bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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.
(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.
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.
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.
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
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.