bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Graphene Nanostructure By Molten Salt Process for Supercapacitor Applications
Authors: Kim Hyun-Kyung , Kumar R Vasant , Fray Derek John 
Published: February 2020

Graphene has a two-dimensional honeycomb structure consisting of a single layer of carbon atoms with a sp2-bonding configuration and has recently attracted significant attention owing to its unique properties, which include an exceptionally high specific surface area and high electrical and thermal conductivities as well as mechanical and chemical stability. However, graphene sheets exhibit an extreme tendency to agglomerate or restack. This leads to a surface that is electrochemically less effective, low electrical conductivity, and an interlayer spacing that hinders access to electrolyte ions, thus limiting the use of the sheets in supercapacitor applications. Introducing spacer materials such as metal oxide, carbonaceous between the graphene sheets is a viable strategy for preventing the sheets from agglomerating.
In this study, we report the scalable fabrication of a high-quality hierarchical interconnected carbon nanostructure, combining two-dimensional graphene nanosheets and one-dimensional graphene nanoscrolls from graphite by a simple high temperature molten salt method. The electrode using the prepared material exhibited high reversible specific capacitance, excellent rate capability, and good cyclability because of their unique interconnected networks of carbon nanostructures with high electrochemically active surface area and high electrical conductivity.
More details on the synthetic procedure, electrochemical and structural properties will be presented at the meeting.
Highly Porous N-Doped Graphitic Carbon from Bio-Waste As Bifunctional Elactrocatalyst for Hybrid Na-Air Battery
Authors: Baskar Senthilkumar , Barpanda Prabeer 
Published: February 2020

Rechargeable metal-air batteries have emerged as one of the most promising candidates for sustainable energy storage in the near future due to its high energy density [1,2]. In such a context, Lithium-air battery with a very high theoretical energy density (5200 Wh kg-1) received some very first attentions, but researchers soon realized that low Li abundance on Earth, poor cyclic stability and high operation overpotential make them not only high costs but also unrealistic in practical applications. More recently, Sodium-air batteries (Na-air) have risen as an effective alternate to Li-air batteries, given the facts that Na-air batteries are much safer and low cost. Na-air battery has several other advantages including low overpotential and high power density, arising from much higher ionic conductivity of Na-ion based solid electrolyte (e.g. Na3Zr2Si2PO12) and high solubility of discharge generated product (i.e. NaOH rather than LiOH) [3,4]. Based on cell design and electrolyte type, Na-air batteries can be classified into two major types: Non-aqueous and Aqueous (or) hybrid batteries [5]. Recent studies have shown that aqueous Na-air batteries hold some edges over non-aqueous systems, including low operation overpotential, higher rate capability, improved energy efficiency, and higher power density. Bifunctional catalysts are prominent to attain high capacity, maximum energy efficiency and long cycle-life for aqueous rechargeable Na-air batteries [6,7]. In this work, we report the synthesis of bifunctional noble metal free, highly porous N-doped graphitic carbon from bio-waste. The highly porous carbon showed higher specific surface area of 994 m2 g-1. Electrocatalytic property of the carbon based material was evaluated using linear sweep voltammetry with rotating ring disk electrode (RRDE). The N-doped graphitic carbon nanostructures showed better oxygen evolution activity compared to Pt/C catalyst. Highly porous N-doped graphitic carbon was investigated as a potential electrocatalyst for rechargeable hybrid Na-air battery for the first time. The fabricated hybrid Na-air battery with the N-doped graphitic carbon catalyst as air-cathode delivered low overpotential and its round trip energy efficiency reached above ~85 %. The hybrid Na-air battery exhibited stable cycle performance up to 20 cycles.

Acknowledgement

Author B.S. gratefully acknowledges the DST (SERB), New Delhi, India (PDF/2015/00217) for providing Fellowship.

