Based on our results, we identify a potential limitation to Mg intercalation in the form of a stable Mg-vacancy ordering in the Cr2O4 lattice, which exhibits high migration barriers for Mg diffusion in addition to a steep voltage change. Hence, for the practical usage of Cr2O4 as a cathode in multivalent batteries, steps must be taken to avoid the formation of the stable ordered phase.

1Canepa et al, Chem. Rev. 2017, 117 (5), pp 4287-4341

2Rong et al, Chem. of Mat. 2015, 27 (17), pp 6016-6021

3 Kim et al, Adv. Mat. 2015, 27 (22), pp 3377-3384
Reaction Mechanisms of MoO2/C Nanocomposite for Sodium Ion Storage
Authors: Jiang Jiaxiang , Yang Wanli , Zhao Jianqing , Gao Lijun
Published: February 2020

Sodium ion batteries (SIBs) is considered a promising alternative candidate due to the abundant sodium resources in the earth’s crust [1]. Its working mechanism is similar to that of lithium ion batteries (LIBs), both experience intercalation and deintercalation of Li+ or Na+ into host electrode materials during charge/discharge [2]. The development of anode materials with relatively low redox potentials, high specific capacity and outstanding cycling stability is necessary to match with high performances of cathode materials, such as Na0.44MnO2 and Na3V2(PO4)3 [3]. In addition to hard carbon, which has demonstrated high performances for sodium ion storage, metal oxides as anode materials have been investigated with capability of storing sodium ion based on intercalation and conversion reactions [4]. MoO2/C nanocomposite has been studied in this work as an anode alternative for SIBs. MoO2 has low electrical resistivity (~10-5 Ω/cm in bulk sample) and high chemical stability [5], capable of reversible Na+ insertion and extraction with small volume change. However, working mechanism of MoO2 anode materials for SIBs is still far from being completely understood, and its cycleabiltiy and rate capability during sodium ion storage need to be significantly improved. In this work, our results demonstrate that nanostructured MoO2/C composite can deliver high capacity for sodium ion storage along with outstanding cycling stability and rate capability. Such a composite electrode shows intriguing mixed conversion and pseudocapacitive performances, depending on charge/discharge rates. The reaction mechanisms MoO2/C for SIB anodes will be discussed.

 References

[1] V. Palomares, P. Serras, I. Villaluenga, K.B. Hueso, J. Carretero-González, T. Rojo, Na-ion batteries, recent advances and present challenges to become low cost energy storage systems, Energy Environ. Sci. 5 (2012) 5884.

[2] S.W. Kim, D.H. Seo, X. Ma, G. Ceder, K. Kang, Electrode materials for rechargeable sodium‐ion batteries: potential alternatives to current lithium‐ion batteries, Adv. Energy Mater. 2 (2012) 710.

[3] Z. Jian, W. Han, X. Lu, H. Yang, Y.S. Hu, J. Zhou, Z. Zhou, J. Li, W. Chen, D. Chen, Superior electrochemical performance and storage mechanism of Na3V2(PO4)3 cathode for room‐temperature sodium‐ion batteries, Adv. Energy Mater. 3 (2013) 156.

[4] V.L. Chevrier, G. Ceder, Challenges for Na-ion negative electrodes, J. Electrochem. Soc. 158 (2011) A1011.

[5] X. Hu, W. Zhang, X. Liu, Y. Mei, Y. Huang, Nanostructured Mo-based electrode materials for electrochemical energy storage, Chem. Soc. Rev. 44 (2015) 2376.

Figure 1
A New Positive Electrode Material for Sodium Ion Battery
Authors: Nagao Keisuke , Takahashi Hiroo
Published: February 2020

Cost-effective and safe rechargeable batteries are required for energy storage in sustainable development. Lithium is widely used as a charge carrier of battery because the standard potential is very low. However, lithium ion battery is still too costly to use in large scale energy storages. Thus, sodium has been attracted as a substitute of lithium because the element is abundant and low-cost and its standard potential is closer to lithium.

Recently some layered materials were found out that they work as cathode materials of sodium ion batteries (SIB). The layers are composed of transition metals and oxygen, and sodium is inserted between the layers. Therefore, these materials have 2D channels of sodium. The layered materials show good capability of sodium, but the layered structure is so unstable that all inserted sodium cannot be extracted. On the other hand, some other 3D channel systems, such as phosphate systems, are enough stable to extract all inserted sodium and their effective capacity can achieve the theoretical value. [1]

In this study, we will report a novel cathode material of a sodium ion battery. We have been studying a new phosphate system material. The material shows the property as a cathode material of the SIB; reversible insertions / extractions of sodium are observed (XRD patterns are shown in Fig.1). The material has high stability on insertion and extraction of sodium ions owing to their tetrahedral structure of phosphate. In addition, by optimizing synthetic process of the material, fine particles were obtained as shown in Fig.2. Therefore the very high capacity, approximately 150 mAh/g at first cycle and over 120 mAh/g after 10 cycles, is achieved. The crystal structure of the material was analyzed precisely using atomic resolution TEM and in-situ XRD measurements with an electrochemical cell attachment. The details will be reported on the day of the session.

