bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Enabling Conversion-Based Metal Oxide Anodes for Li Ion Batteries through Material Confinement
Authors: Ng Benjamin , Mustain William E. 
Published: February 2020

The market demand for electric vehicles (EVs) and hybrid electric vehicles (HEVs) have pushed Li-based technologies towards new higher capacity materials. The end goal is to enable full EVs that recharge very quickly (5-10 min) and achieve similar driving range to fossil-fuel cars (400-500 miles). State of the art Li ion batteries can deliver a gravimetric energy density of approximately 250 Wh kg-1, which is equivalent to ~250 miles for an EV. For EVs to truly compete in the market, batteries with an energy density greater than 500 Wh kg-1 must be realized. One family of materials that has been proposed to replace graphite at the anode is conversion metal oxides, which have both higher capacity (700-1200 mAh/g vs. 372 mAh/g) and slightly higher operating potential. This means that metal oxides have the potential to concomitantly increase energy density and improve safety (by avoiding Li plating during fast charge). Unfortunately, many of the metal oxide anodes that have been reported in the literature have shown poor cycle life and low coulombic efficiency.
In this presentation, we will discuss each of the degradation mechanisms that act to reduce capacity, capacity retention and coulombic efficiency of conversion metal oxides in Li-ion batteries. We will present new data on the influence of the electronic conductivity of these materials as well as the growth dynamics of the solid electrolyte interphase (SEI). It will be shown that there are two primary degradation pathways for metal oxide anodes in lithiuim ion batteries and a new strategy based on material confinement will be presented to simultaneously mitigate both. A combination of physical (TEM, S/TEM, XPS) and electrochemical (charge/discharge, EIS) characterization will be used to explain the behavior of these materials, and materials combinations that allow for achieved capacity of 800 mAh/g, capacity retention over 1000’s of cycles and coulombic efficiency > 99.5% will be presented.
Oxygen Transport Resistance in PEMFC Catalyst Layer Based on Ultra-Micro Electrode (UME) Theory
Authors: Lu Zijie , Yang Jun , Xu Chunchuan , Wang Chunmei , Waldecker James 
Published: February 2020

Hydrogen fuel cell is a promising zero-emission automotive powertrain for larger vehicles with long-distance requirements. However, its cost must be reduced to achieve real commercial use. Minimizing use of precious metal catalysts and increasing the fuel cell power density have been the most viable means to reduce the stack cost. Focus of advanced research is shifting to improve the fuel cell power density (> 1 W/cm2) with low Pt-loaded catalyst layers (≤ 0.125 mgPt/cm2 total).
One of the emerging issues with the low loaded fuel cell electrode is the dramatic increase of oxygen transport resistance with Pt loading reduction. This has been observed for both diluted (with addition of carbon particles to maintain the layer thickness) and undiluted (thinner) electrodes. The mechanism for the transport resistance increase in low Pt loaded electrode is not well understood and the quantitative modeling of the resistance is scarce. In this work, we propose a simple explanation to the oxygen transport in the catalyst layer based on the assumption that each active Pt particle functions as a semi-spherical nano-electrode, which is covered by a layer of proton conducting matter (ionomer, water film, or a combination of two). Without any other assumption, the oxygen transport resistance in the catalyst layer can be analytically determined, for the case of limiting current density, as
RMT,CL = coth(Φ⋅sqrt(4πRρK)) / sqrt(4πRρ⋅Dion⋅DCL)
This model identifies several critical factors that influence the oxygen transport resistance, including the CL thickness, the Pt particle density, and the diffusivities of oxygen in proton conducting phase and in CL voids.
In order to verify this model, a Pt/C catalyst with different Pt:C ratios (ca, 5:5, 3:7 and 1:9 by weight) were fabricated into MEAs and their mass transport resistances were measured with the limiting current method. The I/C ratios and the Pt loadings of the catalyst layer were also varied to investigate the complex interactions of the CL thickness, Pt particle density and CL microstructure (e.g., porosity). The results are compared to the estimates from the above model.
Application of Platinum Nanoparticles Decorated Needle-Shaped Cobalt for Methanol and Ethanol Oxidation
Authors: Norkus Eugenijus , Zabielaitė Aušrinė , Šimkūnaitė Dijana , Vaičiūnienė Jūratė , Pakštas Vidas , Tamašauskaitė-Tamašiūnaitė Loreta 
Published: February 2020