References

[1] B. Dunn et al., Science 334(2011)928-935.
[2] J. Zhang et al., Nat. Nanotechnol. 10(2015)444-452.
[3] S. K. Das et al., J. Mater. Chem. A2(2014)12623-12629.
[4] P. G. Bruce et al., Nat. Mater., 11(2012)19-29.
[5] K. Hayashi et al., J. Electrochem. Soc., 160(2013)A1467-A1472.
[6] J-K. Kim et.al., NPG Asia Materials, 6(2014)e144.
[7] B. Senthilkumar et al., J. Power Sources, 311(2016)29-34.
Development, Manufacturing and Deployment of SOFC-Based Products at SOLIDpower
Authors: Bertoldi Massimo , Bucheli Olivier Franz , Ravagni Alberto 
Published: February 2020

SOLIDpower provides efficient commercial SOFC generators based on its proprietary low cost planar SOFC technology. The company operates pilot manufacturing plants in Germany and Italy and performs development in Australia, Italy and Switzerland. Focusing initially on the domestic and commercial micro-generation market, the installed fleet has cumulated more than 13 Million operating hours so far. More than 700 BlueGEN systems have been installed and operated, mainly in Europe. The fleet has cumulated. The company expects to exceed 1’000 installations in 2017 and has started ramp-up to a 50 MW capacity. SOLIDpower has made first demonstration installations in the United States, the UL certification is in process to expand its markets also in the Unites States of America.
SOLIDpower is also a technology company that develops new applications based on the electrochemical membrane reactor. Besides co- and poly-generators of increased power level, also applications in the field of electrolysis and hydrogen generation are part of the development portfolio. For such specific developments, SOLIDpower establishes product development partnership with the end-user or system integrator.
The field of new applications opens new challenges on the material and engineering side of the systems that go beyond the classical cost reduction and performance increase questions. A few example of challenges will be presented.
Development and Commercialization of New Residential SOFC CHP System
Authors: Yoda Masakazu , Inoue Shuichi , Takuwa Yuya , Yasuhara Kenichirou , Suzuki Minoru 
Published: February 2020

Osaka Gas began selling the new version residential SOFC CHP system “ENE-FARM type S” in April 2016, which is developed in collaboration with Osaka Gas, Aisin Seiki, Kyocera and Noritz. Kyocera manufactures SOFC stacks, Aisin Seiki manufactures power generation units, and Noritz manufactures boiler and remote-control units. The electrical efficiency is 52% (net AC, LHV), whereas that of the previous model was 46.5%.The previous system comprised two units: a power generation unit and a heat recovery unit. The latter unit contained the hot-water storage tank and the boiler. The new power generation unit contains the hot-water storage tank. This tank is configured for connection to a normal household boiler. The system size is minimized to facilitate its use as a residential CHP system. Moreover, it is possible to install the new system in a housing complex, where the available space is limited. This feature expands the market for this system because the previous model could only be installed in a single-family house.
To achieve the high electrical efficiency of 52% (net AC, LHV) and the cost reduction, three technical issues were addressed. The first was the improvement of the fuel cell performance, the second was the optimization of the fuel utilization rate, and the third was the improvement in durability. Kyocera reduced the internal electrical resistance of the fuel cell stack. In addition, a new coating technology, i.e., electropainting, which is developed by Osaka Gas and Kyocera, was used for current collectors. Consequently, both an increase in power density (reducing the number of cells) and an improvement in the electrical efficiency have been achieved. Current collectors are oxidized at a high temperature because they comprise stainless steel. Their durability has been considerably improved by the electropainting coating technology. Aisin Seiki optimized the system controls, resulting in enhanced electrical efficiency. Osaka Gas conducted field tests in the Kansai area in Japan. We installed the systems in the houses of several employees for evaluating the system behavior. The results made it possible to accelerate product development.
In accordance with the liberalization of the power market in Japan in April 2016, if customers use natural gas provided by Osaka Gas, the electrical power from the unit can be sold back to Osaka Gas. We consider that 2016 is a transition period for residential CHP from the market introduction stage to the autonomous market spread stage. We are currently focusing on achieving further developments in the technology, which will enable cost reduction and higher power generation efficiency in order to maximize the target market.
Electrode and Electrolyte Imaging in 3D: Field of View or Resolution?
Authors: Lemmens Herman , Jiao Chengge 
Published: February 2020