[1] A. Yamada, S. C. Chung and K. Hinokuma, J. Electrochem. Soc., 2001, 148, 3

Figure 1
High-Performance All-Inorganic Solid-State Sodium-Sulfur Battery
Authors: Yue Jie , Han Fudong , Fan Xiulin , Zhu Xiangyang , Ma Zhaohui , Yang Jian , Wang Chunsheng
Published: February 2020

All-inorganic solid-state sodium-sulfur batteries (ASSBs) are promising technology for stationary energy storage due to their high safety, high energy and abundant resources of both sodium and sulfur. However, current ASSB shows poor cycling and rate performances mainly due to the huge electrode/electrolyte interfacial resistance arising from the insufficient triple-phase contact among sulfur active material, ionic conductive solid electrolyte, and electronic conductive carbon. Herein, we present an innovative approach to address the interfacial problem by using Na3PS4-Na2S-C (carbon) nanocomposite as the cathode for ASSBs. Highly ionic conductive Na3PS4 contained in the nanocomposite can function as both solid electrolyte and active material (catholyte) after mixing with electronic conductive carbon, leading to an intrinsic superior electrode/electrolyte interfacial contact because only a two-phase contact is required for the charge transfer reaction. Introducing nano-sized Na2S into the nanocomposite cathode can effectively improve the capacity. The homogeneous distribution of nano-sized Na2S, Na3PS4 and carbon in the nanocomposite cathode could ensure a high mixed (ionic and electronic) conductivity and a sufficient interfacial contact. The Na3PS4-nanosized Na2S-carbon nanocomposite cathode delivered a high initial discharge capacity of 869.2 mAh g-1 at 50 mA g-1 with great cycling and rate capabilities at 60 oC, representing the best performance of ASSBs reported to date, and therefore constituting a significant step towards high-performance ASSBs for practical applications.

Reference: J. Yue, F. Han, X. Fan, X. Zhu, Z. Ma, J. Yang and C. Wang, "High-Performance All-Inorganic Solid-State Sodium-Sulfur Battery", submitted.
Chemistry and Electrochemical Performance of Inorganic Mg Electrolytes for Mg Rechargeable Batteries
Authors: Luo Jian , He Shuijian , Liu Tianbiao
Published: February 2020

The presentation will cover my group research efforts in developing high performance inorganic Mg electrolytes from MgCl2 and AlCl3 for Mg rechargeable batteries. We present unprecedented electrochemical performance of the MgCl2/AlCl3 electrolytes known to date. Chemistry and electrochemical performance of the MgCl2/AlCl3electrolytes will be discussed in detail.

References: (1) He, S.; Nielson, K. V.; Luo, J.; Liu, T. L.* Energy Storage Materials. 2017, asap (2) Liu, T.;* Shao, Y.; Li, G.; Gu, M.; Hu, J.; Xu, S.; Nie, Z.; Chen, X.; Wang, C.; Liu, J. J. Mater. Chem. A.
2014, 2, 3430. (3) Liu, T.;* Cox, J. T.; Hu, D.; Deng, X.; Hu, J.; Hu, M. Y.; Xiao, J.; Shao, Y.; Tang, K.; Liu, J. Chem. Commun.
2015, 51, 2312. (4) Filed US patent applications on Mg electrolytes (4) Group website: www.tianbiaoliu.org.
Effect of Flow Field Geometry on Operating Current Density, Capacity and Performance of Vanadium Redox Flow Battery
Authors: Maurya Sandip , Kim Yu Seung , Mukundan Rangachary
Published: February 2020

Amongst the accessible electrochemical energy storage technologies, vanadium redox flow batteries (VRFBs) are the important candidate for large-scale energy storage due to their elongated life cycle, quick response, ability to go for deep discharge, low cost, and independent energy-power outputs. To date, most of the current research has been focused on new membranes, electrodes, electrolytes and redox chemistries for better VRFB performance in terms of energy efficiencies, however, flow fields and their effects are sparsely explored. Flow fields are a crucial component in VRFB that plays vital role to distribute the electrolytes and hence significantly impacts the mass transport performance. Few flow field geometries have been studied experimentally and computationally for mass transport and pressure drop in VRFB.1–3 Nevertheless, optimal flow fields yet to be defined independently of operating conditions.4

In this research, therefore, we have studied three different flow fields: serpentine, interdigitated and flow through under the identical operating conditions. Effects of flow field geometry on operating current densities and charge/discharge capacities were evaluated. In addition, flow field effect on polarization curves have been investigated. Results show that the performance of VRFBs strongly depends on flow fields and peak power density above  500 mW/cm2 could be achieved even with thick graphite felt electrodes. The outcome of this study should be useful for researcher to further optimize VRFB system for high-performance.

Acknowledgement

This work is supported by Laboratory Directed Research & Development, Los Alamos National Laboratory.

References:

(1) Kumar, S.; Jayanti, S. J. Power Sources
2016, 307, 782–787.

(2) Xu, Q.; Zhao, T. S.; Zhang, C. Electrochimica Acta
2014, 142, 61–67.

(3) Darling, R. M.; Perry, M. L. J. Electrochem. Soc.
2014, 161 (9), A1381–A1387.

