bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) New Viable Nanomaterials for Ultrafast Batteries and Asymmetric Supercapacitors
Authors: Naoi Katsuhiko 
Published: February 2020

Hybrid/Asymmetric EESs based on the mechanism of “faradaic” or “extrinsic/intrinsic pseudocapacitive” can certainly overcome the EDLCs’ energy density limitation [3,4,5]. In light of this, K&W/TUAT group developed an original material processing technology called “ultracentrifugation (UC)” that allows to prepare (mass produce) a variety of ultrafast (Li-insertion) nanomaterials capable of 3-7 fold enhancement in energy density. It’ s been demonstrated that UC process typically under 75,000g (with subsequent heat or hydrothermal treatment) gives spinel Li4Ti5O12 nanocrystal as nanosheet/nanobook that are grown on the surface of carbon matrices like MWCNT, SGCNT [1,2,4]. The “nanohybrid capacitor(NHC)” configured as uc-LTO/LiBF4[PC] /AC tripled the energy density of conventional EDLCs [1,3,4]. Nippon Chemi-con Corp. is now eagerly developing commercial NHC device in order to place them in the market. Other uc-derived nanomaterials will be introduced together with their effective utilization in the 2nd gen. “NanoHybrid Capacitor” (JST NexTEP project, 2013-2018) and 3rd gen. “SuperRedox Capacitor” (JST A-step project, 2016-2021). As for LTO alternative anodes, b-axis (ultrashort) controlled 5-nm uc-TiO2(B) [6] and electrochemically activated uc-Li3VO4 [7], both showed ultrafast (300C) charge-storage performances. As cathode, nano-structured 2-cores/1-shell of [uc-LiFePO4(LFP)/amorphous/defective LFP/graphitic carbon] shows ultrafast and symmetric discharge and charge performance (300-480C) [8]. Finally, the author will present a perspective of the future supercapacitors’ market in the world.
References
[1] K. Naoi, Fuel Cells, 10, 825 (2010).
[2] K. Hata and S. Iijima et al, Science, 306, 1362 (2004).
[3] K. Naoi et al, Energy

& Environmental Science, 5, 9363 (2012).
[4] K. Naoi et al, Accounts

Chemical

Research, 46,1075(2013).
[5] M. Salanne, K. Naoi, and P. Simon et al, Nature Energy, 1, 16070 (2016).
[6] E. Iwama and K. Naoi et al, ACS Nano, 10(5), 5398, (2016).
[7] K. Naoi et al, Advanced Materials, 28, 6751 (2016).
[8] K. Naoi et al, Energy & Environmental Science, 9,2143 (2016).
(Invited) In Situ Monitoring of Mechanical Properties Via Multi-Length Scale Approach
Authors: Jäckel Nicolas , Gogotsi Yury , Levi Mikhael D. , Aurbach Doron , Presser Volker 
Published: February 2020

The in situ multi-length scale methodology creates new insights for the correlation of structural changes on the (sub-) nanometer scale with the resulting behavior of a bulk electrode in batteries and supercapacitors. The primary atomic-scale effect of Li-ion intercalation-induced changes of the unit cell volume or ion insertion between layered materials generates mechanical stress. [1, 2] This electrochemical process occurs during charging and discharging, meaning insertion and extraction of ions, generating a variety of secondary multiscale dimensional changes and causes a deterioration in the energy storage performance stability. [3]
A complementary approach to monitor structural changes with in situ x-ray diffraction (XRD), microscopic changes with in situ atomic force microscopy (AFM), mesoscopic changes with hydrodynamic spectroscopy via electrical quartz microbalance measurements with dissipation monitoring (EQCM-D) and macroscopic changes with electrical dilatometry (eD) was chosen. [1, 4] We combined the results of this in situ measurement techniques. By this way, it is possible to correlate structural changes on the (sub-) nanometer scale with the resulting behavior of a bulk electrode in batteries and supercapacitors. We have proved the particularly understanding of ion intercalation into two-dimensional materials and a better understanding of the related mechanisms in composite electrodes.
1. Jäckel, N., et al., Electrochemical in Situ Tracking of Volumetric Changes in Two-Dimensional Metal Carbides (MXenes) in Ionic Liquids. ACS Applied Materials & Interfaces, 2016. 8(47): p. 32089-32093.
2. Thackeray, M., Lithium-ion batteries: An unexpected conductor. Nature Materials, 2002. 1(2): p. 81-82.
3. Shpigel, N., et al., Non-Invasive In Situ Dynamic Monitoring of Elastic Properties of Composite Battery Electrodes by EQCM-D. Angewandte Chemie International Edition, 2015. 54(42): p. 12353-12356.
4. Shpigel, N., et al., In situ hydrodynamic spectroscopy for structure characterization of porous energy storage electrodes. Nature Materials, 2016. 15(5): p. 570-575.

