bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural Behavior of Mixed Metal Oxide Nanoparticles As Electrocatalysts for the Oxygen-Evolution Reaction
Authors: Gliech Manuel , Klingenhof Malte , Bergmann Arno , Strasser Peter 
Published: February 2020

The storage of electric energy has become one of the main challenges in infrastructure development. The development of scalable, cost-efficient and robust synthetic routes toward well-defined solid state structures is a major objective in this field.
Electrocatalytic water splitting is a promising way of chemical energy storage wherein the anodic oxygen evolution reaction (OER) is the determining factor. Manganese based oxides have attracted particular attention as non-noble metal catalysts for the OER. Due to their abundance, low price and ecological harmlessness, those materials are promising candidates for a commercial application. Therefore insights into the relations between synthesis conditions, composition, structure and activity as well as stability are of fundamental interest. 1,2

Here, we present the comparison of different synthesis routes for Mixed Oxide Nanoparticles (NPs) of Manganese with Iron and Cobalt. The well characterized (TEM, EDX, XRD) catalysts were tested with respect to the relation of crystal structure to electrocatalytic activity and stability for the OER in alkaline media using Rotating Disk Electrode (RDE) measurements. We report a non-linear relation between composition and activity as well as durability.
Literature:
[1]Bergmann, A.; Martinez-Moreno, E.; Teschner, D.; Chernev, P.; Gliech, M.; de Araujo, J. F.; Reier, T.; Dau, H.; Strasser, P. Nat Commun 2015, 6.;
[2]Gliech, M.; Bergmann, A.; Spöri, C.; Strasser, P. Journal of Energy Chemistry 2016.
Nano-Surface Finishing for Electrothermal Instability Evolution Studies
Authors: Yelton W. Graham , Awe T.J. , Pillars Jamin Ryan , Yu E.P. , Peterson K.J. , Rosenthal S.E. , Sinars D.B. , Gomez M.R. , Vesey R.a. , Yates K.C. , Bauer B.S. , Hutchinson T .M. , Fuelling S. 
Published: February 2020

Implosion asymmetries generated by the Magneto-Rayleigh-Taylor (MRT) instability commonly limit the performance of the magnetically accelerated targets used to compress high-energy-density plasmas for radiation effects sciences and inertial confinement fusion studies, yet the seed perturbation from which MRT grows is not yet fully understood. Early in the current pulse an electrothermal instability (ETI), which is driven by non-uniform runaway Ohmic heating, may provide a mass perturbation on the target’s surface which exceeds the machining roughness; ETI may then provide the dominant seed from which MRT grows.
First, surface finishing data and results from experiments on the Sandia National Laboratories Z Machine (20 MA in 100 ns) are presented which measure the implosion stability of magnetically accelerated liners that were diamond machined and DC electropolished. Experiments examined Al 1100 and Al 2099 liners. High surface precipitates of aluminum, iron, and silicon where found in Al 1100 samples whereas Al 2099 samples show surface precipitates rich in copper after DC electropolishing. While the targets used for Z experiments are typically diamond turned to 10-30 nm rms surface roughness, the observed MRT amplitude is unexpectedly large. Second, surface finishing data and results from experiments on the U. of Nevada, Reno Zebra Facility (1 MA in 100 ns) are presented. These experiments studied the non-uniform heating of high-purity Al 5N, and Al 6061. When intensely Ohmically heated, Al 6061 alloy, which contains distributed non-metallic inclusions, forms 2-3 times as many surface hot spots as 99.999% pure 5N Al rods (with no inclusions). Various surface finishes were studied, including “as-received” machined, diamond turned, and electropolished post-finished. All post-finishes required a two-step “onion-skin” approach to remove nano layers of material at a uniform rate across a large scale. This approach involved pulse anodizing the targets to form an oxide favoring high ridges created by the cutting tools. Next, the oxide was selectively removed to the aluminum substrate. After removing the oxide, the targets were pulse nano-electropolished using chemistries precisely tailored to the alloy. After the nano-electropolishing step, surface profiles were optically characterized using 3D interferometry. The “post-finish” process was repeated until machining defects were minimized.
This work was funded in part by Sandia’s LDRD program. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.
(Invited) Photocatalytic CO2 reduction with Water By Cu/TiO2: Mechanistic Studies Using in Situ XAS and FTIR
Authors: Liu Lianjun , Miller Jeffrey , Li Ying 
Published: February 2020

