bluuebunny/crossref_metadata_2025_split huggingface dataset:
H2/O2 Alkaline Membrane Fuel Cell Performances Using Carbon-Supported Metal Phthalocyanine (MPc/C,M = Co, Cu, Zn, Ni) as Cathode Catalysts
Authors: Zhu Taishan , Qing Xin , Xu Pan , Song Yanxi , Qiao Jinli 
Published: February 2020

Supercapacitors are one of the most promising electrochemical energy-storage device and have been widely applied due to their advantages of large power density, long cycle stability and environmentally friendly[1]. In the past few decades, many metal oxides were investigated as active electrode material for supercapacitor, among which ruthenium oxide (RuO2) is the best candidate[
2-3]
. However, the high cost and toxic nature of RuO2 has limited its practical production and commercial applications.
Aiming at new cost-effective, high performance electrode material for supercapacitors, partial or complete replacement of precious metal has been under great effort by many research groups[4]. Manganes oxide (MnO2) is generally considered to be the most promising transition metal oxide for the next-generation supercapacitors by virtue of its high energy density, low cost, environmental friendliness, and natural abundance. For obtaining the specified morphology with increased surface area and predetermined microstructure, the MnO2 has been proposed to be synthesized by various methods such as hydrothermal method[5] and microwave method[6] to realize the improved reaction kinetics. However, these methods are relatively complex, which inevitably adds the cost. In this work, use glucose reducing potassium ermanganate, the mesoporous MnO2 can be easily prepared at ambient conditions with high production rate. Thus a very simple, economic and green synthesis procedure is realized compared to other procedures reported in the literature. In addition, the as-prepared mesoporous MnO2 exhibits high-performance in electrochemical capacitors.
(Invited) Advanced Materials for Electrochemical Systems
Authors: Li Dongguo , Kang Yijin , Strmcnik Dusan , Markovic Nenad M , Stamenkovic Vojislav 
Published: February 2020

Fundamental understanding of processes that are relevant for energy conversion and storage have been in the research focus that will be presented. Atomic scale insight at the electrified solid-liquid interfaces is considered critical in further advancement of materials that could be implemented in electrochemical systems such as electrolyzers, batteries and fuel cells.
It has been demonstrated that fine tuning of the surface properties can lead towards unprecedented improvements in their functional properties that are relevant for electrochemical technologies. This presentation will address unique research approach that is capable of revealing structure-function relationships in the design of tailored materials for electrochemical systems. The following topics will be discussed: well-defined materials obtained by varying their surface structure, composition profile and electronic properties; atomic/molecular insight into electrified solid-liquid interfaces; modeling of electrochemical systems; identification of the active and the most vulnerable surface sites under reaction conditions; insight into chemical nature between the surface atoms, reactants, and molecular species in the electrolyte; engineering of advanced nanomaterials with desired size, shape and composition profile; ex-situ and in-situ characterization of tailored nanostructured electrochemical interfaces.
This synergistic approach encompasses highly diverse experimental and theoretical methods and has been proven to serve as a foundation in the development of novel materials with advanced properties.
Understanding on Electrochemical Structure of Low Temperature Proton Exchange Membrane Fuel Cells
Authors: Andersen Shuang Ma 
Published: February 2020

Membrane electrode assembly (MEA) is the heart of a PEM fuel cell. In the catalyst layer, the electrochemical reactions only happen on the catalyst, which has simultaneous access to proton, electron and gas. Therefore, it is also called three-phase boundary (TPB). The larger and more stable TPB, the better performance of the cell will be.
Different from fundamental material studies, catalyst performance was evaluated based on the electrode structure point of view. Interaction between catalyst or catalyst support with Nafion ionomer was systematically investigated through an adsorption isotherm study[i], [ii]. Various adsorption strengths were observed depending on the surface properties of the absorbent. The structure of the resulting catalyst-ionomer-electrode (CIE) and the corresponding degradation pattern due to accelerated stress test were monitored with X-ray photoelectron spectroscopy[iii]. Based on our earlier studies[iv], the polymer phase can directly influence the other two phases in the electrode. Degradation of the polymer / corruption of the interphase structure in the catalyst layer can be the bottle neck of the overall challenge. Corresponding strategy for the improvement is proposed.