Figure 1: Different characteristic length scales for certain in situ measurement techniques.

Figure 1
Nitrogen-Doped Carbon Catalyst for the Electrochemical Reduction of Carbon Dioxide
Authors: LIU Jianfeng , Zhang Zhenhai 
Published: February 2020

Carbon dioxide is known as the main greenhouse gas, which is enormous produced during human activities. The electrochemical reduction of carbon dioxide not only reduce the amount of CO2, also produce CO2 to CO, the intermediate for the production of some chemical and fuels. However, the electrochemical reduction process for CO2 is inhibited due to the lack of a suitable catalyst with high energy efficiency and high conversion rate.[1] The catalysts with the precious metal catalysts, such as Ag, Au, and Zn, Ni received high energy efficiency during carbon monoxide production. Some researchers utilize these metal catalysts for CO2 reduction process, and received the corresponding results.[2] However, the cost of the precious metal is another urgent issue.
In my prior work, the nitrogen-doped graphene is applied as a non-metal catalyst for oxygen reduction reaction process in aidic and alkaline media, finally exhibit high current density and mass activity.[3,4] In this work, we also heat treated carbon with the goal of doping nitrogen into carbon, and apply this nitrogen-doped carbon as catalyst for CO2 electrochemical reduction process. The nitrogen-doped carbon catalyst exhibit higher current density and higher overpotential than the corresponding carbon, that is to say, the doped nitrogen atoms play an important role for the reduction process.
[1] C. E.Tornow, M. R. Thorson, S.Ma, A. A. Gewirth, P. J. Kenis, Journal of the American Chemical Society, 134(48), 19520, (2012).
[2] A. Salehikhojin, H. R. M. Jhong, B. A. Rosen, W. Zhu, S. Ma, P. J. A. Kenis, J.phys.chem.c, 117(4), 1627, (2017).
[3] J. Liu, D. Takeshi, D. Orejon, K. Sasaki, S. M. Lyth, Journal of The Electrochemical Society, 161(4), F544, (2014).
[4] J Liu, K Sasaki, SM Lyth, ECS Transactions 58 (1), 1751 (2013)
Pourbaix Diagrams As a Root for the Simulation of Polarization Curves for Corroding Metal Surfaces
Authors: Perry Samuel C , Mauzeroll Janine 
Published: February 2020

The corrosion of metals is a much researched area thanks to its importance in the development of materials for a wide range of applications. A common means of experimental analysis of the corrosion rate of a specific metal is the recording of polarization curves and subsequent Tafel analysis. Comparison of such data with simulated examples provides useful validation of experimental data, as well as a better understanding of the specific reactions occurring at the metal surface. Many existing models require knowledge of parameters such as the exchange current density and Tafel slope, which requires the experiment to be conducted before the model is run. Here, we propose a model based around the Pourbaix diagram, where input parameters are either simply calculated from reaction schemes, or are easily accessible from thermodynamic data tables.
In this work we use Pourbaix diagrams as a means for simulating a polarization curve at a corroding iron surface. Pourbaix diagrams show the boundaries between the changing thermodynamically stable species at a metal surface in an aqueous environment as a function of the applied potential and pH. The position of these boundaries can therefore be used to model the onset of the corresponding oxidation and reduction reactions by combining the equation of the appropriate boundary line with Butler-Volmer kinetics. At the same time, the change in pH local to the metal surface is monitored by simulating the flux of protons generated during the oxidation process, and the impact of this on the corrosion potentials and rate is taken into account. This is of great importance as the corrosion rate and the corrosion product varies according to the pH at the metal surface.
In this way, we show a simple means for the simple simulation of a polarisation curve at an iron surface, which is in excellent agreement with an experimentally recorded curve under the same conditions. This same method can then be applied to more complex metal alloys such as stainless steels, by combining the Pourbaix diagrams for the appropriate alloy components. This allows the model to be used as a standalone analytical tool for the prediction of corrosion behaviour of novel alloys before they are developed, as well as for the validation of experimental data obtained from existing samples.
Figure 1: Pourbaix diagram for the iron - water system