Cu/TiO2 photocatalysts are extensively studied for CO2 photoreduction with H2O, but the roles of Cu species and the photocatalyst deactivation mechanism are not well understood. In this work, we have employed in situ X-ray absorption spectroscopy (XAS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), to explore the surface chemistry of various Cu/TiO2 under CO2 photoreduction environment. We found that H2 reduced Cu/TiO2 exhibited 50% higher activity of CO production than air-calcined Cu/TiO2, resulting from the synergy of OH groups, Cu+ and oxygen vacancies that can provide CO2 adsorption sites, act as hole scavengers, and facilitate the activation of adsorbed CO2. Meanwhile, the consumption of OH groups and Cu+ active sites by holes may result in catalyst deactivation, correlated to the change of oxidation state from Cu+ to Cu2+ and increased coordination number. Strategies to maintain the more active Cu+ species for more stable CO2 photoreduction activity is also discussed.
Non-Precious Metal-Catalyzed Photoelectrodes for Hydrogen Production Via Solar Water Splitting
Authors: Hellstern Thomas R , DeAngelis Alexander D , King Laurie Ann , Chakthranont Pongkarn , Britto Reuben J , Gaillard Nicolas , Jaramillo Thomas F 
Published: February 2020

Photoelectrochemical (PEC) water splitting is a promising route for synthesizing hydrogen using solar energy without direct CO2 emissions.[1] Recent performance modelling studies have shown that systems consisting of two semiconducting electrodes can achieve higher efficiencies than single absorber configurations.[2]

Copper gallium diselenide (CGSe) is a promising wide band gap absorber material for application in a tandem PEC device due to its near-ideal band gap, relatively low cost, and good minority carrier transport.[3] Recent studies involving CGSe as a wide band gap photocathode and platinum as a co-catalyst have shown promising activity but limited stability in alkaline electrolyte.[4] However, many opportunities remain to improve the stability and scalability of these electrodes by improving corrosion resistance and incorporating earth abundant catalysts. Recently, excellent electrochemically stable and earth abundant catalysts, molybdenum disulfide and cobalt phosphide, have emerged as viable alternatives to platinum for catalyzing the hydrogen evolution reaction.[5]
[6]

In this work, we discuss our progress in synthesizing transition metal sulfide and phosphide films that provide corrosion resistance and catalyze the hydrogen evolution reaction for a variety of PEC water splitting electrodes including CGSe and silicon. First, we explore the challenges inherent to protecting different classes of semiconductor materials including topological and processing constraints. These challenges are overcome by using atomic layer deposition combined with low temperature sulfidation and phosphidation as an effective route to synthesizing stable, low light absorbing, broadly applicable thin film catalysts for use in PEC water splitting. Next, we discuss techniques for bridging the gap in hydrogen evolution activity between precious and non-precious metal catalysts. Finally, we suggest general strategies for maximizing device performance of non-precious metal catalyzed solar water splitting electrodes.
[1] M. G. Walter, E. L. Warren, J. R. McKone, S. W. Boettcher, Q. X. Mi, E. A. Santori, N. S. Lewis, Chem. Rev. 2010, 110, 6446.
[2] L. C. Seitz, Z. Chen, A. J. Forman, B. A. Pinaud, J. D. Benck, T. F. Jaramillo, ChemSusChem 2014, 7, 1372.
[3] B. Marsen, B. Cole, E. L. Miller, Solar Energy Materials and Solar Cells 2008, 92, 1054.
[4] M. Moriya, T. Minegishi, H. Kumagai, M. Katayama, J. Kubota, K. Domen, Journal of the American Chemical Society 2013, 135, 3733.
[5] T. R. Hellstern, J. D. Benck, J. Kibsgaard, C. Hahn, T. F. Jaramillo, Adv. Energy Mater. 2016, 6.
[6] J. D. Benck, S. C. Lee, K. D. Fong, J. Kibsgaard, R. Sinclair, T. F. Jaramillo, Advanced Energy Materials 2014, 4.
Recent Progress in Aqueous Organic Flow Batteries
Authors: Lin Kaixiang , Chen Qing , Beh Eugene S. , Gerhardt Michael R. , Wong Andrew A. , Tong Liuchuan , Bombarelli Rafa Gómez , Marshak Michael P. , Gordon Roy G. , Aspuru-Guzik Alan , Aziz Michael J. 
Published: February 2020