[i] Carbon, 71 (2014) 218-228.
[ii] J. Phy. Chem. C, 118 (2014) 10814–10823.
[iii] J. Power Sources, 274 (2015) 1217-1223.
[iv] ACS Appl. Mater. Interfaces 6 (2014) 16565−16576.
Surface Segregation and Inter-Diffusion of Cations and Impurities in Microelectrodes for Solid Oxide Fuel Cells and Electrolyzers
Authors: Téllez Helena , Druce John , Shi Yanuo , Kubicek Markus , Simrick Neil J. , Rupp Jennifer L. M. , Ishihara Tatsumi , Kilner John A. 
Published: February 2020

The surface segregation and inter-diffusion of cations and impurities in La0.6Sr0.4Co0.8Fe0.2O3-δ (LSCF) micro-patterned electrode structures on a single crystal Zr0.84Y0.16O1.92(YSZ) electrolyte was investigated by high-resolution ion beam analysis (Time-of Flight Secondary Ion Mass Spectrometry and Low-Energy Ion Scattering). The outermost and near surface of these microelectrodes showed significant changes in the distribution of the cations and impurities after micro-patterning, annealing and electrochemical testing of the cells. As occurring for bulk LSCF ceramics, strong segregation of Sr towards the electrode surface is observed during annealing of the microelectrode, as well as due to the thermal treatments required for electrochemical measurements. This segregation might have a drastic effect on the surface oxygen exchange reaction as the electrochemically active transition metals (Fe, Co) are not directly exposed to the gas phase. Impurities, such as Si and Ca, are also observed at the annealed electrolyte surface. Furthermore, the microstructured electrode showed that impurities can also migrate between the different components (i.e. Na and Si impurities migrate from the electrolyte to the LSCF electrode, showing a “cleaner” surface after the thermal treatments).
This study has provided a further understanding of the migration and segregation of cations and impurities taking place in real devices, building upon previous studies performed on ceramics materials.

Figure 1
(Invited) Theoretical Approach for Understanding Oxygen Reduction at the Cathode Surface of Solid Oxide Fuel Cell
Authors: Koyama Michihisa , Ishimoto Takayoshi 
Published: February 2020

Doped lanthanum cobaltite and its derivatives are used as cathode materials in solid oxide fuel cell (SOFC), thus the cathodic reaction mechanism has been extensively investigated. As results, it is generally accepted that the dissociative adsorption of oxygen at the cathode surface is one of rate-determining steps. Therefore, it is important to understand factors governing the surface kinetics. Preceding experimental and theoretical studies have pointed out the correlation between electronic structure of doped lanthanum cobaltites and oxygen dissociation properties on surface, formation energy of oxygen vacancy, and oxygen diffusivity [1-6]. In our preceding study [7], we focused on the change of spin states in LaCoO3 to have a basis for analyzing catalytic properties of the material at the operation temperature. Further analyses in collaboration with experimental observation have clarified the electronic properties of LaCoO3 at the operation temperature on the basis of density functional theory calculations taking into account the statistical thermodynamics [8].
As an extension of our preceding studies, we will discuss how the electronic structure affects the surface kinetics in this study. We adopted the La0.5Sr0.5O3-δ as cathode material and prepared the (001) surface model with the LaO termination. The model consists of five layers with the total 48 atoms. For the electronic structure calculations, we used Vienna Ab initio Simulation Package (VASP) based on the density functional theory. U parameter is adopted as correction for electronic correlation calculation. We investigated the oxygen adsorption energy, vacancy formation energy and oxygen dissociation energy by changing the spin states of Co in La0.5Sr0.5O3-δ. We observed dependency of the calculated energies and the spin states. Based on the calculated properties, we will discuss the kinetic process of oxygen reduction at La0.5Sr0.5O3-δ surface together with the perspectives of future analysis.
References
[1] Z. Chen, C. H. Kim, L. T. Thompson, and W. F. Schneider, Surf. Sci. 619, 71 (2014).
[2] A. M. Ritzmann, M. Pavone, A. B. Muñoz-Garcia, J. A. Keith, and E. A. Carter, J. Mater. Chem. A 2, 8060 (2014).
[3] W. T. Hong, M. Gadre, Y. Lee, M. D. Biegalski, H. M. Christen, D. Morgan, and Y. Shao-Horn, J. Phys. Chem. Lett. 4, 2493 (2013).
[4] S. Mukhopadhyay, M. W. Finnis, and N. M. Harrison, Phys. Rev. B 87, 125132 (2013).
[5] A. Kushima, S. Yip, and B. Yildiz, Phys. Rev. B 82, 115435 (2010).
[6] Y. Lee, J. Kleis, J. Rossmeisl, and D Morgan, Phys. Rev. B 80, 224101 (2009).
[7] T. Ishimoto, Y. Ito, H. Kohno, M. Koyama, ECS Trans., 57(1) (2013) 2655-2660.
[8] T. Ishimoto, Y. Ito, T. Tada, R. Oike, T. Nakamura, K. Amezawa, M. Koyama, submitted
Acknowledgement
The activities of INAMORI Frontier Research Center is supported by KYOCERA Corporation.
Anodes Derived from Fluorite-Type and Perovskite-Type Metal Oxides for SOFCs
Authors: Thangadurai Venkataraman , Singh Kalpana , Handal Hala Talaat , Mirfakhraei Behzad 
Published: February 2020

