<rss xmlns:a10="http://www.w3.org/2005/Atom" version="2.0"><channel><title>EFRCs Science Highlights</title><link>http://science.energy.gov/bes/efrc/highlights/</link><description>The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, providing more than 40 percent of total funding for this vital area of national importance. It oversees - and is the principal federal funding agency of - the Nation's research programs in high-energy physics, nuclear physics, and fusion energy sciences.</description><language>en</language><item><guid isPermaLink="false">{4DABE467-3780-4FDA-88D2-7B004B0ECE96}</guid><link>http://science.energy.gov/bes/highlights/2013/bes-2013-02-a/</link><title>Making the Right Substitution for Better Thermoelectrics</title><description>&lt;img src='/~/media/C7B16C93B72C4DA895FFCD6323806573.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Exploiting the self-organizing nature of atoms to block heat transfer and improve thermal-to-electrical energy conversion.</description><pubDate>Fri, 10 May 2013 11:13:34 -0400</pubDate><a10:content type="html">&lt;p&gt;Like a coach in sports, making the right substitution can make the difference between winning and losing. Using a combination of theory and simulations, the researchers at the University of Michigan EFRC predicted that replacing some of the antimony (Sb) atoms in the skutterudite mineral, cobalt antimonide (CoSb&lt;sub&gt;3&lt;/sub&gt;), would disrupt the atomic vibrations that play a crucial role in transferring heat through the material &amp;ndash; but only if the replacement atoms took up specific atomic locations in the crystal structure. Quantum mechanical calculations were used to predict that entire 4-member rings of Sb atoms (Sb4) would be replaced by cross-diagonal rings of Ge&lt;sub&gt;2&lt;/sub&gt;Te&lt;sub&gt;2&lt;/sub&gt; due to the natural, atomic ordering tendencies of alloying elements. The consequences of this substitution order on the atomic vibrations responsible for heat transfer was verified by molecular dynamic simulations and then experimentally demonstrated by measuring the reduction in the thermal conductivity for the substituted material CoSb&lt;sub&gt;3(1-x)&lt;/sub&gt;Ge&lt;sub&gt;1.5x&lt;/sub&gt;Te&lt;sub&gt;1.5x&lt;/sub&gt;. This approach and resulting insights can be extended to other families of thermoelectric materials to reduce the thermal conductivity of these materials and increase the efficiency of heat-to-electricity conversion for thermoelectric devices.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{C0AB145B-3B67-4B29-987A-C745A176A198}</guid><link>http://science.energy.gov/bes/highlights/2013/bes-2013-02-b/</link><title>Nano-Composite Designs for Energy Storage</title><description>&lt;img src='/~/media/DCE164BCA2684EA89EDA0C6A53141472.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Nano-porous metal oxide coatings on carbon fiber dramatically enhance the electrical storage capacity for supercapacitors.</description><pubDate>Fri, 10 May 2013 11:13:35 -0400</pubDate><a10:content type="html">&lt;p&gt;Pseudocapacitors are supercapacitors that store electrical charge both like a capacitor (with the normal electrostatic double layer of charges at the electrode-electrolyte interface) and like a battery (with multiple chemical reaction mechanisms involving charge transport across the electrode-electrolyte interface).&amp;nbsp; Metal oxides such as cobalt or manganese oxide (C&lt;sub&gt;o3O4&lt;/sub&gt; or MnO&lt;sub&gt;2&lt;/sub&gt;) store pseudocapacitive charge via metal ions which change oxidation state (e.g., Mn&lt;sup&gt;+3&lt;/sup&gt; &lt;span style="line-height: 115%; font-family: symbol; color: #363636; font-size: 10pt;"&gt;&amp;Ucirc;&lt;/span&gt; Mn&lt;sup&gt;+4&lt;/sup&gt;) as a result of the charge transfer.&amp;nbsp;Researchers at the Energy Frontier Research Center on Heterogeneous Functional Materials, the &amp;ldquo;HeteroFoaM Center,&amp;rdquo; have discovered how the relative sizes, shapes, atomic arrangements and interfaces of the materials in psuedocapacitors control the amount of charge that can be stored and even the mechanisms of charge storage.&amp;nbsp;In fact, the electrochemical storage properties are not limited by the properties of the materials and can be radically different if the &amp;ldquo;heterogeneity&amp;rdquo; of the composite material is understood and optimized. For example, as-deposited MnO&lt;sub&gt;2&lt;/sub&gt; on conductive carbon fiber showed high specific capacitance (333 F/g) due to psuedocapacitance of the manganese ions, but conversion of the material through heat treatment to a different heterogeneous arrangement &amp;ndash; a mixed-valence, nano-porous MnOx coating &amp;ndash; dramatically enhanced storage capacity, achieving very high specific capacitance (~2,500 F/g) while maintaining excellent power density (~98 kW/kg at ~122.7 A/g).