(4) Houser, J.; Clement, J.; Pezeshki, A.; Mench, M. M. J. Power Sources
2016, 302, 369–377.
Recycled Paper Derived Graphene Lithium-Sulfur Batteries with Enhanced Capacity and Extended Lifespan
Authors: Zhang Yunya , Gao Zan , Li Xiaodong
Published: February 2020

An effective strategy to tackle the twin crises of global deforestation and fossil fuel depletion is to recycle bio-mass materials for energy storage devices. Batteries have been proven to be the most effective electrochemical energy conversion and storage devices. As the most widely used battery system, lithium-ion (Li-ion) batteries have served our daily life and changed the world extensively in the past two decades. However, the potential of Li-ion battery system is approaching its limit and unable to fulfill diverse requirements. Among all possible candidates, lithium sulfur (Li-S) battery chemistry is considered to be one of the most promising next-generation, high energy density battery chemistries. The theoretical gravimetric capacity of this reaction is 1675 mAh g-1, and with the expected average voltage during discharge, the maximum energy density can be 2600 mWh g-1. However, how to build high-capacity and long-life span Li-S batteries via accessible and scalable methods is still questionable. Here we report a unique and innovative solution to capitalize on a currently overlooked resource to produce high-performance lithium-sulfur (Li-S) batteries from recycled paper. Common paper hardboard was peeled into long stripes and integrated with graphene oxide (GO) sheets by a capillary absorption method. The paper/GO hybrid was then activated at high temperature, forming activated paper carbon (APC)/graphene scaffold. The capillary absorbed GO sheets were homogeneously coated on the APC fibers and shrined geometrically during heating, forming nano sized bulges and pores, which remarkably improved sulfur loading and cathode conductivity. The recycled paper derived graphene Li-S battery exhibited superior life span of 620 cycles with an excellent capacity retention rate of 60.5%. More importantly, the APC/graphene/S stayed integral without pulverization even after such long cycling, indicating excellent mechanical robustness of cathode material. Since the malfunction of the battery can be ascribed to the anode, an activated paper carbon (APC) interlayer was sandwiched between the Li anode and the separator to suppress the degradation of Li anode by protecting the Li from unfavorable reactions, stretching the battery lifespan up to 980 cycles with a capacitance retention rate of 52.3% and improved rate ability. The capillary adsorption method and the porous anode interlayer configuration should find more applications in other porous bio-mass materials for energy storage devices.

Figure 1
Ultrathin and Conformal Metal Oxides By Atomic Layer Deposition As Coatings for Lithium Metal Batteries
Authors: Chen Lin , Elam Jeffrey W
Published: February 2020

Lithium metal has been investigated extensively recently due to its high thoretical capacity and low potential. It can also enable the unliatiated cathodes for next generation lithium batteries, such as lithium sulfur batteries and lithium air batteries. However, the uncontrolled lithium dendirtes and huge electrolyte consuption during electrochemcial cycling largely hinder its pratical use. Herein, we deposite ultrathin, conformal metal oxides (ZnO, TiO2 and MgO) by using atomic layer depostion onto lithium metal surface. The electrochemical measurements of symmetric cells and assymmetric cells will be presented for all metal oxides protected lithium. We will also show the mechansims for lithium dendrite supression behind the cycling performacne. More importantly, the charge-discharge results of lithium suflur batteries with metal oxides protected lithium will be showed.
Rechargeable Zn–Air Batteries Enabled By Zn Sponge Anodes and Bi(tri?)Functional Cathodes
Authors: Parker Joseph F. , Chervin Christopher N. , Vila Mallory , Rolison Debra R. , Long Jeffrey W.
Published: February 2020

Zinc–air batteries have the potential to overcome many of the disadvantages of current Li-ion batteries: safety concerns associated with toxic and flammable electrolytes, high costs, and specific energy <200 Wh kg–1. Zinc–air provides higher specific energy (up to 450 Wh kg–1), while using safe, low-cost components and aqueous electrolytes. Although commercially successful as a primary battery, broader implementation of Zn–air batteries is hindered by limited rechargeability and modest zinc utilization (typically <60% of theoretical discharge capacity). This long-standing performance roadblock is attributed to the manner in which Zn electrodes are commonly fabricated—by mixing Zn powder with binders and gelling agents to form composite electrodes. During discharge of these ad hoc structures, Zn is oxidized and forms soluble zincate, which diffuses from its point of electrogeneration until it supersaturates and then dehydrates to high-impedance products (e.g., ZnO). Upon electrochemical recharge, ZnO, in equilibrium with soluble zincate, is reduced back to Zn0, often accompanied by a shape change. Discharge–charge cycling leads to pronounced morphological changes, especially at points of high local current density, where short-inducing dendrites can form. We developed a Zn “sponge” form factor comprising interpenetrating, co-continuous networks of solid and void which imposes more uniform current distribution throughout the volume of the electrode structure, minimizes uneven reaction loci, and suppresses formation of dendrites. We have demonstrated that the Zn sponge electrode can be cycled in prototype Ag–Zn and Ni–Zn cells without the formation of dendrites, but translating that to the Zn–air case requires the use of air-cathodes that also support electrochemical discharge and recharge. For that more ambitious cell chemistry, we turn to powder-composite air cathodes that include mesoporous oxides of manganese and/or a solid-solution or mixed-phase oxides of transition metals such as nickel and/or iron prepared via sol–gel synthetic methods. Zinc–air cells were constructed and cycled at high depths-of-discharge relative to the Zn, an achievement that not only validates the ability for the air cathode to be bifunctionally catalyzed, but to operate at capacities and rates that turn all of the Zn in the anode over enough times to generate a technologically relevant specific energy.
(Invited) Stability of PEDOT:PSS Coating Under Electrical Stimulation – a Bench Study
Authors: Shi Alan , Braunschweig Jennifer , Scott Erik , Denison Tim , Hu Jinbo
Published: February 2020