Low-temperature fuel cells operating on methanol or ethanol fuel comprise a promising class alternative sources of energy. Active search for cost-effective and efficient catalysts is still in progress. In this study, the oxidation of methanol and ethanol has been investigated on the needle-shaped cobalt (Coneedle) catalyst decorated with low amounts of platinum nanoparticles (PtNPs). The electrochemical and chemical methods were used for the fabrication of the PtNPs decorated needle-shaped Co catalysts. The electrocatalytic activity of the as-prepared PtNPs-Coneedle catalysts for the oxidation of methanol and ethanol in an alkaline media was evaluated using cyclic voltammetry and chrono-techniques. The data on methanol and ethanol oxidation under different conditions will be presented and discussed.
It has been determined that the decoration of the needle-shaped cobalt catalyst with low amounts of Pt nanoparticles results in enhanced electrocatalytic activity for methanol and ethanol oxidation, compared with that of pure needle-shaped Co and seem to be a promising anode material for direct methanol and ethanol fuel cells.
A Gold-Polyaniline Nanocomposites Catalyst with a Posy Bouquet Structure for Efficient Electrocatalytic Reduction of CO2.
Authors: Vijayakumar Amruthalakshmi , Zhao Yong , Wang Caiyun , Wallace Gordon 
Published: February 2020

The concentration of atmospheric CO2 rose up significantly due to the extensive use of fossil fuel as the main energy source since the industrial revolution in 19th century. In 2015, it has already exceeded the upper safety limit of 350 ppm and reached as high as 401.3 ppm [1]. This has been considered as the main cause of global warming, ocean acidification, desertification etc. The electrochemical reduction of CO2 (CO2ER) at room temperature that can produce value-added chemical feedstock and liquid fuels by using the electricity from renewable energy sources is an attractive way for CO2 recycling [2, 3].
Generally, CO2ER suffers from sluggish kinetics and poor selectivity since the CO2 molecule is highly stable that requires high energy to be activated, the electrochemical potential differences between different products are small, and the competitive H2 evolution reaction (HER).Developing selective and efficient catalysts is the key challenge for CO2ER.Gold (Au) is one of the best catalyst investigated for the CO2-to-CO conversion [4, 5]. However, cost and availability limiting its wide applications. Integrating gold with suitable conductive support to form composites can reduce the cost by minimal the usage. Also, these catalysts can deliver remarkably an improved catalytic performance in terms of Columbic efficiency and selectivity due to the synergistic interaction between the metallic catalytic center and conductive support through the enhanced charge transfer by providing σ electron and stabilization of metallic center via weakened binding ability of *CO reaction intermediate [6, 7].
Herein, we synthesized an efficient catalyst, gold-polyaniline (Au-PANI) nanocomposites with a posy bouquet structure by an ecofriendly one-step redox reaction at ambient conditions. This composite displayed a high faradaic efficiency of 85% for CO formation with a high partial current density of 11.6 mA cm-2 at -0.9 V vs. reversible hydrogen electrode (RHE) in 0.1 M KHCO3 aqueous solution, much higher than that for gold nanoparticles or the annealed gold-polyaniline nanocomposites (Au-NC).This work clearly demonstrates the influence of PANI on the CO2ER performance for Au-PANI composite.
References

Pieter and R. Keeling. "NOAA/ESRL (www. esrl. noaa. gov/gmd/ccgg/trends/) and Scripps Institution of Oceanography (scrippsco2. ucsd. edu/)." Acessadoem (12/10/2011) (2015).

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Zhao, C. Wang, Y. Liu, D. R. MacFarlane and G. G. Wallace, Adv.Energy Mater., 2018,1801400.

