bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elastoplastic Properties of (Pr, Ce)O2-δ
Thin Films
Authors: Swallow Jessica G. , Kim Jae Jin , Bishop Sean R. , Smith James F. , Tuller Harry L. , Van Vliet Krystyn J. 
Published: February 2020

Solid oxide fuel cells (SOFCs) rely on long term, consistent operation of non-stoichiometric oxide components under elevated temperatures and oxygen partial pressure gradients. Materials that exhibit the desired ion transport and reactivity properties generally also exhibit electro-chemo-mechanical coupling that can affect mechanical stability in operando. The importance of chemomechanical coupling such as chemical expansion of SOFC electrodes is increasingly relevant to the goal of reduced operating temperatures enabled by thin film electrodes. Here, we explore this coupling experimentally and computationally, for the model SOFC cathode material, (Pr, Ce)O2-δ. We quantified the Young’s elastic modulus E of (Pr, Ce)O2-δ thin films at temperatures up to 600ºC and oxygen partial pressures pO2 below 10-3 atm via environmentally controlled nanoindentation. The observed decrease in E with increased temperature or decreased pO2 correlated with the changes in oxygen vacancy concentration and lattice parameter expected due to chemical expansion. We compared these results with those we calculated for several compositions of bulk (Pr, Ce)O2-δ via density functional theory, and found that the experimentally observed reduction in mechanical stiffness of reduced (Pr, Ce)O2-δ thin films exceeded that predicted computationally for bulk counterparts. These results demonstrate that the in operando mechanical properties of non-stoichiometric oxides used in thin film SOFCs can differ significantly from those expected from characterization of bulk forms or at standard temperature and pressure. Thus, this chemomechanical coupling must be considered when designing mechanically robust SOFCs with thin film electrode components.
Performance and Degradation of Solid Oxide Electrolysis Cells in Stack
Authors: Fang Qingping , Blum Ludger , Menzler Norbert H. 
Published: February 2020

A Solid Oxide Electrolyser (SOE) short stack consisting of two anode-supported cells (ASCs) was assembled in Jülich’s F10-Design. The ASCs are based on Ni/8YSZ (8 mol% yttria-stabilized zirconia) with an LSCF positive electrode (La0.58Sr0.4Co0.2Fe0.8O3-δ) and 8YSZ electrolyte. A CGO (Ce0.8Gd0.2O1.9) barrier layer was deposited between 8YSZ and LSCF by physical vapour deposition (PVD).
The stack was characterized in furnace environment in both fuel cell and electrolyser mode with 50% humidified H2 from 700 °C to 800 °C. At 800 °C, the area specific resistances (ASRs) were calculated to be 130 mΩcm² and 150 mΩcm² under fuel cell and electrolyser mode, respectively. Long-term electrolysis operation (endothermically) at 800 °C under constant current mode is being carried out with a current density of 0.5 Acm-2 and a steam conversion rate of 50% with 50% humidified H2. After 1500 h operation (status 09.12.2014), the stack showed an average voltage degradation rate of 0.7%/1000h. Electrical impedance spectroscopy (EIS) and analysis of distribution of relaxation time (DRT) showed that the degradation was mainly due to the increase of Ohmic resistance, and the electrode polarizations did not change with the chosen testing conditions. The stack is planned to be further operated at 700 °C after a 2000 h electrolysis period at 800 °C. The performance and degradation behavior of the stack at 700 °C and 800 °C will be analysed with the support of EIS and DRT.
A Packaged and Efficient SOEC System Demonstrator
Authors: Chatroux André , Reytier Magali , Di Iorio Stéphane , Bernard Charlotte , Roux Guilhem , Petitjean Marie , Mougin Julie 
Published: February 2020