Conductive polymers, particularly poly(3,4-ethylenedioxythiophene) (PEDOT), have attracted a good amount of interest in the past two decades as an alternative to platinum-based materials at the neural interface for electrical stimulation and recording. In addition to the reported higher charge storage and charge injection capacities, PEDOT-based coatings offer the advantages of unique physicomechanical properties, e.g., lower stiffness and a combination of electronic and ionic conductivity that could potentially create a more biomechanically compatible electrode/tissue interface.

However, questions remain in terms of the long-term physical and chemical/electrochemical stability of PEDOT:PSS and whether this or related materials can be a viable alternative to platinum alloys for long-term electrical stimulation. In this bench study, the stability of PEDOT:PSS was evaluated by subjecting coated electrodes, prepared through electropolymerization in an electrolyte containing 0.01 M of EDOT and 0.1 M of NaPSS, to biphasic constant current stimulation in 0.9% saline at 37oC. The electrode potential during stimulation was measured versus a saturated calomel reference electrode (SCE) via an integrated oscilloscope. Electrochemical impedance spectroscopy (EIS) was used as a non-destructive tool to track and assess the stability and structural integrity of the coating as a function of stimulation over time.

It was found that the anode potential and cathode potential of PEDOT:PSS coated electrodes continue to drift up in anodic and cathodic direction, respectively, under stimulation. More importantly, the Interpulse potential of the cathode can be driven into high anodic potential region that can cause irreversible physical and chemical changes to the coating that indicates a lack of stability with chronic use, which was confirmed by post stimulation visual observation and XPS surface analysis on the electrodes.
(Invited) Carbon Nanoelectrodes for Dopamine Detection and Intracellular Electroanalysis
Authors: Mirkin Michael V. , Hu Keke , Wang Dengchao
Published: February 2020

Carbon nanoelectrodes prepared by chemical vapor deposition (CVD) of carbon into the pre-pulled quartz capillaries can serve as versatile electrochemical nanosensors. We used such sensors for detection and quantitation of important analytes (e.g., dopamine) in small spaces. The applications of platinized carbon nanoelectrodes to measurement of reactive oxygen and nitrogen species in living cells are also discussed.
(Invited) Enabling Bioelectrochemistry for In Vivo Analysis
Authors: Mao Lanqun
Published: February 2020

The development of new strategies and methodologies to directly, selectively, and sensitively record chemical signals of neurons involved in brain functions has drawn more and more attention because recording of the dynamic change of chemical signals affords a platform to understanding the chemical essence involved in various brain functions, for example, neurotransmission and the diagnosis and therapy of diseases. Electrochemical methods based on bioelectrochemical mechanisms are particularly attractive for probing brain chemistry with a high temporal and spatial resolution. This topic will focus on our attempts on enabling bioelectrochemistry for in vivo analysis, covering the fundamental aspects of bioelectrochemistry with direct electron transfer of laccase as example, recent updates in biofuel cells, and new electrochemical methods for in vivo analysis based on new biosensors and biogenerators. The biogenerators are envisaged to be one kind of novel neurochemical sensing technology, providing a new tool to understanding chemical essences underlying physiological and pathological processes. With the development of the interfacial bioelectrochemistry and energy conversion technologies, some kinds of new biogenerators will be developed to work efficiently in living systems.
Development and Optimization of Capacitive Deionization for Treatment of High-Strength Agricultural Waters
Authors: Orangi Jafar , Blersch David , Davis Edward , Chen Pengyu , Beidaghi Majid
Published: February 2020

Desalination technologies are expected to play an important role in producing clean water in the future, resulting a surge in the research and development of energy efficient and cost effective technologies for desalination of seawater and brackish water. Membrane-based desalination technologies such as reverse osmosis (RO) are the most commercially used desalination methods for seawater and treatment of agricultural water, but are highly energy intensive and the future development of desalination is dependent on finding more energy efficient technologies. Capacitive deionization (CDI) is an emerging technology for water desalination, and is based on the phenomenon of ion electrosorption. Simple CDI is an energy efficient technology and its applications for desalination of low molar concentration streams, like brackish water, is demonstrated. However, to expand the applications, research is focused on improving the efficiency and salt removal capacity of CDI systems. To this end, the important requirements are finding electrode materials with higher capacities and CDI systems with higher efficiencies. Also, the large-scale application of CDI for personal and industrial applications is dependent on designing CDI systems with potential to be implemented at different capacities and length scales. In this work, we have studied the CDI for removal of salt and nutrients from agricultural water. Various high surface area electrode materials were considered and the efficiency of CDI for removal is measured via downstream analyses on batch experiments and reported, allowing development of preliminary parameters for optimizing CDI systems for high-strength agricultural wastewaters.
Nondestructive Detection of Woody Chicken Breast
Authors: Lotfi Ardalan , Navaei Milad , Hesketh Peter
Published: February 2020