Figure 1
Nanostructured Steel Susceptibility to Sulfide Stress Cracking
Authors: Shadravan Arash , Case Raymundo , Rumann Argie 
Published: February 2020

The susceptibility of a high strength low alloy nanostructured steel to sulfide cracking resistance (SSCC) is assessed. Notch Tensile Slow Strain Rate (NTSSRT) method is used to evaluate the threshold stress intensity values (KISSCC)). The objective is to understand the effect of the microstructure on the susceptibility to SSCC, the control condition is a conventional low alloy carbon steel with a tempered martensite micro structure.
The tests were performed in a brine with 1% NaCl buffered at pH 4.5 with H2S gas with 1% to 100% (mol %) balance N2 at room conditions. The nanostructured steel results of the KISSCC parameter are: 107 Ksi in0.5 at 1% H2S to 42 Ksi in0.5 at 100% H2S. The control condition exhibited 22 Ksi in0.5 at 100% H2S. The evaluation of the relative crack propagation energy suggest that the nanostructured ferrite grains exhibit a much lower susceptibility to SSCC than the tempered martensitic microstructure
Effect of Cr/Mo on the Protectiveness of Corrosion Scales on Carbon Steel in Sweet Medium Under Hydrodynamic Condition
Authors: Sk Mobbassar Hassan , Abdullah Aboubakr Moustafa , Ko Monika , Laycock Nick , Ingham Bridget , Ryan Mary P , Williams David E 
Published: February 2020

In combating CO2 corrosion, literature suggests specific micro-alloying (< 2 wt. %) of plain carbon steel to be the best choice in consideration of durability to cost ratio. In order to achieve optimized steel chemistry, the effects of number of alloying elements on the corrosion behaviour and protectiveness of the corrosion scale have been studied over the years. Amongst the various alloying elements, Cr has been found to be most effective. However, to date, no convincing mechanistic interpretation for the protective effect of Cr of the corrosion scale has been developed. A further question is whether a combination of alloying elements can yield superior behaviour, and if so what are the mechanistic determinants of behaviour.
In the present study, we investigated the effects of the micro-alloying of plain carbon steel with Cr and Mo on the corrosion behaviour and scale formation and protective nature in a CO2 saturated (sweet) brine (0.5 M NaCl) environment, under controlled hydrodynamic conditions (0-1000 RPM), at 80oC in a slightly acidic environment (pH 6.6). Materials were low alloy steels fabricated by incorporating small amounts of Cr (~ 1 wt. %) and/or Mo (~ 0.7 wt. %) in base plain carbon steel. Corrosion behaviour was investigated by chronoamperometric type current-transient characteristics, as well as by initial current measurement at various flow conditions under different anodic over-potentials with respect to the open circuit potential (Eoc + 20 to + 70 mV) and initial current measurement at various anodic over-potentials under low (100 RPM) and high (1000 RPM) flow conditions.
Potentiostatic current transients indicated that the presence of Cr induced an obvious decrease in the overall current flux throughout transient whilst the presence of Mo appeared to induce faster crystallization. Qualitative observation of the scale morphology using SEM indicated that the corrosion scales formed on Cr/Mo micro-alloyed steels are comparatively thinner and yet they render better protectivity and lead to faster passivation, especially under higher flow conditions (e.g. 1000 RPM). Although, in general the higher flow rates caused higher current-flux passing through the scales at the beginning of the transient, the final stage of the current transients for Cr/Mo micro-alloyed steels indicated quicker passivation at high flow rate (1000 RPM) compared to low flow rate (100 RPM). From the mechanistic perspective, we suggest that the addition of small amounts of Cr/Mo modulates the current due to dissolution of iron, as well as the current due to growth of a crystalline layer, by modifying the local environment at the steel surface, in terms of pH and degree of supersaturation. Modeling of this hypothesis is currently in progress.