Zheng, K. Jiang, and H. Wang,Adv. Mater.2018, 1802066.
CO2 Reduction to CO on Au: Facet Dependent Activity and Selectivity
Authors: Seger Brian , Mezavilla Stefano , Chorkendorff Ib 
Published: February 2020

Due to the drastic drop in renewable electricity prices, electrochemical CO2 reduction has received renewed interest. While CO2 reduction can lead to a wide variety of products, almost all go through a CO intermediate, thus understanding the 2 electron transfer reaction of CO2 to CO is important not just for CO production, but also for products such as ethylene, ethanol, methane and others. Au has been shown to be the most active electrocatalyst for CO production, however major fundamental knowledge on this reaction has yet to be discovered. While most works focus on highly active nanostructured Au electrodes, there has yet to be a comprehensive study on the intrinsic electrochemical activity of individual Au facets.
This talk will discuss our work on the electrochemical conversion of CO2 to CO on single crystal Au <100>, <111>, <110>, and <211> facets as well as polycrystalline Au. Our results show a 25 fold difference between the least and most active crystal facets. All facets follow approximately the same Tafel slope between the tested potentials of -0.6 V to -0.8 V vs. RHE. Pb underpotential deposition (UPD) was used to deposit a monolayer of Pb on the Au gold surface to determine surface area. However, the potential at which Pb UPD deposits is facet dependent. By setting a correct potential we could selectively deposit lead on a given facet. While PB UPD favored depositing on the most active sites, we still could gain fundamental catalysis knowledge. On polycrystalline Au, 20% of a monolayer of Pb yielded a 50% decrease in CO production, but only a 30% decrease in H2 production. 50% of a Pb monolayer on Au yielded a 95% decrease in CO production, but only a 50% decrease on H2 production. The decrease in CO production as a function of Pb coverage indicated that not only could we passivate the most active sites, but also that the facet dependent activity was quite different for CO production versus the competing H2 evolution side reaction.
To further utilize Pb UPD to isolate sites we reinvestigated one of our least active facets, Au <111>. As expected, STM images show that our single crystal is not completely flat and there is a small percentage of step sites. We used selective Pb UPD to deposit 4% of a monolayer in the attempts to passivate these sites. This led to a 50% decrease in CO activity, but the same H2 evolution activity. Covering the Au with 15% of a monolayer led to a 90% drop in CO activity, but the same H2 evolution activity. These results suggest that our intrinsic activity of our least active facets is probably much lower than measured and is dominated by a small number of highly active defect sites. While these results focus on Au, no single crystal is defect free. Thus these results may lead us to also question whether there are other situations where the non-optimal facets for a given reaction are actually much less active than originally thought.
Sustainable Hydrogen Production Using Water By a Photovoltaic Integrated Electrolyser with Active Area Exceeding 100 cm2
Authors: Calnan Sonya , Kemppainen Erno , Aschbrenner Stefan , Bao Fuxi , Schlatmann Rutger 
Published: February 2020

Hydrogen generated by electrochemical water splitting driven by solar energy presents a near zero carbon emission means of energy storage. For the wide scale deployment of this technology, it is necessary to reduce costs of the components by reducing the amount of scarce materials used on one hand on the other hand, simplifying the device design. In this work, a fully integrated photovoltaic driven electrolysis system is designed in which the electrical connection of the device is wholly internal and the two energy conversion components are inseparable. Also transfer of heat from the back of the PV minimodule to the electrolyte is facilitated by thermal contact. Computational fluid dynamics simulations were used to optimise the geometry as well as the feedstock and thermal management in the device. The PV minimodule with a total area of 294 cm², consisted of silicon heterojunction solar cells while the electrolysis cell used 1.0M KOH electrolyte and 100 cm² nickel foam electrodes for water splitting. The hydrogen production efficiency of the entire device was tested under different irradiation and ambient temperature conditions without additional heating. Outdoor tests under irradiation levels of about 500 W/m² recorded hydrogen production rates of reaching 85 µg cm² s-1, corresponding to solar-to-hydrogen conversion efficiencies around 5 %. The use of better catalysts and higher irradiance conditions are expected to contribute to improved device performance.
Figure 1: Photograph of the photovoltaic integrated electrolyser during outdoor tests

Figure 1
(Invited) Preparing Composite Electrolytes: A Comedy in Two Acts
Authors: Zawodzinski Thomas A. 
Published: February 2020