Fuel cells and batteries depend on the transport of ions through a porous medium. The study of the 3D structure of these porous media is not straightforward. In general, a compromise must be made between resolution (which defines the smallest pore visible) and Field of View. There are different ways to create a 3D image of the porous medium; each with specific advantages and drawbacks.
MicroCT uses the absorption of X-rays to create a 3D reconstruction. The Field of View is large enough to be representative with regard to the grain sizes (1). However, the submicron porosity is typically not well captured by microCT because of its limited resolution.
The FIBSEM technique which uses a Galium ion beam for sectioning and an electron beam for imaging has high enough resolution to resolve all porosity. However, the Field of View is typically of the order of 10 micrometer; which is not big enough to create a representative model of the pore space.
In this study we have used a plasmabeam for sectioning and an electron beam for imaging. The plasmabeam typically removes a layer of 100 nm followed by imaging by the electron beam. The material removal rate with the plasmabeam is magnitudes higher than with the Ga focused ion beam, allowing to expand the field of view to hundreds of micrometers.
A 3D reconstruction of the pore space (Field of View 100 micrometer) make it possible to calculate parameters such as the tortuosity on a representative volume.
Segmentation of the pore space is not always straightforward due to minimal grey level differences between the different phases. Also, it is not uncommon to see details from layer N+1 through the pores in layer N. This so-called pore-back effect must be taken into account otherwise the permeability will be greatly underestimated.

Cai et al, Electrochimica Acta 56 (2011) 5804–5814
Diffusion-Related SOFC Stack Degradation
Authors: Menzler Norbert H. , Beez Alexander , Grünwald Nikolas , Sebold Doris , Fang Qingping , Vaßen Robert 
Published: February 2020

Solid Oxide Fuel Cell systems for stationary applications should exhibit low degradation (<< 1%/1,000h voltage loss) to ensure long-term operation (> 40,000h). The rather high operation temperature of SOFCs (≥ 700°C) is on the one hand beneficial for oxygen conduction through the ceramic-based electrolyte, but on the other hand all diffusion-related, energetically-driven mechanisms are also increased. This counts less for gas diffusion processes but is more pronounced for solid-state diffusion (surface, bulk, grain boundary). For gas diffusion processes other parameters like gas stream, individual partial pressures and partial pressure gradients are dominating.
Within two different stack tests with four-plane short stacks and their intensive post-test characterization two varying diffusion-related degradation mechanisms have been investigated. One is a short-term (~1250h) test with two different chromium evaporation protection layers on the air side metallic interconnect and frame and the other one is a long-term endurance test (~ 35,000h). For the first stack two planes were coated with a manganese oxide layer applied by wet powder spraying (WPS) while the other two planes were coated by atmospheric plasma spraying (APS) with a manganese-cobalt-iron-spinel layer. Thus the protection layers do not only differ by coating technology but also by material. The voltage loss in the planes with WPS-coated interconnect was markedly higher than in those coated by APS. Finally it turned out that the layers microstructure plays the key role in Cr evaporation minimization. In this stack, gas-phase diffusion is dominating degradation.
In the long-term operated stack, the influence of a diffusing element from the cathodic contact layer towards and through the electrolyte has been characterized. Manganese, presumably originating from the contact layer (but it’s additionally also part of the protection layer), diffuses via solid-state diffusion and reacts while reaching reducing conditions in the fuel compartment with the zirconia-based electrolyte. This interaction forms a secondary sponge-like porous phase at the boundary electrolyte-anode. This secondary phase causes stresses and leads, after growing to big islands of some ten micrometers in diameter, to electrolyte-anode delamination and finally to complete cell failure. For the Mn-related degradation solid state diffusion has been supposed, as the electrolyte is coated by a dense thin-film diffusion barrier layer which suppresses gas diffusion.
Both results indicate that volatile elements (which could either evaporate via gas phase or diffuse via solid state diffusion) should be avoided as they can lead to severe cell, stack and system failure even after thousands of hours of high-temperature operation.
New Applications of SOFC-MGT Hybrid Power Generation System for Low-Carbon Society
Authors: Kawabata Yasuharu , Tachikawa Yuya , Taniguchi Shunsuke , Matsuzaki Yoshio , Sasaki Kazunari 
Published: February 2020