Figure 1
Self-Healing of Precoated AISI 441 for Solid Oxide Fuel Cell Interconnects at Intermediate Temperatures
Authors: Berger Robert , Lundberg Mats W , Westlinder Jörgen 
Published: February 2020

Sandvik Materials Technology develops nanocoatings for SOFC stainless steel interconnects. The properties of cerium cobalt coated AISI441 (EN 1.4509) have previously been studied extensively (1-4). However, the trend in SOFC have been to decrease working temperatures from above 800°C and today commercial systems are sold that operate below 650°C. The lower operating temperature opens up new possibilities in selection of component materials. In this study we have examined precoated AISI 441 used in solid oxide fuel cell interconnects at 650°C and compared to previous studies at 800°C. The coating characteristics after different oxidation times were studied by SEM. Also, the variation of cobalt coating thickness and the development of the surface oxides were examined by SEM.
By using the double trench approach (3) samples with and without priming at 900°C for 5 hours followed by heat treatment at 650°C, were compared. These samples were also compared to the results from (3) with a sample prepared at 800°C for a total of 504 hours.
Figure 1. Mass gain of pre-coated cerium cobalt AISI441 (EN 1.4509) from cyclic oxidation at 650°C and 800°C in ambient air. The mass gains are not corrected for Cr evaporation, which shows for the 650°C as it displays flat or negative mass gains.
References

J. Froitzheim, S. Canovic, M. Nikumaa, R. Sachitanand, L.G. Johansson and J. E. Svensson J. of Power Sources, 220, 217 (2012)

J.G. Grolig, J. Froitzheim, J.E. Svensson, J. of Power Sources, 248 1007 (2014)

R. Berger, M. W. Lundberg, J. Westlinder, H. Holmberg, ECS Trans. 68 1649 (2015)

H. Falk-Windisch, J. Claquesin, M. Sattari, J.-E. Svensson, J. Froitzheim, J. of Power Sources, 343 1 (2017)

Figure 1
Structural Reliability of Cathode Contact Materials in Planar SOFCs
Authors: Karri Naveen K , Koeppel Brian J , Nguyen Ba N , Lai Kevin 
Published: February 2020

One of the key issues hindering the commercial success of solid oxide fuel cells (SOFCs) is their long term mechanical reliability. While significant progress has been made in the electrode materials development, cell and stack manufacturing technologies, as well as large-scale system level assemblies, the operating thermal gradients in the cell or stack still remains a challenge. The thermal gradients combined with mechanical loading can lead to glass seal or other ceramic component (anode, electrolyte, and cathode) failure in SOFCs. Apart from these components that can affect the stack reliability, another weakest link identified in the assembled planar stacks is the contact between electrodes and interconnects, especially on the cathode side. While these contacts not only provide the needed mechanical support for electrodes, they also provide the necessary electrical current path in the SOFC and their failure typically results in significant loss of performance. Hence, the electrode-interconnect contact strength and bond reliability is one of the key aspects of SOFC stack mechanical reliability. One way to ensure the reliability of cathode contact materials is by experiments; however, such experiments are expensive and may not be feasible for large stacks using current generation planar SOFCs. An alternative to experiments is computational modeling of contact material mechanics and bond reliability assessment based on available experimental data. The latter method though may not quantify reliability as accurately as design-specific experiments; it does provide significant insights on the contact mechanics and parameters affecting contact reliability of planar SOFCs in general.
This paper presents recent efforts on SOFC cathode contact modeling and reliability evaluations. For this work a continuum viscous sintering model was incorporated into a commercial FEA code to simulate contact paste sintering and evaluate the cathode contact reliability. The data required for the model implementation and contact reliability assessments were obtained from literature as well as experiments conducted in-house. Sensitivity studies were conducted to assess the influence of contact sintering parameters such as contact material thickness, sintering temperature, sintering pressure etc. using a generic planar SOFC design. The reliability evaluations of SOFCs were conducted at operating as well as shutdown states using commercial software based on Weibull statistics. The realistic operating temperatures of the generic stack were obtained from the in-house multi-physics code SOFC-MP. The sintering parameter sensitivity studies indicated that of all the parameters, sintering temperature has the most significant influence on the contact densification and associated stresses. The reliability evaluations indicated that cathode contact materials still require improved sintering and higher strengths to avoid failure under shutdown conditions.