&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{A1F1F429-A46A-4970-9BC3-853158E1144B}</guid><link>http://science.energy.gov/bes/highlights/2013/bes-2013-02-c/</link><title>Understanding Nature’s Choreography in Batteries</title><description>&lt;img src='/~/media/214E9D85FBC64973AC4D23F2E487EF31.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Charge-discharge chemistry for lithium ion batteries elucidated by theoretical calculations.</description><pubDate>Fri, 10 May 2013 11:13:35 -0400</pubDate><a10:content type="html">&lt;p&gt;Ethylene carbonate (EC) electrolytes and manganese spinel (Li&lt;sub&gt;x&lt;/sub&gt;Mn&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;) positive electrodes are commonly used in lithium ion batteries.&amp;nbsp;A comparison of the electrochemical potentials of EC and bulk Li&lt;sub&gt;x&lt;/sub&gt;Mn&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt; suggests that decomposition of the electrolyte would not occur directly by electrons being transferred from EC to the electrode material, but the surface of a solid can have very different properties than its interior bulk.&amp;nbsp;Researchers at Sandia National Laboratories, as part of the Nanostructures for Electrical Energy Storage (NEES) EFRC, have completed detailed coupled simulations of the molecules of the electrolyte and the surface of the positive electrode showing that the oxygen atoms on a Li&lt;sub&gt;0.6&lt;/sub&gt;Mn&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt; surface can deform and weakly bind the EC molecule when it is near the electrode surface. This initial interaction does not involve the transfer of electrons (i.e., oxidation) but does enable breaking of the carbon-oxygen bond and subsequent molecular rearrangements that result in two electrons and a proton being transferred to the electrode surface.&amp;nbsp; Therefore, a predicted series of five steps breaks down the electrolyte molecule, leaving the oxidized EC fragment still bound to the now acidified electrode surface.&amp;nbsp; Acidification of positive electrodes is widely believed to initiate corrosion of the electrode surface and possible dissolution of manganese atoms.&amp;nbsp;The proposed acidification mechanism&amp;nbsp;illustrates the importance of modeling the electrolyte and the electrode surface together.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{C6029213-9182-4952-B478-6CF336036F65}</guid><link>http://science.energy.gov/bes/highlights/2013/bes-2013-02-d/</link><title>Double the Charge from One Photon in Organic Photovoltaics</title><description>&lt;img src='/~/media/8E64780517404923909574AF5FA3CDB3.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;First observation of key intermediate state in the conversion of one photon to two electrons.</description><pubDate>Fri, 10 May 2013 11:13:36 -0400</pubDate><a10:content type="html">&lt;p&gt;Multiple exciton generation (MEG) refers to the creation of two or more pairs of charge carriers (electron-hole pairs known as excitons) from the absorption of one photon. Although MEG holds great promise for improving the efficiency of organic solar cells, it has proven challenging to implement.&amp;nbsp;Using a model system based on either pentacene or tetracene molecules deposited upon carbon fullerene bilayers, EFRC scientists have used femtosecond electron spectroscopy to directly observe a new multiexciton (ME) state ensuing from the absorption of a single photon in the molecular layer.&amp;nbsp;Data for both systems indicate that the ME state can decay into two separate excitons and that one electron can be transferred into the fullerene layer from each exciton.&amp;nbsp;For pentacene, two electrons can be directly transferred from the ME state to an adjacent fullerene layer on a sub-picosecond time scale, which is much faster than electron transfer from either of the two separate excitons from ME decay. In this mechanism, losses in photovoltaic efficiency due to unproductive decay or recombination of individual excitons can be avoided by directly extracting multiple electrons from the ME state at the fullerene surface.&amp;nbsp;Investigation of these processes has generated a new set of design principles for harvesting energy through multiple exciton generation in molecular systems.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{05856B6A-AE72-474E-953F-A3832973C074}</guid><link>http://science.energy.gov/bes/highlights/2013/bes-2013-02-e/</link><title>An Unexpected Heat Wave</title><description>&lt;img src='/~/media/330C7EBF533F46ACA50A13DC4DBE1D72.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Observation of wavelike heat conduction reveals new possibilities for tailoring thermal transport through wave effects.