Composites of polymers and inorganic particles are a favorite approach in the literature on preparing electrolytes with desired properties. This is a result of several different aspects. First, such composites are judged to be relatively easy to prepare. Inorganic nanoparticles as well as those such as graphene or carbon nanotubes are readily available. Compounding the materials is often carried out by co-casting from solutions/suspensions.
In this work, we provide a case study of composite formation in two parts. The overall goal was to prepare a proton conducting composite in which the conducting component was provided by sulfonic acid terminated grafts on oxide particles. In the first part, we detail our first attempt at this, in which we used silica particles onto which we synthesized silane grafted alkyl bromides which were then converted into two steps to sulfonic acids. These were prepared in composites with PVDF. This first attempt yielded poor conductors. Investigations suggested poorly connected composite domains. In short, reflection revealed that we did almost everything wrong.
In the second part of the work, we dissected the reasons for failure and sought to create optimal conditions for composite formation with high numbers of charge carriers and good interconnections within the networks of components. This was achieved by using different sulfonate formation chemistry, different particles and, importantly, polymeric components with different levels of functionalization to allow us to tune the interactions between particles and binder. The result of this was a much more effective conductor.

Acknowledgement

We gratefully acknowledge the support of this work by the Department of Energy. The significant contributions of Dr. Berry Decker and Dr. Hossein Ghassemi of Case Western Reserve University are also appreciated.
Tailoring Microstructures and Ionic Conductivities of Li1+XAlxGe2–X(PO4)3 (LAGP) Solid Electrolytes for All-Solid-State Batteries
Authors: Kim Yong-Chan , Park Min-Sik , Jung Kyu-Nam 
Published: February 2020

Lithium ion batteries (LIBs) have been successfully utilized as power sources for various electronic devices (e.g. mobile phone, remote controller, lab-top, etc.). Recently, the application of LIBs is extending to emerging markets such as electric vehicles (EVs) and energy storage systems (ESSs) for grid-supporting. Unfortunately, conventional LIBs still suffer from safety issues associated with the use of flammable organic electrolytes. To overcome such limitation of LIBs, many attentions have been devoted to the development of all-solid-state batteries (ASBs) that are employing solid electrolytes with excellent structural and electrochemical stabilities. Li1+xAlxGe2–x(PO4)3 (LAGP) is a kind of potential solid electrolytes with a NASICON structure. It offers relatively high bulk ionic conductivity (~10-4 Scm-1) with a wide electrochemical window and great moisture tolerance.[2] Owing to these advantages, LAGP can be a great option as a practical solid electrolyte for realizing ASBs. However, there are some technical issues to be resolved before commercial use of LAGP solid electrolytes as follow; i) a low ionic conductivity arising from the high boundary resistance and ii) a high synthesis temperature (i.e. energy consumable process).
In this work, the microstructures of LAGP solid electrolyte are tailored by addition of Bi2O3 and B2O3 with a purpose of improving the ionic conductivity and reducing the fabrication temperature. Based on various structural and electrochemical analyses, we investigate the correlation between microstructure and ionic conductivity of LAGP. In practice, Bi2O3 is able to improve the structural integrity of LAGP with turning down of the sintering temperature, leading to the densification of LAGP [1] and, on the other hand, B2O3 facilitates the grain growth of LAGP during synthesis.[3] As a result of co-addition of Bi2O3 and B2O3, the ionic conductivity of LAGP solid electrolyte increases about one order of magnitude higher than pristine LAGP. This work will provide a practical guideline to develop a highly reliable solid electrolytes for ABSs.
(Figure 1 image)

SD Lee and KN Jung, ChemSusChem
10, 2175 (2017)

Masashi Kotobuki, Keigo Hoshina, Yasuhiro Isshiki, Phosphorus Research Bulletin
24, 061 (2010)

Harsharaj S. Jadhav, Ramchandra S. Kalubarme, Seong-Yong Jang, KN Jung, Mo, Dalton Trans.
43, 11723 (2014)

Figure 1
Advanced Porous Membranes with Slit-like Selective Layer for Flow Battery
Authors: Qiao Lin , Zhang Huamin , Lu Wenjing , Xiao Chuanhai , Fu Qiang , Li Xianfeng , Vankelecom Ivo F.J. 
Published: February 2020