SOFC and micro gas turbine (MGT) hybrid power generation system in Fig.1 (a) is expected as a solution for energy saving and less CO2 emission. High temperature pressure swing absorption (HT-PSA) in Fig.1 (b) is also expected as an efficient method for pure O2 production.
Applying HT-PSA to the pressurized high-temperature cathode off-gas of SOFC-MGT hybrid system, we are able to obtain pure O2 more efficiently than the other conventional method.
Using obtained O2 for anode off-gas oxidation, we can easily capture CO2, which leads to effective carbon-less or negative-carbon solution. Produced O2 are also useful for efficient gasification, which leads to CO2-capture IGFC system.
In this study, we performed basic performance tests of SOFC-MGT and HT-PSA systems. Using these results, we also studied expecting performance and technical issues of proposed SOFC application systems.
Acknowledgements
This research is supported by The Japan Science and Technology Agency (JST) through its “Center of Innovation Science and Technology based Radical Innovation and Entrepreneurship Program (COI Program)" and Mitsubishi Hitachi Power Systems(MHPS) Co., Ltd.

Figure 1
Dynamics of Direct Hydrocarbon PEM Fuel Cells
Authors: Kong Eugene HyunJe , Ronney Paul D , Prakash G. K. Surya 
Published: February 2020

Hydrocarbons have 50-100 times higher energy per unit weight compared to commercially available batteries, thus harvesting only 10% of the energy from hydrocarbons could provide a far lighter energy source for portable electronic devices. With this motivation, the feasibility of using Polymer Electrolyte Membrane (PEM) fuel cells with propane fuel, operating at low temperatures (< 100˚C), was explored. Nafion® membranes were used as electrolytes and platinum black was used as catalyst. At a catalyst loading of 15 mg/cm2 at anode and 8 mg/cm2 at cathode, a maximum steady-state power density of 7.5 mW/cm2 was observed. However, with hydrazine treatment of platinum black catalyst nearly doubled the power density of propane fuel and increased power by about 50% with hydrogen fuel.
It was interesting to note that there was a significant influence of the current history on the fuel cell performance. In particular, at higher current densities (> 24 mA/cm2) the power output gradually decreases then rapidly “extinguishes” (i.e., produces no power). However, by employing an unconventional operating mode (“load-interrupt”) where the current is shut off for a short period of time and then reapplied, the maximum average power density increased to 11.6 mW/cm2. For dimethyl ether (DME) and hydrogen, no significant effect of current history was observed.
It is proposed that the fuel cell “extinction” is associated with the formation of inactive intermediate species on the anode, blocking active sites. A simple model was developed in an effort to interpret “extinction” behavior. This model assumes all sites are in either an “active” or “inactive” state with heuristic kinetic relations to describe the rates of conversion of active to inactive sites and vice versa. This model was found to be in good qualitative agreement with the experiments when the rate of formation of inactive sites was proportional not only to the number of active sites but also the number of already-inactive sites, i.e. in a self-accelerating manner. Possible physical mechanisms for this heuristic model are discussed.
Selective Ion Removal from Water Using Flow-through Electrode Capacitive Deionization (fteCDI)
Authors: Campbell Patrick G. , Hawks Steven A , Cerón Maira R. , Pham Tuan Anh , Shea Patrick , Wood Brandon C. , Stadermann Michael 
Published: February 2020