</description><pubDate>Fri, 10 May 2013 11:13:36 -0400</pubDate><a10:content type="html">&lt;p&gt;In many materials, thermal energy is transported by vibrations of the atomic lattice known as phonons. Similar to photons of light, these lattice vibrations can be treated as waves, but in most materials the phases of the phonon waves quickly randomize after interacting among themselves, with any imperfection or with any interface between two materials. This phase randomization means that the transport of heat becomes incoherent and difficult to predict or control. In this study, heat transport through superlattices (SL) made up of periodic stacks of semiconductor thin films was studied both experimentally and theoretically with a surprising result.&amp;nbsp;A novel experimental approach indicated that the wave properties of some heat-carrying phonons &amp;ndash; and their coherence &amp;ndash; could be maintained even with the presence of several material interfaces. Theoretical studies supported the experimental conclusions that the low frequency phonons traveled through the SL stack in coherent fashion as if the layered structure was a homogeneous material. This scientific discovery and modeling capability opens new pathways for controlling heat transfer through materials by tailoring the lattice waves at the nanostructure scale.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{F2744DB8-8FA0-490B-A031-44FEEA748952}</guid><link>http://science.energy.gov/bes/highlights/2013/bes-2013-01-a/</link><title>Mapping Subsurface CO2 Migration</title><description>&lt;img src='/~/media/1F6D9519A1064CCAA7E18958908C5C00.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;New computational technique creates high resolution maps of subsurface CO&lt;sub&gt;2&lt;/sub&gt; after geologic sequestration.</description><pubDate>Fri, 10 May 2013 11:13:34 -0400</pubDate><a10:content type="html">&lt;p&gt;A powerful new &amp;ldquo;seismic inversion&amp;rdquo; technique&amp;nbsp;&amp;nbsp;uses time-lapse seismic data to make high resolution images useful for evaluating subsurface migration of CO&lt;sub&gt;2&lt;/sub&gt; following geologic sequestration. Migration of CO&lt;sub&gt;2&lt;/sub&gt; alters the mechanical properties of porous rocks which can be monitored from high frequency rock property variations embedded in the seismic amplitude data. The technique utilizes a dictionary of seismic &amp;ldquo;wavelets&amp;rdquo;, information derived from seismic data before CO&lt;sub&gt;2&lt;/sub&gt; injection, and an optimization algorithm to identify the set of common wavelets that best describe the variations in seismic amplitudes observed pre- and post- CO&lt;sub&gt;2&lt;/sub&gt; injection. The University of Texas-Austin team applied it to investigate the migration pathways of the CO&lt;sub&gt;2&lt;/sub&gt; plume at the Cranfield, Mississippi field demonstration site where such time-lapse surface seismic surveys are available. The raw seismic data showed only a weak signature of CO&lt;sub&gt;2&lt;/sub&gt; injection. However, &amp;ldquo;seismic inversion&amp;rdquo; of the data enhanced the information content, showing that the injected CO&lt;sub&gt;2&lt;/sub&gt; migrated mostly along the top of the layer of rock into which it was injected, but there was no leakage through the reservoir seals. This technique affords an effective way to monitor potential leakage of CO&lt;sub&gt;2&lt;/sub&gt; plumes at various reservoirs.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{4F6D157B-62D3-4F1D-9FE8-CDF05730AE81}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-12-b/</link><title>Two for the Price of One: Water and Carbon Dioxide Splitting via a Single Catalyst</title><description>&lt;img src='/~/media/5A9D9A8DF1DF45FE8F45A41AC6B245E6.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;A simple, robust catalyst is capable of both water oxidation and carbon dioxide splitting, two difficult yet key reactions for solar energy conversion.</description><pubDate>Fri, 10 May 2013 11:21:36 -0400</pubDate><a10:content type="html">&lt;p&gt;In the field of artificial photosynthesis, solar fuels, generated by splitting water into hydrogen and oxygen or reducing carbon dioxide to carbon monoxide, methanol, or hydrocarbons, have great potential as alternative energy sources.&amp;nbsp; Such fuels could further solve an energy storage problem by allowing solar energy collected during the day to be stored and used at night.&amp;nbsp; A key challenge for solar fuel production is finding enough energy from sunlight to drive the complex water splitting oxidation and carbon dioxide reduction reactions. Researchers at the Solar Fuels EFRC at the University of North Carolina &amp;ndash; Chapel Hill made an important discovery &amp;ndash; a metal complex catalyst, a polypyridyl complex of ruthenium, catalyzed both water oxidation and carbon dioxide reduction. Using this catalyst, an electrochemical cell was developed that split carbon dioxide into carbon monoxide and oxygen.&amp;nbsp; As ruthenium is rare and expensive, a cheaper, more widely available alternative was needed; EFRC researchers discovered simple salts of copper (II), under the right conditions, react as robust electrocatalysts for oxidizing water. These results are an important step in developing a simple, highly effective approach for solar fuel production.