An advanced porous membrane containing slit-like selective layer on its top surface is designed and prepared for flow battery application. The structure is realized by regulating the parameters during membrane formation process. The porous membrane exhibits a thick skin layer with narrow slits and sponge-like support layer in the cross-section. The thick and comparatively hydrophobic skin layer hinders the passage of vanadium ions. Meanwhile, the slit structure and comparatively hydrophilic support layer facilitates the transport of protons. The resulting poly(ether sulfone) (PES)/sulfonated poly(ether ether ketone) (SPEEK) porous membrane containing slit-like selective layer achieves an excellent balance between ion selectivity and proton conductivity, resulting in a columbic efficiency of 98.5%, a voltage efficiency of 91.7%, and an energy efficiency of 90.4% at 80 mA cm-2, which is much higher than a vanadium flow battery (VFB) with the commercial Nafion 115. Therefore, this work provides a simple and economical method to develop high-performance, low-cost membranes for VFB applications.
Fig. 1 The principle of the nonsolvent-induced segregation of hydrophilic polymer chains in PES/SPEEK blend membranes.

Figure 1
Characterization of CaZrO3 Coating Layer Formed on YSZ Plate for SOM Anode in CaCl2-CaF2-CaO Electrolyte
Authors: Kim Wan-Bae , Nersisyan Hayk , Kwon Suk-Cheol , Yoo Bung-Uk , Lee Jong-Hyeon 
Published: February 2020

Conventional metal production ways using graphite anode emits pollutants such as CO2 and CO. This can be solved by replacing the graphite anode with the SOM anode, and YSZ is the representative SOM anode material. In this study, it was evaluated the formation behavior and characterization of CaZrO3 layer formed on YSZ anode surface due to in-situ reaction in CaCl2-CaF2-CaO electrolyte during electrolysis.
The experiment was performed in three stages: compacting, sintering and CaZrO3 layer formation reaction. First, the PVA was used as a binder to manufacture YSZ granule powder, green compact was made using uniaxial press. Second, the green compact was sintered in a box furnace. Finally, The CaZrO3 layer formation reaction was performed in a glove box. YSZ plates were analyzed by SEM/EDS and XRD for CaZrO3 layer formation, morphology, component and phase analysis. The yttrium concentration eluted into the electrolyte by CaZrO3 layer formation reaction was analyzed by ICP-OES. In order to evaluate the performance of YSZ including CaZrO3 coating layer as a SOM anode, ion conductivity was measured. In this paper, the stability of SOM anode with CaZrO3 layer will be discussed.
Characterizing the Performance of Biologically Templated Membrane Electrode Assemblies for Low-Loaded Electrodes in Proton Exchange Membrane (PEM) Electrolyzers
Authors: Kim ChulOong , Pramounmat Nuttanit , Renner Julie N. 
Published: February 2020

Hydrogen is one of the world’s most important chemicals. Hydrogen is produced at around 50 billion kg/year, and that number is expected to grow with increasing renewable usage in the future. Hydrogen generation via proton exchange (PEM)-based electrolysis is a promising technology because of its flexibility and deplorability.1 However, since platinum group metal catalysts are a major cost driving factor at large scales, a fundamental understanding the catalyst support interactions and the effect of architecture on PEM electrolysis performance is needed to reduce noble metal catalyst loadings.
This work focuses on investigating biologically templated electrode components. Specifically, we explore bi-functional material-binding proteins to position ionomer on or near catalyst sites and comparing the performance in a lab-scale PEM electrolysis cell. The work compares the performance of a baseline platinum coated cathode electrode to platinum cathodes with biological organization. Protein additives increase the performance of an ultra-low catalyst PEM electrolysis cell. This has implications across many other green, electrochemical technologies useful for the energy sector.
References

Ayers, K. E., Renner, J. N., Danilovic, N., Wang, J. X., Zhang, Y., Maric, R., & Yu, H. (2016). “Pathways to ultra-low platinum group metal catalyst loading in proton exchange membrane electrolyzers”. Catalysis Today, 262, 121-132. doi:http://dx.doi.org/10.1016/j.cattod.2015.10.019