The goal of this project is to develop a low cost, non-destructive system for the detection and mapping of woody from healthy tissue. Woody chicken breast is an emerging issue that affects the meat quality. While it is not harmful to humans, this issue costs the poultry industry millions of dollars in order to prevent and remove the damaged tissue. To better understand the cell composition of muscle tissue of woody and healthy samples, first the electrical properties of these samples need to be studied. Electrical characteristics of biological samples reveal significant information about the tissue compositions such as density and muscle to mass ratio qualitatively and quantitatively. Tissues (fat and mussel) are composed of cells surrounded by extracellular conductive fluid; however, the cell composition is not always uniform. In some areas cells are more occupied and the current must pass though the cell membrane. In others, cells are well separated and the current can flow. Furthermore, cells and biological components have charged particles and ions inside their cores and the surrounding medium. Therefore, the electrical properties of tissue samples would be mostly equal to its counterparts unless there is a difference in structure or density of cells inside the tissue. In order to study the electrical properties of tissue, we exploited impedance analysis technique that measures impedance of the tissue sample of interest at different range of frequencies.

To distinguish woody from healthy samples, impedance measurement was conducted in frequency ranges between 0.01 Hz to 100 KHz in order to calculate tissue resistance at high frequency and capacitance at low frequency. For this study, a set of 5 healthy and woody breast samples was used. The average resistance values of woody and healthy samples were 92 ± 8 and 303 ± 35 Ω respectively; while the average capacitances were measured to be 116 ± 14 nF and 62 ± 5 nF (woody and healthy samples respectively). As a result, impedance based detection was shown an effective method for detection of wooden breast syndrome.
(Invited) Sensors in Agriculture, Food and Research; a Biological Perspective for Engineering Food Protection
Authors: Kotewicz Michael L.
Published: February 2020

As one of six Centers in the US Food and Drug Administration, the Center for Food Safety and Applied Nutrition, CFSAN, is a regulatory agency tasked with protecting American consumers from food hazards. Case studies from food born outbreaks including diverse products such as hamburger, infant formula and flour, as well as produce including spinach, peppers and tomatoes will be discussed to illustrate the biological and food matrix considerations for engineering useful sensors. Fundamental scientific and engineering principals such as signal to noise ratios and limits of detection are balanced by economics for new technologies and will be discussed in the context of food borne pathogens including Escherichia coli, Salmonella and Cronobacter.
Multiscale Tuning of Bi- and Tri-Continuous Structures for Energy Applications
Authors: French David J , Clegg Paul S , Thijssen Job H. J.
Published: February 2020

We create bi- and tri-continuous structures by a variety of methods, including liquid-liquid phase separation and growing colloidal crystals. Liquid-liquid phase separation can be arrested using colloidal particles, which jam at the liquid-liquid interface. This creates a structure, called a bijel, where the two liquid phases and the particle layer are all continuous and interpenetrating. Bijels allow for an enormous surface area to volume ratio between the two liquids and have highly tunable mechanical properties. As they can also be post-processed, for example by replacing one of the liquids with a polymer, they are ideal templates for novel energy materials.

The bi- and tri-continuous structures we create are well-suited to applications such as electrodes in Li-air batteries, where the oxygen, electrons and electrolyte all require their own pathways.
A Novel SOFC/SOEC Sealing Glass with a Low SiO2 Content and a High Thermal Expansion Coefficient
Authors: Kiebach Ragnar , Agersted Karsten , Zielke Philipp , Ritucci Ilaria , Brock Mette Bybjerg , Hendriksen Peter Vang
Published: February 2020

Solid oxide cells require seals that can function in harsh, elevated temperature environments. In the case of solid oxide electrolysis (SOEC), also a low Si content is desired, since Si impurities from the glass sealing can be transported to the active fuel electrode and poison the Ni-YSZ triple phase boundaries.

To reduce the amount of Si emission, a low Si containing sealing glass (chemical composition: 48 mol% CaO, 19 mol% ZnO, 21 mol% B2O3 and 12 mol% SiO2) was developed at DTU. In this presentation, the results from thermal characterization, like thermal expansion coefficient, glass transition temperature, crystallization temperature, etc., of the glass will be presented. Additionally, the crystallization behavior of the glass was analyzed by in-situ X-ray diffraction, recording temperature resolved XRD spectra from 30 °C up to 900 °C.