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{CB72E74E-BDD2-4760-A131-59B125B51199}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-10-g/</link><title>Adding Nanocavities to Catalyst Surfaces Enhances Chemical Selectivity</title><description>&lt;img src='/~/media/6B32687020B641409FBF1A56CEF64097.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Adding an oxide sieve, a layer containing nanocavities, to a catalyst surface makes the catalyst selective for specific reactions and increases efficiencies for chemical processes.</description><pubDate>Fri, 10 May 2013 11:21:35 -0400</pubDate><a10:content type="html">&lt;p&gt;Catalysts are compounds that enhance the speed of chemical reactions in a wide range of industrial chemistry applications. The Institute for Atom-Efficient Chemical Transformation (IACT), a DOE-supported Energy Frontier Research Center (EFRC), is developing new reactions and new catalytic materials for bioenergy production by combining advanced characterization, computer simulations, and materials synthesis.&amp;nbsp;IACT researchers at Northwestern University and Argonne National Laboratory developed a new technique to modify existing oxide catalysts with a surface film that enhances the selectivity of the catalyst. These films contain &amp;lt;2 nm diameter &amp;ldquo;nanocavities&amp;rdquo; made by adding a template during the atomic layer deposition process that is used to synthesize atom-precise films of oxides, metals, and other materials. Removal of the template after synthesis results in the nanocavities in the surface that provides a sieving effect, allowing separation of the reactant molecules and limiting reactions to a single particle. Because the thickness of the sieving layer is comparable in size to the reactant molecules, diffusional limitations that plague other materials are not present here. Ultimately, adding selectivity to intrinsically non-selective oxide catalysts is expected to decrease the cost for biofuels and bio-derived chemicals by decreasing the need for challenging and costly separations and increasing the product yields.&lt;/p&gt;
&lt;p&gt;The research utilized the Advanced Photon Source for characterization of the structures.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{7291F942-6029-42E7-A4ED-65057C685672}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-09-a/</link><title>Mimicking Photosynthesis for Production of Solar Fuels</title><description>&lt;img src='/~/media/FFCEEF8DB53E47E9847517FCB8BE469D.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;A step closer to an artificial system using sunlight to produce hydrogen from water</description><pubDate>Fri, 10 May 2013 11:21:34 -0400</pubDate><a10:content type="html">&lt;p&gt;In natural photosynthesis, multiprotein complexes termed photosystems capture solar energy and convert it to chemical energy.&amp;nbsp; Sunlight is absorbed by a pigment in the photosynthetic reaction center of the photosystem, causing electrons to increase in energy.&amp;nbsp; These high-energy electrons are then transported through a series of components to the water splitting/oxygen evolving complex in the photosystem where via the energy from the electrons, water molecules are split into oxygen and hydrogen ions. Using natural photosynthesis as a model, The Center for Bio-Inspired Solar Fuel Production EFRC at Arizona State University designed a completely artificial photosynthetic fuel production system.&amp;nbsp; Researchers constructed synthetic versions of each of the key parts of electron absorption and electron transfer found in a natural photosystem.&amp;nbsp; Ultrafast laser studies verified that the synthetic version functioned in a manner similar to the natural version. The water splitting/oxygen evolving component was added through collaboration with Pennsylvania State University.&amp;nbsp; When illuminated, the final completed solar water splitting device produces oxygen and hydrogen gas from water.&amp;nbsp; While this artificial system is inefficient and currently operated only on the laboratory scale, it is a step forward in finding a way to a viable solar fuel technology.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{D3D0CED3-F4E4-45D4-BC40-4B017CFC1F6E}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-09-b/</link><title>New Catalytic Approach Builds Molecules with Specific Functionality More Safely and Efficiently</title><description>&lt;img src='/~/media/F1C03600DBEB4CA2853A1A63AD3D4EFA.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Rapid creation of carbon-fluorine bonds may lead to improved production of drugs, agrochemicals and positron emission tomography (PET) tracers.