Figure 1
The Role of Interlayer on the Catalytic Activity and Performance Stability of (Pr1-xNdx)2NiO4 as Cathodes for Solid Oxide Fuel Cells
Authors: Dogdibegovic Emir , Alabri Nawf Saif , Tenny Kevin , Wright Christopher J. , Hardy John S , Coyle Christopher A , Horlick Sam , Guan Wanbing , Stevenson Jeffry W , Zhou Xiao-Dong 
Published: February 2020

The use of doped ceria as an interlayer in solid oxide fuel cells (SOFCs) is ubiquitous, which provides better thermal expansion match and prevents interaction between the cathode (e.g. LSCF) and electrolyte (e.g. YSZ). However, the role of ceria interlayer on the cathode phase durability and catalytic activity remains obscure. This is particularly true in nickelate cathodes (e.g. Pr2NiO4). Here, we report that traditional Gd-doped ceria (GDC) interlayer substantially accelerates the phase transition in Pr2NiO4. Two new interlayer designs were investigated in order to circuvent the phase evolution by using (1) a thin Pr6O11 film deposited on the surface of GDC, and (2) a Pr-doped ceria interlayer. The latter design not only suppresses the phase transition, but also results in a 48% increase in cathode performance; and more importantly, it leads to a zero degradation over long-term measurements. Systemetic in situ and post analyses were carried out to understand the mechanism, by which the interlayer affects the cathode durability and activity.
This material is based upon work supported by the U.S. Department of Energy under Award Number DE-FE0023475.
Effect of Mg/Mo Ratio in Stoichiometric Sr2MgMoO6-δ (SMM) Redox-Stable Anode
Authors: Thomas Tony , Qi He , Liu Xingbo , Zondlo John W. , Sabolsky Edward M. , Hart Richard 
Published: February 2020

The state-of-the-art Ni/YSZ anode experiences a linear expansion of up to 1% when oxidized causing an irreversible microstructural change. Hence there is a need to develop redox stable anode materials with multifunctional properties like internal reforming, low temperature operation, and poison resistance. In this work, SMM, an oxygen-deficient, mixed valent perovskite has been studied to exploit its potential as a viable anode material in the SOFC application. The mixed valance of Mo (6+ and 5+) supports the electronic conductivity while losing oxygen. It also provides platform for catalytic activity for the oxidation of hydrogen and other hydrocarbon. It has been found that SMM experiences a volumetric reduction of only 0.03% in reducing atmosphere at 800oC compared to GDC and Ni/YSZ which experiences a volumetric expansion of about 0.2 and 1% respectively.
Stoichiometric SMM has a conductivity of 50 S/cm in the reducing atmosphere and with consecutive redox cycling, the conductivity decreases. Effort has been made to understand the reason for the drop in electrical conductivity with increasing redox cycling. It has been found that SMM loses Mo with time at 800oC, accounting for the drop in conductivity. To improve the electrical performance of SMM, Mg/Mo ratio in stoichiometric SMM has been varied to compensate for Mo loss and its effect on thermal stability and electrical conductivity will be discussed in this work. Above all, these compositions will be tested as an anode in an electrolyte supported SOFC and the performance data will be compared with Mo rich SMM compositions. The change in microstructure of the anode after many operating hours will be examined and discussed in this topic. Also EIS analysis of the tested cells will be discussed in this work.
Use of a Reduced Order Model (ROM) to Simulate SOFC Performance in System Models
Authors: Koeppel Brian J , Lai Canhai , Iyengar Arun K.S. , Xu Zhijie , Wang Chao , Hackett Gregory A 
Published: February 2020

Use of SOFC-based hybrid power generation systems has the potential to reduce emissions while producing electricity from conventional fossil energy sources at costs that are competitive with other technologies. The numerical models used to perform predictive design analysis and optimization of the power generation system require an accurate representation of the SOFC stack performance over a varying range of operating conditions. Detailed stack models may contain the required information necessary for design purposes, but are often too computationally expensive for use in the overall system model. However, other desirable information about the state of the stack, such as the internal temperature gradient, is generally not available from simple performance or thermodynamic models often used to represent the SOFC. Such additional information can be important in system optimization studies to preclude operation under off-design conditions that can adversely impact overall system reliability.
Response surface techniques were used with detailed SOFC stack model results to create a computationally efficient reduced order model (ROM) of the stack. A tool was developed to randomly sample selected input parameters over the expected range of interest, perform stack solutions for these sampled points using the SOFC-MP 2D software, use regression to obtain response surfaces for the stack performance and other output metrics of interest, and export the response surfaces as a ROM. The procedure is shown in Figure 1. The ROM was then successfully implemented in an Aspen Plus® system model for a natural gas fuel cell (NGFC) power system. Additional work is in progress to improve the tool’s implementation by including the fuel/oxidant recirculation loops and to better characterize the expected approximation error of the ROM. The developed modeling approach, results of the system model integration, and ongoing efforts to improve the ROM accuracy will be presented.
Figure 1. Overview of ROM Generation Procedure and Usage

Figure 1