High Temperature Steam Electrolysis, based on solid oxide electrolysis cells (SOEC) is a promising way to produce hydrogen with high efficiencies. The use of steam instead of liquid water requires less energy for the water molecule splitting, and the high temperature operation (between 700 and 900°C) allows the replacement of a part of the electrical energy by heat, which allows in theory a significant increase of the electrical efficiency compared to alkaline and PEM water electrolysis. Most of works in the field of SOEC around the world are carried out at the cell or stack level. Only few results at the system level, that is to say including the stack and all BoP (balance of plant) components, are reported in literature, although it is a key point because the heat management of the system has to be optimized to effectively reach the high electrical efficiency expected.
For that purpose, the CEA-LITEN has designed and tested a packaged SOEC system demonstrator. It allows producing between 1 and 2.5 Nm3/h of H2 depending on the selected operating point, based on a single stack and the required auxiliaries, including a steam generator at 150°C and high temperature exchangers to preheat the inlet flows from heat recovered in the exhaust gases. A 25-cell-stack already validated in terms of performance [1] is the "heart" of the system. The stack as well as the other components of the system will be described in details, as well as the test results. The first test is presented in Figure 2. At 700°C, the system produces 1.2 Nm3/h of H2 with a total electrical consumption of 3.9 kWh/Nm3, achieving 92% of efficiency, this efficiency corresponding to the higher heating value (HHV) of the produced hydrogen vs the electrical consumption of the system.
Indeed, Fig. 2 shows that during the first 3 hours of operation corresponding to the standby mode and endothermic operation, an external heating (through furnace resistances) is required. But after 3 hours, the operation mode switches from endothermic to slightly exothermic mode, leading to an increase of the hydrogen production up to the targeted flow rate of 1.2 Nm3/h after 5 hours, which is associated to a decrease of the furnace power and an increase of the efficiency. It can be seen that after 5 hours, the furnace power is decreased to zero, without any decrease of the stack temperature. It demonstrates that a 150°C heat source temperature is sufficient for the steam generation, and that a slightly exothermic operating mode of the stack is sufficient to preheat the inlet gas up to 700°C and compensate the heat losses of the system.
[1] M. Reytier et al, 20th World Hydrogen Energy Conference, 15-20th June 2014, Gwangiu, Korea; submitted to International Journal of Hydrogen Energy.

Figure 1
Aluminum Activation in Ionic Liquids
Authors: Shvartsev Boris , Gelman Danny , Lasman Itay , Krossing Ingo , Scholz Franziska , Ein-Eli Yair 
Published: February 2020

Aluminum (Al) is the third most abundant element (after oxygen and silicon) and the most abundant metal in Earth's crust. Al is quite remarkable as it holds a low density and it has the ability to resist corrosion due to surface passivation. This passivation layer protects Al from corrosion in a relatively wide range of pH and potentials. Nevertheless, in aqueous media, the layer is vulnerable in both highly acidic and basic environments, leading to rapid corrosion reactions. As an anodic material, Al has a theoretical gravimetric capacity of 2.98 Ah/gr and its volumetric capacity is as high as 8.1 Ah/cm3. For the sake of comparison, Li metal holds capacities of 3.86 Ah/g and 2.06 Ah/cm3, respectively.
In non-aqueous media electrochemical dissolution of Al is partly hampered due to inefficient and thus insufficient passivation layer removal prior to any current application. Similar issues pertain when the non- aqueous solutions employed are Room Temperature Ionic Liquids (RTIL). In the present work an activation of Al was studied in EMIm(HF)2.3F RTIL. For this specific electrolyte it was already established that electrochemical dissolution of Al occurs, in considerable rates, sufficient for application in Al-Air batteries [1]. The alteration of the surface, as detected by FTIR, XPS and STEM, suggests on the formation of passivating Al-O-F compounds on the surface, instead of native oxide passivation. The source of this specific activation is established in this work, and the surface of Al prior to and following activation was identified. The applied methodology was also used for identification and study of Al activation in other family of RTILs. The preliminary results of this specific electrochemical system will be also presented.

[1] D. Gelman, B. Shvartsev, Y. Ein-Eli, J. Mater. Chem. A. 2.47 (2014) 20237-20242.
The Development of Organic Ionic Plastic Crystals As Solid State Electrolytes for Energy Storage
Authors: Pringle Jennifer M , Howlett Patrick C , Jin Liyu , Chen Fangfang , MacFarlane Douglas R , Forsyth Maria 
Published: February 2020