</description><pubDate>Fri, 10 May 2013 11:21:35 -0400</pubDate><a10:content type="html">&lt;p&gt;Catalysts for low-temperature and selective substitution of bonds in hydrocarbons to produce specific functionality are central to the development of advanced technologies that can provide dramatic improvements in the utilization of energy. The Center for Catalytic Hydrocarbon Functionalization (CCHF), a DOE funded Energy Frontier Research Center, is developing efficient catalysts for conversion of hydrocarbons into higher value materials. CCHF researchers at Princeton University and the California Institute of Technology discovered a manganese porphyrin catalyst (lower left molecule in figure) that selectively fluorinates carbon-hydrogen bonds under mild conditions using simple fluorides.&amp;nbsp;The new fluorination system can be applied to a variety of alkanes, terpenoids and steroids&amp;mdash;industrial molecules that are used in agriculture, pharmaceutical production, and medical positron emission tomography (PET) scan tracers.&amp;nbsp;The yields of the reaction are sufficiently high and the techniques are sufficiently simple that the reaction can be performed without specialized apparatus.&amp;nbsp; Given that the source of F in this one-step, one-pot protocol is fluoride ion, applications to incorporate isotopically-labeled F into a wide variety of biomolecules and synthetic building blocks can be expected. &lt;/p&gt;
&lt;p&gt;A patent application has been filed on the methodologies and resulting catalysts.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{69410B29-B4B8-422B-9909-BD007580F9D5}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-08-a/</link><title>New Superhard Form of Carbon Dents Diamond</title><description>&lt;img src='/~/media/A7C71133E9E44C73BDB4C360EDFEF132.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Squeezing creates new class of material built from clusters of carbon atoms.</description><pubDate>Fri, 10 May 2013 11:21:34 -0400</pubDate><a10:content type="html">&lt;p&gt;How do you dent diamond, one of the Earth&amp;rsquo;s hardest materials? Researchers supported by the Energy Frontier Research in Extreme Environments EFRC&amp;nbsp;created a new substance that can do just that. To make the new material, the researchers started with &amp;lsquo;buckyballs,&amp;rsquo; soccer-ball shaped cages composed of sixty carbons, and mixed them in a liquid solvent called xylene.&amp;nbsp; The molecules of xylene served to &amp;ldquo;link&amp;rdquo; the buckyballs together in a regular, crystalline pattern like beads on a string. Finally, they squeezed the mixture in a diamond anvil cell in-situ in the synchrotron beam of the Advanced Photon Source. &amp;nbsp; Something extraordinary happened around 320,000 times atmospheric pressure; the buckyballs collapsed and formed disordered, amorphous clusters but the xylene molecules held fast and still tethered the amorphous pieces together in a pattern like before. The resulting, never-before-seen structure was surprisingly hard; strong enough to dent the diamond anvil. The material stayed in the same structure even after the pressure had been released, which makes it potentially useful for a variety of different devices, especially future electronics. (&lt;a href="/news/in-focus/2012/08-27-12/"&gt;Excerpt from DOE-SC's "In&amp;nbsp;Focus"&lt;/a&gt;)&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{C85B942E-043A-4E98-9C4B-B09786ECD2D4}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-07-b/</link><title>Underground Storage of Carbon Dioxide&amp;mdash;as a Solid </title><description>&lt;img src='/~/media/34DCFCF74E5649CDA7424992D2865AA9.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Nanoscale features in rocks enable more carbon dioxide to be trapped as a solid carbonate material underground.</description><pubDate>Fri, 10 May 2013 16:30:03 -0400</pubDate><a10:content type="html">&lt;p&gt;Advanced experiments and computations have shown that underground carbonate mineral nucleation and growth is strongly dependent on nanoscale features such as the pore structure and surface topography of permeable rocks and the interfacial energies between rock surfaces and solid carbonates. This research at the Lawrence Berkeley National Laboratory&amp;rsquo;s Center for Nanoscale Control of Geologic CO&lt;sub&gt;2&lt;/sub&gt;, Washington University in St. Louis, and Oregon State University provides the quantitative parameters necessary to develop advanced models that describe how nucleation and growth of carbonate occur in porous media that contain multiple minerals with different surface properties and micro- to nanoscale pores. In carbon capture and storage, CO&lt;sub&gt;2&lt;/sub&gt; is captured from power plant exhaust and other sources and injected underground into porous rock formations where it mixes with ambient salt water and may remain for 1000&amp;rsquo;s of years. Although it is expected that CO&lt;sub&gt;2&lt;/sub&gt; can be transformed to carbonate minerals, it is unknown how fast this will occur and how the addition of new carbonate mineral in the rock formations will affect the short and long-term behavior of the system. This research will enable more realistic modeling of mineral formation from the injected CO&lt;sub&gt;2&lt;/sub&gt; and thus increase the pace of deployment of this critical energy technology.