Capacitive deionization (CDI) removes ions from solution using charged electrodes. CDI has demonstrated significant energy savings compared with reverse osmosis for removal of salt from brackish water. By tailoring electrode properties such as pore morphology and surface functionality, as well as cell operating parameters, selective separation of ions can be achieved (e.g., selective absorption of nitrate in the presence of chloride and sulfate ions). The selective removal of toxic ions from otherwise potable water has the potential to dramatically reduce the cost of water treatment. Here, we will present the latest work from Lawrence Livermore National Laboratory on selective ion removal using our unique flow-through electrode CDI platform, including the development of a multi-scale model (FE + QMD) to help elucidate the mechanism(s) for ion selectivity in CDI.
This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
Alkaline Plating and Striping of Metal-Amine Complexes for Amine Regeneration in Gas Scrubbing Processes
Authors: Wang Miao , Hariharan Subrahmaniam Bharadwaj , Massen-Hane Michael Edward , Shaw Ryan , Hatton T. Alan 
Published: February 2020

Traditional thermal amine gas scrubbing technology can be energy and capital intensive owing to the enthalpy of formation of amine-CO2 complexes and the complexity in the process integration of a stripper column. An electrochemically mediated amine regeneration cycle in traditional gas scrubbing process has been proposed for post combustion CO2 capture.1
2 We take the advantage of competitive binding of amine with electroactive species, e.g. copper, to facilitate the desorption of CO2 and regeneration of amine in a modular electrochemical reactor.3 We investigated the energy efficiency of this electrochemical process via bulk electrolysis of the electrolyte. The charges applied in electrochemical metal dissolution are compared quantitatively to gas desorption in the electrolyte. Our controlled volume analysis validates the efficacy of the proposed cycle. We benchmarked the polarization of metal electrodes with different metal-amine complexes using a rotating disk electrode. The Tafel expression of the kinetic data assists in gauging the rate of metal dissolution/plating and provides insight into effects of various anions. We examined the quality of metal deposits at different operating conditions using XPS. The surface composition of the electrodes account for long-term stability of the electrodes. These thermo and kinetic data afford qualitative comparison of cell-level performance in the amine regeneration cycle.
References:

M. C. Stern, F. Simeon, H. Herzog, and T. A. Hatton, Energy Environ. Sci., 6, 2505 (2013) http://xlink.rsc.org/?DOI=c3ee41165f.

M. C. Stern and T. A. Hatton, RSC Adv., 4, 5906 (2014) http://xlink.rsc.org/?DOI=c3ra46774k.

N. Jemaa, H. J. Walls, R. D. Noble, D. E. Wedman, and C. A. Koval, AIChE J., 39, 867–875 (1993).
(Invited) Use of Discrete Liquid-Solid Contact Electrification As Ways of Self-Powered Sensing
Authors: Kim Dong Sung 
Published: February 2020

In this presentation, the concept of “discrete liquid-solid contact electrification”, which is result of sequential process of the liquid contact on the solid surface and successive detachment of contact liquid from the solid surface, is reported. After the first report on discrete liquid-solid contact electrification inside the conventional pipet tip surface, the phenomenon is deeply investigated and explored with the help of utilization on a hydrophobic surfaces, which enables easy detachment of liquid from its surface. As a result, the phenomenon can be intentionally suppressed and/or enhanced.
Recently, discrete liquid-solid contact electrification has been utilized as a fundamental operation mechanism of the self-powered sensor, which utilizes the contact electrification phenomenon with electrical induction to efficiently convert ambient mechanical energy to electrical energy. In this paper, the fabrication of the self-powered sensor utilizing discrete liquid-solid contact electrification is introduced to help its understanding.
With the fact that ordinary pipetting procedure always involves spontaneous discrete liquid-solid contact electrification resulting in generation of net electrical charges on the inner surface of the polymeric pipet tip, in this study, a concept of a smart pipet tip is newly proposed to evaluate the electrolyte concentration of the dispensed solution. The smart pipet tip possessing triboelectricity and thermoelectricity detecting modules is advantageous as it performs in situ evaluation of solution characteristics without any subsidiary solution handling process. The spontaneously generated electric signals are intensively investigated with the theoretical analyses. The proof-of-concept demonstration of the present smart pipet tip is shown for in situ prediction of morphology of nanoparticles during their synthetic reaction, which critically determines their catalytic activity. The present study would broaden the applications of discrete liquid-solid contact electrification, which is ubiquitous but previously inconspicuous in our daily life.