Organic ionic plastic crystals (OIPCs) are a class of solid-state electrolyte material quite unique in their mechanical and transport properties; they combine the advantages of fast ion conduction with good stability and non-volatility even above their melting point. Significant progress has been made recently in the development of OIPCs for electrochemical devices such as lithium batteries and dye-sensitised solar cells.[1] The negligible volatility of OIPCs renders them more suitable than molecular plastic crystals for long-term device use, while the high thermal and electrochemical stability of many OIPCs fulfils an essential requirement for solid state electrolytes for many device applications.
Understanding the ion transport behaviour of OIPCs, both in their pure and doped state (i.e. in the presence of a small amount of a lithium salt, to enable their use in lithium batteries), is crucial for their development as solid electrolytes.
Here we present our investigations into the ion transport mechanism in these materials using both experimental data (single crystal XRD, multinuclear solid-state NMR, DSC, ionic conductivity and SEM) and theoretical techniques (molecular dynamics and second moment-based solid static NMR line width simulations).[2][3]
We also discuss the physical properties and application of the OIPC triisobutyl(methyl)phosphonium bis(fluorosulfonyl)imide (P1444FSI) doped with 4 mol% LiFSI. The good conductivity of this material (0.26 mS cm-1 at 22 °C) enables cycling of lithium cells (Li|LiFePO4) at room temperature, achieving about 160 mA h g-1 discharge capacity at 20 oC, which is the highest for OIPC based cells to date.[4]
References
[1] J. M. Pringle, Phys. Chem. Chem. Phys., 2013, 15, 1339
[2] L. Jin, K. M. Nairn, C. M. Forsyth, A. J. Seeber, D. R. MacFarlane, P. C. Howlett, M. Forsyth and J. M. Pringle, J. Am. Chem. Soc., 2012, 134, 9688-9697.
[3] L. Jin, S. de Leeuw, M. V. Koudriachova, J. M. Pringle, P. C. Howlett, F. Chen, M. Forsyth, Phys. Chem. Chem. Phys., 2013, 15, 19570-19574.
[4] L. Jin, P. C. Howlett, J. M. Pringle, J. Janikowski, M. Armand, D. R. MacFarlane and M. Forsyth, Energy and Environ. Sci., 2014, 7, 3352-3361.
Montmorillonite Composite Polymer Electrolytes Displayed Exceedingly High Ion Conductivity Oriented By Electric Field
Authors: Wang Robin Chih-Hsing , Chu Peter Po-jen 
Published: February 2020

Solid polymer electrolytes are nonvolatile with strong film forming strength. It is considered as critical components for next generation lithium battery to meet the many demnds of growing mobile electronic power industry. Improving ionic conductivity of polymer electrolyte suitable for LIB, is the most urgent technical challenge. We report in this study a novel polymer electrolyte system by incorporating surface functionalized clay into the PVDF-HFP/Ionic liquid/Li salt system under applied an electric field. Mineral clays bear large surface areas, high aspect ratio, numerous dissociable cations in the interlayer and low-dimensional nano structure. The application of electric field has effectively oriented clay layers uniformly and dispersed it homogeneously to form an ordered and alignment nanostructure which is confirmed by SEM. This super ionic feature is extremely favorable for delivering high ion conductivity in the solvent free electrolytes where the long range ordered inorganic moiety served to corporate rapid ion transport. X-ray diffraction and DSC measurements indicated that the α-phase PVDF crystalline form was decreased by the electric field. The variety of crystalline degree of the polymer matrix was determined. The ionic conductivity of the composite electrolyte were measured to over 10-3 S cm-1. AC impedance spectroscopy revealed that the ionic conductivity of the electrolyte membrane containing 3 wt% MMT attains an order of 10−3 S cm−1 at room temperature. Coin cells assembled with the LFP cathode reversible discharge capacities of 140 mAh g−1 at 0.1C, accompanied with high coulombic efficiency over 40 cycles.

Figure 1
Design of Solid Electrolytes for High Temperature Batteries
Authors: Cho Jang Hyeon , Im Chae Nam , Park Byeong June , Kang Seung Ho , Cheong Hae Won 
Published: February 2020

Thermal batteries have been used for many military applications such as missiles and ordnance devices. As the thermal battery is composed of anode, cathode, MgO based-molten salt electrolyte and additional heat source, its specific energy density is lower than those of commercial batteries.
By means of substituting MgO based-electrolyte to increase energy density of thermal batteries, we have indentified various ionic solid electrolytes such as LLT(La0.5Li0.5TiO3), LSTZ(Li3/8Sr7/16Ta3/4Zr1/4O3) and LLZ(Li7La3Zr2O12).
As a ruslt, we found out that the LLZ with additivies, Ca and Nb, presents not only excellent ionic conductivity but also stable discharge characteristics at high temperature(≈ 300oC). Additionally, we have verified that the LLZ solid electrolyte is suitable for the full scale of thermal batteries with high energy density.
α-MnO2 Nanoparticles with High Surface Area for Electrochemical Supercapacitor Application
Authors: Muhammed Shafi P , Chandra Bose A 
Published: February 2020