Aqueous-soluble redox-active organic molecules such as quinones are potential low-cost alternatives to metal-based redox flow battery (RFB) chemistries, as demonstrated by a high-performance quinone-hydrobromic acid RFB [1-3]. Here we report the performance of new RFBs based on alkaline chemistries that are non-toxic and less corrosive than the acidic chemistry reported earlier. One cell utilizes 2,6-dihydroxy anthraquinone, which is stable and soluble in KOH, as the negolyte, coupled with ferri/ferrocyanide as the posolyte (Fig. 1, top) [4]. Others introduce RFBs to new classes of redox-active organics other than quinones, including one with a simple, single-step low-cost synthesis with good yield, which exhibits extremely high solubility and operates in a cell (Fig. 1, bottom) with >99.98% capacity retention per cycle.
Fig. 1. Top: CV and cell performance for 2,6-DHAQ vs ferri/ferrocyanide alkaline RFB, from [4]. Bottom: CVs and cell performance for very inexpensive non-quinone RFB.
[1] B. Huskinson et al., Nature
505, 195 (2014).
[2] Q. Chen et al.,
J. Electrochem. Soc.
163, A5010 (2016).
[3] Q. Chen et al.,
J. Electrochem. Soc.
163, A5057 (2016).
[4] K. Lin et al.,
Science
349, 1529 (2015).

Figure 1
Design and Optimization of Carbon Foam Electrode for Local Confinement of Bromine in Non-Flowing Single-Chamber Zinc Bromine Batteries
Authors: Biswas Shaurjo , Senju Aoi , Hodson Thomas , Yang Xiaofang , Koel Bruce E. , Steingart Daniel A 
Published: February 2020

Zinc Bromine redox flow batteries are well studied, quite inexpensive, and have reasonably high power and energy densities. However, there has been limited commercial implementation of bromine bearing systems in general, and the Zn-Br2 systems in particular, due to the following premises: i) Br2(l), generated at the cathode during charging, can diffuse through the electrolyte and react with Zn deposited at the anode (crossover), leading to self-discharge; ii) Repeated electroplating and dissolution of zinc leads to dendrite formation, which can form a conductive bridge between the electrodes (shorting), and iii) Br2(l) has low miscibility in aqueous solutions (~2.8 vol%) and tends to stratify, resulting in non-uniform concentration distributions. Standard Zn-Br2 flow-cell designs alleviate these limitations with bromine-complexing agents to improve Br2(l) solubility, separation membranes to prevent crossover and shorting, and flowing electrolyte to remove bromine and to minimize dendrite formation.
In the membrane-free, non-flowing single-chamber zinc-bromine (SC-Zn-Br2) battery design zinc dendrites are allowed to form freely and Br2(l) is allowed to stratify; expensive membranes, complexing agents, and pumps are eliminated; and yet overall energy efficiency is improved and cost is lowered. This is achieved by using a highly-porous carbon foam electrode (CFE) for local containment of Br2 generated during cycling, thus preventing crossover. Zinc dendrites are allowed to grow, but react with the highly corrosive Br2(l) on the surface of the CFE and dissolve back into the electrolyte as Zn2+ and Br-ions. This prevents shorting.
Here, we discuss the design, composition, and fabrication of the CFE, and its effects on the performance of SC-Zn-Br2 battery. In particular, we demonstrate the optimization of CFE porosity through processing parameters to maximize the coulombic and energy efficiencies of the cell. We also introduce a color tracking and feedback monitoring scheme to actively control the active species (deep red Br2(l), yellow Br2(aq), and colorless ZnBr2 electrolyte) transport and prevent self-discharge. Finally, we demonstrate the effect of prolonged exposure to Br2(l) after multiple cycles on various CFE compositions using XPS analysis, and the potential degradation mechanisms. We show coulombic and energy efficiencies of 95% and 75%, respectively, for over 1000 cycles for SC-Zn-Br2 cells, with improvements possible with further optimization of the CFE.
Ultrafine Nb2O5 Nanocrystal Coating on Reduced Graphene Oxide As Anode Materials for Sodium Ion Battery
Authors: Yan Litao , Chen Gen , Luo Hongmei 
Published: February 2020