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{9F31DFD5-71FD-4EB0-9ACC-7B6A2E1E5E79}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-06-a/</link><title>Simple Synthesis of Pore Highways Inside of Catalysts</title><description>&lt;img src='/~/media/bes/images/highlights/2012/06/ccei-thumb.jpg' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;House-of-Cards structure leads to improved zeolite catalyst.</description><pubDate>Mon, 18 Mar 2013 10:16:57 -0400</pubDate><a10:content type="html">
		&lt;p&gt;Increasing demand for energy and materials has led to an accelerated research effort in the development of renewable chemicals for a sustainable economy. Efforts within the Catalysis Center for Energy Innovation (CCEI), a DOE-funded Energy Frontier Research Center (EFRC), are aimed at realizing novel catalytic processes for production of chemicals and fuels from biomass-derived feedstocks by bridging catalyst design, reaction engineering and fundamental understanding of reaction mechanism. The researchers used a novel and simple synthesis technique, called repetitive branching, to stack the thin zeolite sheets at right angles generating a "house-of-cards" shaped crystal. By creating zeolite crystals with large-pore "highways," which are about 10 times bigger than the zeolite pores, chemicals and molecules can pass rapidly through the channels to reach the smaller, reactive pores within the crystal. This results in faster, more selective, and more stable catalysts, produced at the same cost as traditional zeolite catalysts. Research was performed at the University of Minnesota and has been licensed to Argilex.&lt;/p&gt;
</a10:content></item><item><guid isPermaLink="false">{5C548C32-C0EB-4655-8D37-EE34E68CEA69}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-05-a/</link><title>Low-Cost, Third Generation Solar Cells on Solid Ground</title><description>&lt;img src='/~/media/938DFCA0F40548D0A12A91F3E7F75E67.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Novel, liquid-less design promises to improve long-term stability and durability of dye-sensitized solar cells while hitting high efficiency marks.</description><pubDate>Fri, 10 May 2013 11:21:32 -0400</pubDate><a10:content type="html">&lt;p&gt;Current solar cell technologies are largely constrained by high production costs, low operating efficiency, and limited durability.&amp;nbsp;A low-cost alternative to current silicon-based solar cell devices are thin film solar cells, such as dye-sensitized solar cells (DSSCs). DSSCs are made up of inexpensive, environmentally-benign titanium dioxide nanoparticles coated with light-absorbing dye molecules, and a liquid electrolyte.&amp;nbsp; Research by the Argonne Northwestern Solar Energy Research (ANSER) EFRC at Argonne National Laboratory and Northwestern University has solved long-standing corrosion and durability problems associated with the liquid electrolyte. The corrosive, volatile liquid was replaced with a novel semiconducting inorganic solid, resulting in a solar cell that has competitive conversion efficiencies (10%) while withstanding high temperatures, high levels of humidity, and accelerated aging tests.&amp;nbsp;The solid semiconductor consisting of cesium tin iodide (CsSnI&lt;sub&gt;3&lt;/sub&gt;) can be processed in solution, an appealing characteristic for keeping manufacturing costs low.&amp;nbsp;The semiconductor also enhances light absorption of the DSSC in the red region of the solar spectrum, thereby outperforming conventional DSSCs. This discovery could lead to new solar cells that are both longer-lasting and highly efficient, while costing less to manufacture.&amp;nbsp;A patent has been filed for this development.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{55E59475-DA49-4A22-8B96-502CFFED2AAB}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-05-b/</link><title>Can Magnetism Explain High Temperature Superconductivity?</title><description>&lt;img src='/~/media/ADEC60372B184F41957E860AF1A0A46C.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Visualization of electron pair binding confirms predictions about how high temperature superconductivity works.