The large scale energy production and developments in renewable energy sources requires efficient energy storage systems. The physical and chemical charge storage techniques along with high power and energy density brought electrochemical supercapacitors (ECs) as a versatile power source. The high rates of charging and discharging with long cycle life as well as the economical and eco-friendly nature support ECs to various energy applications. Since the last couple of decades, Supercapacitors with various metal oxides as electrode materials got a great interest among researchers. Here we synthesised α-MnO2 nanoparticles by simple chemical precipitation method and are subjected to heat treatment at 300 ˚C, 500 ˚C and 700 ˚C. The structural formation of as- prepared and annealed MnO2 are confirmed by XRD analysis. The functional group and optical absorption studies are done by Fourier transform infrared spectroscopy (FTIR) and UV visible spectroscopy. The surface area of the samples is measured using Brunauer-Emmett-Teller (BET) method. Finally electrochemical properties are evaluated using cyclic voltammetry (CV) and galvanostatic charge-discharge techniques. The cyclic voltammogram and charge-discharge curve recorded indicates MnO2 nanoparticles annealed at 300 ˚C for 5 h shows better electrochemical behaviour.
The Effect of Membrane Fixed Charge on Ion Transport in All-Vanadium Redox Flow Batteries
Authors: Lei Yuan , Zhang Baowen , Bai Bofeng , Zhao Tianshou 
Published: February 2020

In a typical all-vanadium redox flow battery (VRFB), species crossover through membranes not only deteriorates cell performance, but also reduces battery’s lifetime. To address this issue of species crossover, a better understanding of the ion transport behaviors through an ion exchange membrane is essential. The fixed charge, a very important and typical membrane property, has a deep correlation with ion transport behaviors: Firstly, the fixed charge affects ion distributions in the membrane as a result of the membrane selective adsorption. Hence, the ion transport rate is affected by all the three of transport modes including diffusion, migration and convection. Moreover, the ion selective adsorption is crucial to obtain the accurate ion diffusivity. Secondly, counter ions in the membrane may also transport via the swing of the charged functional groups. The characteristic of ion transport behavior in this way depends on the relative amount of the fixed charges and movable ions, and reflects in the ion diffusivity. However, both numerical and experimental investigations rarely concern about the intrinsic influence of the fixed charge on ion transport as the membrane parameters cannot be precisely controlled separately and an integrated impact of membrane is reflected in measured ion diffusivity. Therefore, it is urgent to explore how the fixed charge affects the ion transport behaviors.
In this work, we conceive, design and fabricate an experimental setup to study the characteristics of ion selective adsorption and ion diffusivities in an ion exchange membrane for VRFBs. As these two properties related to the relative amount of the fixed charges and movable ions, we take the amount of movable ions to be variables while the fixed charges constant to avoid the difficulty of precise production of membrane. We first perform an adsorption equilibrium test to explore the interactions between the fixed charge and movable ions. Two groups of vanadyl sulfate solution are prepared with a large difference in H+ concentration so that the amounts of total movable ions differ greatly. Each group contains three cases of vanadyl sulfate solution with the concentrations of the vanadium ion different. We then study the permeability to explore the transport mechanism. The membrane is placed between vanadyl sulfate solution and a blank one. The diffusivity can be acquired after a simple derivation. With an analysis of the same cases in the first step, the mechanism of the fixed charge affecting the ion diffusivity comes out.
All-Solid State Lithium-Sulfur Batteries
Authors: Cassel Alice , Viallet Virginie , Morcrette Mathieu 
Published: February 2020