Sodium ion battery (SIB) is a promising candidate for large-scale and practical application because of its lower costs and widespread of sodium resource.1 However, for SIBs, the intrinsic difference between sodium and lithium (ca. 55% larger and 330% heavier) lead to slower kinetics and lower energy densities.1 Nevertheless, it is reported that the enhance SIBs performance could be obtained by introducing the proper sodium host.2 For example, recent advances indicated that the ordered mesoporous Nb2O5-C delivered a reversible capacity of ~175 mA h/g and excellent cycle stability (up to 300 cycles).3 However, the low rate performance (<100 mA h/g at rate of 1A/g) cannot meet the requirements of fast charge-discharge electrochemical devices.
In this work, ultrafine Nb2O5 nanocrystal/reduced graphene oxide (Nb2O5/rGO) was demonstrated as a promising anode material for sodium ion battery with high rate performance and high cycle durability. The Nb2O5/rGO was synthesized by controllable hydrolysis of niobium ethoxide and following treated at high annealing temperature in forming gas. Transmission electron microscopy (TEM) showed that ultrafine Nb2O5 nanocrystal with average particle size of 3 nm was uniformly deposited on rGO. Highly conductive rGO network and ultrafine Nb2O5 not only can enhance charge transfer and buffer the volume change during sodiation/desodiation process, but also could provide more active surface area for sodium ion storage, resulting in superior rate performance and cycle performance. XPS and XRD analyses revealed that the sodium ion storage mechanism in Nb2O5 could be accompanied with Nb5+/Nb4+ redox reaction and the ultrafine Nb2O5 nanocrystal provide more surface area to finish the redox reaction.

Reference:

1. N. Yabuuchi, K. Kubota, M. Dahbi and S. Komaba, Chemical Reviews, 2014, 114, 11636-11682.
2. Y.-U. Park, D.-H. Seo, H.-S. Kwon, B. Kim, J. Kim, H. Kim, I. Kim, H.-I. Yoo and K. Kang, Journal ofthe American Chemical Society, 2013, 135, 13870-13878.
3. H. Kim, E. Lim, C. Jo, G. Yoon, J. Hwang, S. Jeong, J. Lee and K. Kang, Nano Energy, 2015, 16, 62-70.
Divalent Tin Oxide (SnO) Carbon Composite As Superior Anode in Sodium-Ion Batteries
Authors: Zhou Dehua , Johnson Christopher 
Published: February 2020

In the sodium system, perhaps the greatest technical hurdle to overcome is the lack of a high-performance anode material, which has good capacity, is easy to synthesize, safe, non-toxic and is low cost. The opportunity in this area is to develop a new anode material that meets all of these criteria. To date there are a handful of examples in the literature that show the chemistry and battery performance of ambient temperature sodium ion battery anodes. Most of these are various carbon materials, Sn, Sb or SnSb, intermetallics, and sodium titanium oxides, but for one reason or another many of these fall short of all the attributes needed.
Our approach is to develop novel oxygen-containing intermetallic nanocomposite anodes with a high surface area/volume ratio that includes a specially tailored cocktail of individual elements and intermetallic phases to enable sequential electrochemical reactions that are designed to reduce the volume expansion while increasing the volumetric capacity. In this case we have been developing a carbon composite consisting of semi-conducting divalent tin oxide (SnO). In the case of a conversion reaction and then sodiation of expelled Sn, then the irreversible capacity will be lower than for SnO2 due to the smaller amount of oxygen in the system. In fact we have synthesized an attractive anode system for sodium-ion batteries (SIBs) that consists of SnO_C made by high-energy ball milling simply carbon with commercially available SnO. Figures 1a and 1b show the voltage profiles of the first two cycles, and the capacity with cycle numbers. The results demonstrate the viability of this material as an anode for SIBs. This material and its detailed in operando X-ray characterization will be discussed at the talk.

Figure 1. (a) First two voltage profiles of Na/SnO_C composite SIB anode. Note the low first cycle irreversibility capacity loss; (b) capacity and coulombic efficiency over 35 cycles.