Solid oxide fuel cells (SOFCs) are alternative energy conversion devices, which deliver high quality power with a high efficiency using variety of fuels, including H2 and hydrocarbons. At present, composite Ni with Y-stabilised zirconia (YSZ) is widely used as an anode for SOFCs [1]. However, technical challenges due to coking and sulfur poisoning are yet to overcome when direct hydrocarbon-containing fuels are used. Ni not only possess good catalytic activity towards H2 oxidation and hydrocarbon reforming, it also catalyses carbon formation and poorly resists sulfur poisoning [2]. To overcome these problems, several alternatives such as Cu/CeO2/YSZ [3] and LSCM (La1-xSrxCr1-xMnxO3) [4] have been investigated. Though, these materials were able to resist coke and sulfur poisoning, they were not able to satisfy all the requirements of ideal SOFC anodes.
In the present study, mixed ionic electronic conducting (MIECs) Ce0.8Y0.1Mn0.1O2-
d and BaZr0.1Ce0.7Y0.1M0.1O3−δ (M = Ni and Co), and composite Ni and Ba0.5Sr0.5Ce0.6Zr0.2Gd0.1Y0.1O3-δ (BSCZGY) have been investigated as SOFC anodes. The cell performance of a button cell: Ce0.8Y0.1Mn0.1O2-
d/Zr0.84Y0.16O2-
d/La0.6Sr0.4MnO3+Zr0.84Y0.16O2-
d
was tested at 800 oC in 3 % H2O-H2 as a fuel and air as an oxidant. There was an obvious enhancement of the cell performance upon exposure to 10 ppm H2S-H2 for 48 h. Another area of the MIEC anodes development involves investigation of perovskite-type BaZr0.1Ce0.7Y0.1M0.1O3−δ (M = Ni and Co). The BaZr0.1Ce0.7Y0.1Ni0.1O3−δ compound shows a promising low polarization resistance of 0.4 Ω.cm2 at 800oC in H2. Low polarization resistance of the BaZr0.1Ce0.7Y0.1Ni0.1O3−δ perovskite, as a non-composite anode without any additional electron conductive phase, makes it a promising material for SOFC anodes.
Proton conducting doped BaCeO3 materials is the frontrunners as electrolyte in the field of low temperature (400-700 oC) proton-SOFCs. A and B site co-doped Ba0.5Sr0.5Ce0.6Zr0.2Gd0.1Y0.1O3-δ has shown good chemical stability in CO2 and humid atmospheres at elevated temperature [5]. In the present work, anode performance of Ni-BSCZGY composites (with Ni: BSCZGY ratios as 30:70, 40:60 and 50:50) has been studied. Screen-printing and co-firing processes were employed to make symmetrical cell: Ni-BSCZGY/BSCZGY/Ni-BSCZGY. Area specific resistance (ASR), capacitance and activation energy values were studied to evaluate the electrochemical performance of the anode composites. 50:50 composite shows the lowest ASR value among the current investigated anode compositions (30:70 and 50:50).

References

1) M. Ihara, T. Kusano and C. Yokoyama, J. Electrochem. Soc.,
148, A209 (2001).
2) Zhe Cheng and Meilin Liu, Solid State Ionics,
178, 925 (2007).
3) H. Kim, S. Park, J.M. Vohs and R.J. Gorte, J. Electrochem. Soc.,
148, A693 (2001).
4) S. Tao and J.T.S. Irvine, Nature Letters,
2, 320 (2003).
5) R. Kannan, S. Gill, K. Singh, T. Fürstenhaupt and V. Thangadurai, Sci. Report,
3, 2138 (2013).
Electrochemical Explorations of 9,10-Anthraquinone/Hafnium(IV) Ion Interactions in Nonaqueous Solvents
Authors: Cheek Graham T. 
Published: February 2020