Currently, lithium-ion batteries incorporated in electric vehicles do not allow to store enough energy to ensure sufficient autonomy. Therefore, it’s necessary to develop new generations of batteries with higher energy density. Among battery technologies, the lithium-sulfur system (Li-S) is considered to be one of the most promising solutions due to a theoretical energy density of 2500 Wh/kg. However, its lifetime remains limited due to the polysulfide shuttle effect, induced by the use of liquid electrolyte. Indeed, many polysulfides (noted Li2Sx 1 ≤ x ≤ 8), formed during the sulfur reduction to Li2S, dissolve in liquid electrolyte and diffuse between both electrodes, leading to a rapid decrease of electrochemical performances. All-solid-state Li-S batteries were studied in order to bypass the limitations of liquid electrolyte. The electrode is a composite material with sulfur (S8) as active material, argyrodite (Li6PS5Cl) as solid electrolyte for ionic conduction and Ketjen Black (KB) as additive conductor for electronic percolation. The liquid electrolyte between both electrodes is replaced by the solid electrolyte used in the composite electrode and metallic lithium is used as negative electrode. /sub>Sx 1 ≤ x ≤ 8), formed during the sulfur reduction to Li2S, dissolve in liquid electrolyte and diffuse between both electrodes, leading to a rapid decrease of electrochemical performances. The positive electrode was prepared by mixing and ball-milling at 370 rpm for 5h using a high-energy planetary ball mill, S8, Li6PS5Cl and KB with a weight ratio of 25:50:25. The battery displays a reversible capacity of 1565 mAh/g after 10 cycles at a current density of 134 µA/cm² (corresponding to a rate of C/10) with an initial discharge capacity of 1230 mAh/g and an extra capacity of around 335 mAh/g, observed for the first time and currently under studies. 8), formed during the sulfur reduction to Li2S, dissolve in liquid electrolyte and diffuse between both electrodes, leading to a rapid decrease of electrochemical performances. At high current density, with lithium negative electrode, we observed strange potential decreases that can be related to short circuit phenomena. One explanation for short circuit phenomena can be the formation of lithium dendrites, although they are not supposed to grow in solid electrolyte. The presence of dendrites will be evidenced by solid state NMR. Using alternative Li-In electrode, this phenomenon was totally suppressed. In this presentation, we will then show our best optimized solid state batteries using a Li-Indium electrode with a good capacity (1660 mAh/g after 10 cycles at C/10), a good coulombic efficiency and a reasonable polarization for a solid-state battery and at room temperature. Perspectives in term of energy density and industrialization (upscale of the lithium ion conductors) will be presented.
(Invited) Synthesis and Structures of Free-Base [14]Tribenzotriphyrin(2.1.1) and Their Metal Complexes
Authors: Xue Zhaoli , Wang Yemei , Ou Zhongping 
Published: February 2020

Subporphyrins are analogues of porphyrinoids that contain only three pyrrole or isoindole rings linked by meso-sp2 carbon atoms. The first synthesis of tribenzosubporphyrins was reported by Osuka’s group in 2006 with very harsh conditions. From then on, lots of subporphyrin analogues have been reported. However, almost all of these reported subporphyrins existed only as bowl-shaped boron complexes and the yields are typically very low. In 2008, we reported a facile synthesis of meso-aryl-substituted [14]benzotriphyrin(2.1.1) compounds based on a modified Lindsey condensation method in moderate yields up to 35%. These compounds represent the first example of near planar core-free contracted porphyrinoids with 14-π-electron aromatic systems containing only the standard pyrrole and isoindoline moieties. X-ray diffraction analysis revealed that the triphyrin core is near planar. Till now, different kinds of [14]Tribenzoriphyrin(2.1.1)-metal complexes have been synthesized and characterized including Ag(I), Mn(I), Fe(II), Re(I), Ru(II), Pd(II), Rh(III), Pt(II) and Pt(IV).
(Invited) Oxidation Chemistry of Manganese Porphyrins in Interaction with DNA
Authors: Pratviel Genevieve 
Published: February 2020

Metalloporphyrins associated with oxygen atom donors are biomimetic models of heme, enzymes such as cytochrome P450 and peroxidases. Some cationic porphyrins recognize DNA (double-stranded DNA and G-quadruplex DNA) with high specificity and selectivity. In aqueous buffer manganese porphyrins are activated by oxone. Two examples of oxidation reactions mediated by cationic manganese porphyrins in complex with DNA will be presented. Oxidation can be directed toward DNA and results in highly selective DNA damage (i) or may be directed toward oxidation of small molecules in a heme DNAzyme context (ii). DNA damage mediated by manganese porphyrins allowed a better understanding of the reactivity of high-valent metal-oxo species. The reaction pathway (electron abstraction versus oxygen atom transfer) depends on the protonation state of the water molecule present as axial ligand trans to the metal-oxo. The analysis of the reaction products of a manganese porphyrin in complex with G-quadruplex DNA gives insights on the mode of interaction of the porphyrin with DNA.
- Interaction of cationic manganese porphyrin with G-quadruplex nucleic acids probed by differential labeling of the two faces of the porphyrin V. Pradines, G. Pratviel Angew. Chem. Int. Ed. 52, 2185-2188 (2013)
- Protonation state of trans axial water molecule switches the reactivity of high-valent manganese-oxo porphyrin J. Trzcionka, J. Irvoas, G. Pratviel New J. Chem. 37, 3581-3590 (2013)
- Porphyrins in complex with DNA: modes of interaction and oxidation reactions G. Pratviel Coord. Chem. Rev. http://dx.doi.org/10.1016/j.ccr.2015.07.003