Furthermore, the long-term stability and the adhesion behavior of the glass were studied under relevant SOFC and SOEC conditions. The stability of sealed Crofer/Glass/NiO-YSZ assemblies in reducing atmosphere and in air was investigated for over 500 h at temperatures between 750 °C and 850 °C. Additionally, a cell component test was performed to investigate the durability of the glass seal when exposed to dual atmosphere environments. The seals performed well over 400 h under fuel cell and electrolysis operation conditions, and no cell degradation or leakage related to the sealing was found, indicating that the developed glass system is applicable for the use in SOFC/SOEC stacks.
Dual Membrane Fuel Cell: From Powder to the Testing of a Two-Cells Short-Stack
Authors: Abellard André-Pierre , Chesnaud Anthony , Piccardo Paolo , Spotorno Roberto , Vladikova Daria , Stoynov Zdravko , Burdin Blagoy , Thorel Alain
Published: February 2020

A new concept of a high temperature fuel cell based on a porous dual-conducting (H+ and O2-) central membrane was successfully developed as part of a European project (“IDEAL-Cell”, FET-Energy/FP7, 2008-2011). This additional layer ensures the connectivity between both SOFC cathode/electrolyte and PCFC electrolyte/anode “water-free” compartments so that the system operates with three independent chambers. During the development of this concept, it was discovered that BCY15, used so far as a protonic conductor, exhibited a very significant anion conduction at operating temperature under oxygen atmosphere, opening up the route for a simplified and more efficient configuration; since then, BCY15 is used in all the constituent layers to lead to the so-called monolithic concept. Therefore the porous dual-conducting central membrane is made of a single BCY15 phase instead of a composite mixture of a proton conductor (i.e. BCY15) and an anion conductor (i.e. YDC15). This CM is thus sandwiched between 2 BCY15 electrolytes with a BCY15 + Ni anode on one side and a LSCF48 + BCY15 cathode on the other side. Recent works proved that electrical performances of the monolithic configuration at 600°C are higher than those measured for standard SOFCs and PCFCs at equivalent geometry.

The present work aims at presenting the first results of the manufacturing and electrochemical testing of a two-cells short stack specifically designed with 3 independent chambers in which central membrane (CM) supported monolithic cells are integrated. The supported-CMs were fabricated by using BCY15 and a polymer PMMA as a pore former agent. The CMs were sintered at 1400°C for 5 hours under static air leading to a porosity content of around 50 ± 3 vol. %. The electrolytes were then deposited onto the CMs by tape casting from an ethanol-based suspension containing BCY15 and 1 wt. % of ZnO, and were sintered at 1350°C for 3 hours. Anode ink containing 60 vol. % BCY15, 40 vol. % NiO and 10 wt. % of graphite was deposited on one electrolyte and sintered at 1350°C for 3 hours. Cathode ink containing 50 vol. % BCY15, 50 vol. % LSCF48 and 10 wt. % of graphite was deposited on the other electrolyte and sintered at 1100°C for 3 hours to avoid delamination and creeping. This processing sequence leads to flat cells having a total thickness lower than 1 mm. 2 cells were integrated in a specifically designed short stack made of INOX 440C, and sealed with Thermoculite 866 LS. The electrochemical performances of the short-stack have been measured in real operating conditions via a dedicated 3-chamber set-up named Real Life Tester (RLT), and compared to those of single cells operated under the same conditions. Results are discussed in terms of cells geometry and microstructure, and stack design improvements are proposed.
SOFC System for Battery Electric Vehicle Range Extension: Results of the First Half of the Mestrex Project
Authors: Lawlor Vincent , Reissig Michael , Makinson Julian , Rechberger Juergen
Published: February 2020

The MeStREx (Metallic Stack for Range Extender) project has being running since October 2015 and sees AVL-List GmbH (AT), Plansee GmbH (AT), Nissan (UK), Phystech Coating GmbH (AT) and the Technical University of Graz (AT) cooperate in an effort to develop an SOFC range extender system for a Battery electric vehicle. The SOFC system is specially designed for a fuel mixture containing water and ethanol. Targets for the system include 5kW Net power output, a 50% net APU efficiency and they system should deliver full power within 30 minutes. In order to reach these targets AVL-List GmbH has developed novel technological solutions that have been integrated into a test stand system. The system has been designed using a well-balanced mixture of various simulation tools and targeted experimental development. A novel start up technology has been developed that offers advantages over traditional techniques and facilitates the rapid start in a compact and efficient manner. Also, technology for reforming the fuel and water mixture has been developed and tested in close cooperation the university partners. Special metal supported stacks are being developed by Plansee that allow a rapid start and high electrical performance and efficiency. Initial results from all partners are very promising as a step towards the final goal of feasible SOFC system integration into a roadworthy vehicle. In the next step this system will be scaled in order to be integrated into a Nissan vehicle for further testing. Therefore the electrical setup and system design towards automotive standards is a key consideration and has already been intensely scrutinized.
Performance and Microstructure of a Novel Cr-Getter Material with LSCF-Based Cells in a Generic Stack Test Fixture
Authors: Chou Yeong-Shyung , Choi Jung Pyung , Stevenson Jeffry W , Liang Chiying , Hu Boxun , Rodriguez Weyshla , Aphale Ashish N , Singh Prabhakar
Published: February 2020