Introduction
The well-defined electrochemical behavior of quinones such as 9,10-anthraquinone (AQ) in nonaqueous solvents (1,2) suggests its use as a probe for interactions of metal cations with the AQ carbonyl oxygens. In previous work from this laboratory, the interaction of AQ with added Al(III) trifluoromethanesulfonate [Al(TfO)3] in adiponitrile has been shown to produce a shift in the initial AQ reduction process to more positive potentials (3). In contrast to the behavior seen for 9-fluorenone (4), however, the second AQ reduction process disappears even at the 0.4 : 1.0 Al3+ : AQ point. This observation suggests that AQ reduction products are good ligands for the Al3+ cation, with approximately three reduced AQ ligands coordinated to one Al3+. The present work explores whether this effect extends to other metals, particularly Hf4+. The general effect of Hf4+ on the cyclic voltammetry of AQ in adiponitrile is also treated.
Experimental
Adiponitrile (AN) and 9,10-anthraquinone (AQ) were obtained from Aldrich Chemical Co. Hafnium trifluoromethansulfonate [hafnium triflate, Hf(TfO)4] was obtained from Alfa-Aesar. Tetraethylammonium tetrafluoroborate [TEA BF4] was purchased from Southwestern Analytical Chemicals (SACHEM). Voltammograms were acquired with a PAR283 potentiostat using PowerSuiteTM software. Potentials are reported with respect to a Ag/AgCl (0.1M EMICl in EMI BF4) reference electrode (Cypress Systems). Vitreous carbon electrodes were obtained from Cypress Systems. All experiments were carried out in a Vacuum Atmospheres drybox.
Results and Discussion
A cyclic voltammogram of AQ in adiponitrile without added Hf(TfO)4 is shown in Figure 1a, which shows the usual two uncomplicated successive one-electron transfers. Upon addition of Hf(TfO)4 at the 0.4 : 1.0 Hf4+ : AQ level, however, a substantial positive potential shift is observed for AQ reduction (Figure 1b). This shift is due to complexation of one of the AQ carbonyl oxygens by Hf4+. As in the case of Al3+ addition, there is none of the original second AQ redox process at this point. This observation implies that Hf4+ is complexed by multiple AQ reduction products, as was also seen for Al3+ addition. Further additions of Hf(TfO)4 give only the shifted reduction process at the 1:1 Hf4+ : AQ point, with substantially more of the small reduction peak at +0.1 V in Figure 1b. The latter observation suggests the possibility that both AQ carbonyl oxygens can undergo complexation by Hf4+ in this system. The present results indicate extensive interaction of Hf4+ with AQ, including the role of reduced AQ species as multiple ligands for Hf4+.
References

N. A. Macıas-Ruvalcaba and D. H. Evans, J. Phys. Chem. C,
114
, 1285 (2010).

L. Jeftic and G. Manning, J. Electroanal. Interfacial Echem, 26, 195 (1970).

Electrochemical Society 226th Meeting, Fall 2014, Cancum, Mexico, ECS Abstract H1-1345.

D. Canby, E. Sanders,and G. T. Cheek, J. Electrochem. Soc., 160(7), G3159 (2013).

Figure 1
Second Generation Aqueous Electrolyte Electrochemical Cells for Scaled Stationary Energy Storage
Authors: Whitacre Jay 
Published: February 2020

The design and function of next generation aqueous electrolyte dual-intercalation energy storage devices and systems will be discussed. These system use relatively unexplored electrode interactions that exploit muti-cation reactions (eg lithium, sodium and proton interactions all can contribute to the energy storage function). The core device uses a configuration wherein the active anode material consists of a blend of carbon-coated NaTi2(PO4)3 and activated carbon and the cathode is cubic spinel l-MnO2 that has resident lithium. The electrolyte is a blend of Li+ and Na+ and hydrogen (at some states of charge) cation species, with SO4
- and OH- (at some states of charge) as the countering anions, solvated in an initially neutral pH aqueous electrolyte.
Improvements to the original large-format devices first disclosed in 2011 will be disclosed, and data will be presented showing that large scale industrially packaged batteries with over 3000 Wh in capacity have be produced and qualified. Data showing the relationship between electrode thickness, current collector resistance, and overall battery performance will be shown. Systems containing packs of these batteries in the multi-kWh range have been effectively implemented in field-testing around the world. These applications include support for both smaller off-grid applications with bus voltages in the in the 20 to 100 V range, as well as, grid compatible systems with bus voltages in excess of 1000 V.
The Electrochemical Properties of Diamond and Tetrahedral Amorphous Carbon Electrodes in Room Temperature Ionic Liquids
Authors: Swain Greg M , Jarosova Romana , Munson Catherine 
Published: February 2020