</description><pubDate>Fri, 10 May 2013 11:21:33 -0400</pubDate><a10:content type="html">&lt;p&gt;By measuring how strongly electrons are bound together, forming &amp;ldquo;Cooper pairs&amp;rdquo;, in an iron-based superconductor, scientists at the Center for the Emergent Superconductivity Energy Frontier Research Center, Brookhaven National Laboratory, Cornell University, and St. Andrews University, with materials developers at AIST in Japan, provide direct evidence that magnetism holds the key to this material&amp;rsquo;s ability to carry current with no resistance. Several groups of theorists had hypothesized that if the electrons in a superconductor have their magnetic moments pointing in opposite directions, they could overcome their mutual repulsion to join forces in so-called Cooper pairs &amp;mdash; thus carrying current with no loss. According to the theory, the strength of the &amp;lsquo;glue&amp;rsquo; holding electron pairs together would be different for specific electrons and depend on the direction that the electrons are traveling &amp;mdash; with the pairing usually being stronger in a given direction than at 45&amp;deg; to that direction.&amp;nbsp;The researchers figured out how to measure the predicted direction dependence (anisotropy) in the energy necessary to unbind a pair by using a specially developed application of scanning tunneling microscopy. Their novel method, known as &amp;ldquo;multi-band Bogoliubov quasiparticle scattering interference,&amp;rdquo; discovered the anisotropic pairing &amp;ldquo;signature&amp;rdquo; predicted for three electronic bands of a model superconductor, lithium iron arsenide.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{6FF27E78-51A2-4D7A-AB5A-B3F57FD6CE24}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-05-c/</link><title>Electrical Energy Storage Using Carbon Slurries</title><description>&lt;img src='/~/media/CE7DE7FE393341C3A794087E1FBBCA97.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;New scalable, high power energy storage possible with carbon-electrolyte slurries.</description><pubDate>Fri, 10 May 2013 11:21:33 -0400</pubDate><a10:content type="html">&lt;p&gt;Scientists at Drexel University studying the properties of carbon slurries have discovered that the electrochemical and physical flow characteristics of such slurries are favorable for a new grid-scale storage concept called the electrochemical flow capacitor (EFC). In work supported by the Fluid Interface Reactions, Structures, and Transport (FIRST) Center, a DOE Energy Frontier Research Center, researchers have discovered that, just like supercapacitors, energy is stored in the electric double layer of charged carbon particles in an electrolyte slurry.&amp;nbsp;A flowable carbon-electrolyte slurry could serve as the active material for an EFC, in which the charged slurry is handled in a similar fashion to flow or semi-solid battery fluids (&lt;em&gt;i.e.&lt;/em&gt;, for charging/discharging, the slurry is pumped into an electrochemical cell; for energy storage, the charged slurry is pumped into reservoirs).&amp;nbsp;This new concept shares the major advantages of supercapacitors and flow batteries, providing rapid charging/discharging and excellent cyclability, while enabling the decoupling of the power and energy ratings. The study reported promising initial EFC performance data for carbon slurries obtained under static and intermittent flow operations. This approach may reduce the use of polymer separators, metal current collectors and packaging materials; these passive elements increase the cost and weight in current devices without contributing to the charge storage.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{529E0482-D5C8-4C16-B717-D41C8841134B}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-04-a/</link><title>There’s a Great Future in Plastic Solar Cells</title><description>&lt;img src='/~/media/4D01B398CDBB4AE990B70F0A936F03A4.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Researchers have created an environmentally-friendly plastic coating that converts a wide range of electrical conductors into air-stable components for flexible, less expensive electronics.</description><pubDate>Fri, 10 May 2013 11:21:31 -0400</pubDate><a10:content type="html">&lt;p&gt;Organic-based thin-film optoelectronics, such as solar cells, hold great potential as affordable consumer electronics. However, most printed optoelectronics require at least one electrode be a metal having a work function (the amount of energy needed to remove an electron) that is low enough to inject electrons into, or collect, electrons from an organic semiconductor. Unfortunately such metals are very reactive and easily oxidized, which reduces performance of the electrode.&amp;nbsp;To avoid this problem, a controlled fabrication environment and protective barrier are needed to prevent water and/or oxygen exposure, increasing manufacturing complexity and cost. Researchers at Georgia Tech, part of the Center for Interface Science: Solar Electric Materials (CISSEM) EFRC, discovered a universal approach, &lt;em&gt;i.e.,&lt;/em&gt; applicable to many materials, for producing a low work function electrode that is stable in air. By &amp;ldquo;sticking&amp;rdquo; (through physisorption) an ultrathin layer (1 to 10 nanometers) of a commercially available, environmentally-friendly polymer with amine-containing aliphatic chains to a wide range of conductor surfaces, an air-stable, high performance electrode was created.