Cr poisoning has been identified as a leading cause for degradation of solid oxide fuel cells. Mitigation can be achieved by protective coatings such as Mn-Co spinel or aluminization on ferritic stainless steel, a leading candidate for metallic interconnect. This has been successfully demonstrated in short and medium term operation, although the long-term integrity of these coatings remains to be validated. In addition to the passive means for Cr mitigation via protective coatings, Pacific Northwest National Laboratory has teamed with University of Connecticut to adopt an active means to tackle the issue by including a novel Cr-getter material in the system. A novel Sr-Ni-oxide developed at University of Connecticut as Cr-getter has proven promising in small button cell testing. In this work, commercial YSZ/NiO anode-supported YSZ cells (50 mm x 50 mm) with either LSCF or LSM cathode were tested in a generic stack test fixture using humidified (~4.75%) air and diluted hydrogen. Two Cr-getter locations were investigated: one upstream of the cell and one “on cell.” Pre-oxidized AISI 441 metal stripes were used as the Cr source. In this study, we validated the candidate Cr-getter materials made either by a nitrate solution method or the solid-state reaction method. Candidate getter materials from nitrate solution approach were impregnated into a porous alumina form, while getter materials obtained by solid state reaction were sintered into small cylinders. For comparison, plain cells with and without a Cr source were also tested to provide baseline data. All cells were tested at constant current for ~1000h at 800oC. Cell performance and impedance were recorded, followed by post-mortem optical/electron microscopy and cathode microstructure/composition analysis. The results showed promising gettering performance with no Cr detected within cathode areas.
Preventing of LaNiO3 Formation at the LSGM-NiO Interface via LDC Protective Layer and Proper Processing Route for Solid Oxide Fuel Cells
Authors: Oncel Cinar , Gulgun Mehmet Ali
Published: February 2020

LSGM based SOFC cells are prone to suffer from performance degradation during operation, when they are used with Ni-containing anodes. In this study, one of the causes for performance degradation in an LSGM-based SOFC system was investigated. XRD and SEM studies coupled with EDX measurements revealed that formation of an insulating LaNiO3 layer is possible in such cells depending on the processing conditions. This ionic insulator phase forms a layer on the anode side of the LSGM and may block oxygen ion diffusion through electrolyte. A possible solution to hinder the formation of LaNiO3 phase is the use of doped ceria (XDC; where X = La or Sm) as a protective layer with proper processing route. Cross-sectional EDX analyses coupled with SEM showed that lanthanum doped ceria (LDC) was a very effective protection layer for LSGM. In contrast to LDC, samarium doped ceria (SDC) protective layer was ineffective. An inexpensive and feasible fabrication procedure for SOFC assembly was demonstrated with a thin (1-5 µm) and dense protective layer-electrolyte couple coated onto the anode.
Experimental Analysis on the Electrochemical Performance of Co-Electrolysis in Solid Oxide Cells Under Pressurized Operation Conditions
Authors: Yu Seongbin , Hong Jong-Eun , Lee Jong-Won , Lee Seung-Bok , Park Seok-Joo , Lim Tak-Hyoung , Song Rak-Hyun
Published: February 2020

Application of solid oxide cells to co-electrolysis of H2O and CO2 that uses an extra power derived from the renewable energy resource of solar or wind power has been attracting much attention since carbon dioxide can be reused into hydrocarbon fuels. In particular, when using a catalyst or high pressure at downstream, reactant gases of CO and H2 in the co-electrolysis can be converted to synthetic hydrocarbon fuels that are possible to be stored or transported. This study introduces the method that simplified the process of upstream and downstream in a pressurized operation system for co-electrolysis and the electrochemical performance of the cells which was dependant on operation pressure. It was confirmed that the cells could be operated at higher current densities upon increasing the operation pressure as the polarization resistance dramatically decreased.
Evaluation of Electrochemical Properties of LSCF Electrode with GDC Barrier Layer under both Fuel Cell and H2O/CO2 Co-Electrolysis Modes
Authors: Fan Hui , Zhang Yongliang , Han Minfang
Published: February 2020

Nano LSF (La0.6Sr0.4FeO3-δ)-YSZ was prepared by infiltration process for both SOFC and SOEC modes. XRD pattern and SEM characterization had demonstrated that the nano-sized LSF perovskite particles were uniformly distributed onto the inner surface of the YSZ backbone. The electrochemical performances of the cell were evaluated for both power generation and steam electrolysis, during which humidified hydrogen gas and feed gas (50%H2O+25%H2+25%N2) were introduced, respectively. Furthermore, the electrochemical stability of the cell employing the LSF-YSZ composite electrode was investigated at 0.5 A*cm-2 and 0.8 A*cm-2 for fuel cell and steam electrolysis operation, respectively. Subsequently, SEM images of the post-test cells had exhibited that the LSF-infiltrated YSZ electrodes had no obvious structural variation. The results indicated that the cell with nano-LSF-YSZ electrode had shown high long-term stability for both fuel cell and electrolysis conditions.
Probing the Cost-Effective Sodium Doped Strontium Silicate (Sr1-xNaxSiO3-0.5x) as Solid Electrolytes for IT-SOFC
Authors: Pandey Raghvendra , Singh Prabhakar
Published: February 2020