Acknowledgements

This work is supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.

Figure 1
Diffusion Measurements of Mg in High Capacity Thiospinel MgxTi2S4
Authors: Bonnick Patrick , Sun Xiaoqi , Nazar Linda F 
Published: February 2020

The demand for smaller batteries capable of storing the same amount of energy as conventional Li-ion technology has led to the pursuit of several new technologies including rechargeable Mg batteries. Mg metal is attractive as a negative electrode material because it has a higher volumetric capacity density (3833 mAh/mL) than Li metal (2062 mAh/mL), is the 8th most abundant element in the earth’s crust, is safe to handle in ambient atmosphere, and can be electrodeposited (charged) without the formation of dendrites.1 The seminal work by Aurbach et al. in 20002 established an electrolyte and a positive electrode material, the Chevrel phase (Mo6S8), that was paired with Mg metal to form the first rechargeable Mg battery.
Mg2+ intercalation in host materials is more difficult than that of Li+ or Na+, displaying lower ion mobility in solid oxide hosts3 and a probable higher desolvation energy penalty.4 No further positive electrode materials with both notable capacity and cycle life have been demonstrated since the Chevrel phase, until now. In this presentation, we will demonstrate that the thiospinel Ti2S4 reversibly intercalates Mg2+ with a 2ndcycle capacity of about 165 mAh/g, which drops to only 140 mAh/g after 40 cycles at C/10 as shown in Figure 1.
Of crucial scientific importance is that Ti2S4 provides a second example of a material that supports facile Mg2+ diffusion, which could help elucidate why Mg2+ intercalation is so difficult in other potential cathode materials. In exploring Mg2+ diffusion, the first step is to measure the chemical diffusion coefficient, D. The galvanostatic intermittent titration technique (GITT)5 is a versatile method of carrying this out for an intercalant like Mg2+ if a reliable cell can be constructed that has a long enough diffusion length to produce a linear potential vs time response reflecting Fick’s laws of diffusion. Figure 2 shows a typical GITT experiment on thiospinel MgxTi2S4, which displays the required potential vs time response. This talk will elaborate on the results of the diffusion measurements we have performed and compare those results to theory.

References

J. Muldoon, C. B. Bucur, and T. Gregory. Chem. Rev.
114, 11683-11720 (2014).

D. Aurbach, Z. Lu, A. Schechter, Y. Gofer, H. Gizbar, R. Turgeman, Y. Cohen, M. Moshkovich and E. Levi. Nature
407, 724-727 (2000).

E. Levi, Y. Gofer, and D. Aurbach. Chem. Mater.
22, 860-868 (2010).

L. F. Wan, B. R. Perdue, C. A. Apblett and D. Prendergast. Chem. Mater.
27, 5932-5940 (2015).

W. Weppner and R. A. Huggins. Solid-State Science and Technology
124, 1569-1578 (1977).

Figure 1
First-Principles Screening and Evaluation of Sulfide Compounds for Multivalent Battery Cathode Applications
Authors: Liu Miao , Rong Ziqin , Canepa Pieremanuele , Malik Rahul , Jain Anubhav , Ceder Gerbrand , Persson Kristin A 
Published: February 2020

The rapid growth of portable consumer electronics and electric vehicles demands new battery technologies with greater energy stored at a reduced cost. Energy storage solutions based on multivalent metals, such as Mg, could significantly increase the energy density as compared to lithium-ion based technology. In this work, we use recent advances in high-throughput first-principles calculations to systematically evaluate the performance of a group of 3d transition-metal sulfide compounds for multivalent cathode applications. We estimate the insertion voltage, capacity, thermodynamic stability of charged and discharged states, as well as the intercalating ion mobility and use these properties to evaluate promising directions. From our calculations, we identified sulfide compounds that exhibit improved Mg2+ mobility with feasible low diffusion activation energy; lower than their oxide counterparts, however the improved mobility comes at the expense of lower voltage and thereby lower theoretical specific energy. We also identified a Ca2+ intercalating sulfide compound which exhibits a low diffusion activation barrier of ~500 meV and a voltage of ~2V, revealing a potential cathode for use in Ca ion rechargeable batteries. We also present several general trends and design insights extracted from our evaluation for this category of materials.