Room temperature ionic liquids (RTILs) are emerging as a new medium for redox reactions as these liquids possess high solubilizing power, electrical conductivity, wide breakdown voltage and low volatility. Being composed entirely of ions (no solvent) and possessing wide electrochemical windows (
ca.
5 V), it is not difficult to see why these liquids are viewed by electrochemists to be attractive electrolytes for investigation. Our group is (i) studying the wetting of these ionic fluids on different carbon electrode surfaces and how this wetting affects the capacitance-potential relationships and (ii) investigating how the carbon electrode surface chemistry and microstructure affect the heterogeneous electron-transfer rate constant of different inorganic and organic redox systems in these ionic liquids. It is well established that the in aqueous electrolyte solutions, the heterogeneous electron-transfer rate constant for certain redox-systems at ordered HOPG and more microstructurally-disordered glassy carbon is strongly affected by the electrode surface microstructure and chemistry. We seek to learn if these same trends hold in ionic liquids.
In this presentation, we will compare the electrochemical behavior of boron-doped nanocrystalline diamond and nitrogen-incorporated tetrahedral amorphous carbon thin-film electrodes. Specifically, contact angle measurements of the surface wettability, measurements of the double-layer capacitance (C
dl) and its variation with potential, and heterogeneous electron-transfer rate constants for redox systems in structurally distinct RTILs will be presented. These two carbon electrodes have distinct microstructures as compared to their sp2 carbon counterparts. Nitrogen-incorporated tetrahedral amorphous carbon (ta-C:N) is a composite material consisting of a mixture of sp2 and sp3-bonded carbon. Impurities can be incorporated during growth (e.g., N) further adding to their complex structure. These films typically possess 40-60% sp3-bonded carbon. It has been widely used as a protective coating due to its hardness, high wear resistance and low coefficient of friction. The growth temperature for ta-C is usually from 25 to about 100 °C. This means that non-traditional materials, such as plastics, can be used as substrates for deposition. Importantly, these carbon materials possess some electrochemical properties that are similar to those of diamond.
Electrochromic Properties of Non-Stoichiometric Ni1-Xo Thin Films
Authors: Da Rocha Mathias , Manceriu Laura , Rougier Aline 
Published: February 2020

NiO is a well known anodic electrochromic (EC) material showing optical modulation under electrochemical oxidation and reduction [1]. Despite the simplicity of this oxide, electrochromism in NiO thin films is rather complicated although it is generally accepted that the optical modulation is related to a charge-transfer process between Ni(II) and Ni(III). The NiO is commonly associated to WO3 in inorganic EC devices, a combination leading to a neutral color due to the simultaneous brownish and blue color of NiO in oxidized state and WO3 reduced state, respectively. Nevertheless, their association is complicated owing to their different stabilities in acidic/basic media, a factor which also impinges on the device stability. In our group, an unusual reactivity for non-stoichiometric Ni1-xO thin films cycled in various electrolytes was recently reported opening the choice of materials for complete devices working in both lithium and lithium free electrolyte [2].
Ni1-xO thin films were grown at room temperature by sputtering deposition on ITO-glass substrate. The influence of various partial pressures of O2 (a 4 Pa total pressure was maintained during deposition) on the stoichiometry, morphology and cristallinity of Ni1-xO thin films was studied and correlated to their EC behavior. Unsurprisingly, an increase in oxygen partial pressure is related to a stronger brownish appearance associated with to an increase in the Ni3+ amount as well as a decrease in film porosity and roughness. Moreover, the comparison of the electrochemical properties of Ni1-xO films cycled in aqueous (KOH), lithium based and lithium free ionic liquid electrolytes, shows an evolution from a faradic to a pseudo-capacitive behavior, while optical contrast from colorless to brownish remains in all cases. This suggests that electrochromism is not only the result of of small cations (de)insertion but also depends on surface phenomena including possible participation of anions.
Herein, the relationship between the physical-chemical properties and EC performances of non-stoichiometry Ni1-xO thin films will be investigated. Finally, the combination of Ni1-xO with WO3 and PEDOT in full devices will be discussed.
[1] C.G. Granqvist, Handbook of inorganic electrochromic materials, Elsevier, Amsterdam, Netherlands, 1995
[2] Moulki, H., Faure, C., Mihelčič, M., Vuk, A.S., Švegl, F., Orel, B., Campet, G., Rougier, A. Electrochromic performances of non-stoichiometric NiO thin films, Thin Solid Films, 2014, 553, 63-66.