The urgency for clean and secure energy has stimulated a global resurgence in searching foradvanced electrical energy conversion systems. Solid oxide fuel cells (SOFC) have been considered as one of the most promising electro-chemical energy conversion technologies due to their high efficiency, low emission, and excellent fuel flexibility. The most widely used electrolyte materials are fluorite structured yttria stabilized zirconia (YSZ). However, use of YSZ is limited because of the limiting magnitude of the electrical conductivity and its high operating temperature over 800 °C. Recently, the sodium doped strontium silicate (Sr1-xNaxSiO3-0.5x) is gathering attentions as a fast ion conductor [1]. And Wei et al. confirmed a good SOFC performance using this electrolyte material at 500 and 600 °C [2]. In this study, we investigated this promising material to get the optimal fabrication conditions with composition and to minimize degradation problems and also enhance the stability on this material. From this study, we found out the optimal fabrication conditions (sintering at 900 °C for 10 h) for 40 % sodium doped strontium silicate electrolyte which was known as the best ionic conductor. Thermal behaviour of the compositions has also been investigated for the applicability as solid electrolyte. Moreover, for the higher doping concentration (>40 %); a decrease in the electrical conductivity is observed. This decrease in the conductivity may be due to the formation of impurity phases of sodium silicate. 

Keywords: SOFC; Electrical conductivity; solid electrolyte; strontium silicate.

References:

[1] P. Singh and J. B. Goodenough, J. Am. Chem. Soc., 2013, 135, 10149–10154

[2] T. Wei, P.Singh, Y. Gong, J.B. Goodenough, Y. Huang and K. Huang, Energy Environ. Sci., 2014, 7, 1680-1684
Enhancing Anodic Catalytic Activity at High Fuel Utilization By Infiltration of Ni Nanoparticles
Authors: Basu Soumendra Nath , Lu Yanchen , Gasper Paul Joseph , Gopalan Srikanth , Pal Uday Bhanu
Published: February 2020

The performance of SOFCs degrades with increasing fuel utilization, since the fuel oxidation reaction faces increased competition for the three-phase-boundary (TPB) sites in the anode from adsorbed water vapor species. Introduction of addition TPB sites by infiltration of Ni nanoparticles into the anode is an effective way to alleviate this problem. Both liquid and vapor phase infiltration of Ni nanoparticles into commercially available Ni/YSZ cermet anodes have been explored. The microstructure of the anode has been examined by µ-CT and FIB/SEM 3-D reconstructions. The cells have been electrochemically characterized by I-V and EIS techniques in a temperature range of 600°C-800°C. The infiltrated Ni nanoparticles have been characterized by image analysis of SEM micrographs from fracture cross-sections, before and after electrochemical testing. The effect of the nanoparticles on cell electrochemical performance as a function of temperature and anode input water vapor content, the stability of the nanoparticles, as well as the thermodynamics of vapor phase infiltration of Ni will be presented.
Enhanced Activity and Stability of Ni-Based Binary Anode in Direct NH3-Fueled SOFCs
Authors: Hashinokuchi Michihiro , Zhang Mengjia , Yokochi Ryuji , Doi Takayuki , Inaba Minoru
Published: February 2020

Ammonia (NH3) is attractive as a fuel for solid oxide fuel cells (SOFCs). NH3 is free of carbon. Furthermore, the enthalpy of NH3 reforming is low. These characters work better for SOFCs operation at intermediate-low temperature. However, the activity and long-term stability of Ni-based anodes in direct NH3-fueled SOFCs drop around 700 ˚C [1, 2]. It is necessarily to improve the anode catalyst to explore further potentials of direct NH3-fueled SOFCs.

We have studied the activity of Ni-Fe and Ni-Mo/Sm-doped CeO2(SDC) as an anode for direct NH3-fueled SOFCs at temperature of 700 to 900˚C [2, 3]. It was found that Fe and Mo enhanced the activity of the anode for NH3 oxidation (NH3 reforming, followed by hydrogen oxidation). From these results, we have proposed that the synergetic effect of Ni and Fe(Mo), which weakly and strongly bind to N atom, enhances the catalytic activity for NH3oxidation. Here, we present the activity and stability of them at low temperature.

The Ni-Fe and Ni-Mo/SDC anodes exhibited the higher activity for the electrochemical oxidation of NH3 even at temperature of 500 to 700 °C than the Ni/SDC anode. Furthermore, they exhibited the higher stability against heat cycle between 600 and 700 °C in NH3 atmosphere than the Ni/SDC anode. It was found that Fe and Mo suppressed the deformation of the anode microstructure induced by the heat cycle in NH3atmosphere. The formation of Ni-Fe and Ni-Mo alloy nitrides was confirmed in each anode. The relationship between the nitrides and the stability of the anodes are discussed.

Acknowledge

This work was supported by “Kyoto Environmental Nanotechnology Cluster” and “Kyoto Regional Scientific Innovation Hub” from MEXT in Japan.

Reference

[1] J. Yang et al., Appl. Mater. Interfaces, 7 (2015) 28701.

[2] W. Akimoto et al., Solid State Ionics, 256 (2013) 1.

[3] M. Hashinokuchi et al., Solid State Ionics, 285 (2016) 222.