&amp;nbsp; To illustrate this approach&amp;rsquo;s promise, the researchers demonstrated, for the first time, a completely plastic organic solar cell on a flexible substrate, an approach that would lower manufacturing costs for solar cells and other electronics.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{EEAE22D1-6218-4B8B-A9D3-814187B558E5}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-04-b/</link><title>Improving Catalysis by Putting the Best Face Forward</title><description>&lt;img src='/~/media/BACC4E8B33E147C8A05600BC20173A58.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;New catalyst structures for fuel cells in vehicles improve activity and stability compared to commercial platinum counterparts.</description><pubDate>Fri, 10 May 2013 11:21:32 -0400</pubDate><a10:content type="html">&lt;p&gt;A key technical challenge for improved performance of the polymer electrolyte fuel cells used in transportation is increasing both activity and stability of the cathode catalyst. The current industry standard for the cathode catalyst is platinum (Pt) nanoparticles on a high-surface area carbon (C). In this study, researchers at the Center on Nanostructuring for Efficient Energy Conversion EFRC at Stanford University developed a high surface area, meso-structured Pt thin film catalyst that exhibits higher specific activity for oxygen reduction than the commercial catalyst.&amp;nbsp;Oxygen reduction to form water is a critical component of the chemical activity in the fuel cell. An accelerated stability test demonstrated that the meso-structured Pt thin film also is significantly more stable than the commercial catalyst. &amp;nbsp;Research reveals that the high turnover frequency and excellent durability is due to the meso-structure. Specifically, the morphology of the structure results in fewer under-coordinated Pt sites than Pt/C nanoparticles, a key difference that improves the specific activity and surface chemistry. The improved catalyst activity and stability resulting from this structure could enable development of high-performance gas diffusion electrodes resistant to corrosion even under the harsh conditions of start-up, shut-down, and/or hydrogen starvation.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{B63CFAA5-2A5D-4CCA-BE2E-7F9EF16C33E6}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-03-b/</link><title>Novel Electrodes for High Performance Batteries</title><description>&lt;img src='/~/media/C8B21ECAE7AC41DDB54ECFA38B7EDB78.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;New nanostructured electrodes have 10 times the charging speed and higher battery power.</description><pubDate>Fri, 10 May 2013 11:21:31 -0400</pubDate><a10:content type="html">&lt;p&gt;Scientists at the University of California, Los Angeles&amp;ndash;based EFRC, Molecularly Engineered Energy Materials, have developed a novel approach to synthesize nanostructured high performance electrodes useful for the next generation lithium ion batteries. By directly coating active nanocrystals onto pre-formed three-dimensional conducting carbon nanotube (CNT) scaffolds, the need for the binders for structural stability at the nanostructured interfaces was eliminated &amp;ndash; an important advance since binders can decrease the overall battery performance. Use of nanometer-sized particles in electrodes drastically reduces the charging times of batteries and supercapacitors because their high surface area offers ample sites for rapid movement of lithium ions, the material that carries the electrical charge. This conformal coating method provides critical features for high-performance electrodes, including effective pathways for electronic transport, high active-material loading, structural robustness and mechanical flexibility due to the excellent intrinsic properties of the CNT scaffold and the high surface area and shortened lithium-diffusion length of the nanocrystals. Electrodes based on titanium dioxide nanocrystals charged to 80% of full capacity in 5 minutes and showed negligible energy loss after a few hundred cycles.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{6968F56D-89D8-4BAF-A693-DB49B02A7299}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-03-c/</link><title>Lessons from Fukushima</title><description>&lt;img src='/~/media/75A69C29A3F547008DE5E36A43B2E1BE.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Experts look at past nuclear accidents and potential scenarios to identify gaps in understanding nuclear fuel behavior.</description><pubDate>Fri, 10 May 2013 16:24:16 -0400</pubDate><a10:content type="html">&lt;p&gt;When the editors of Science wanted to highlight to their worldwide audience the gaps in our current understanding of nuclear fuel, recently brought to the fore by the accident at Japan&amp;rsquo;s Fukushima reactors following the earthquake and resulting tsunami, they turned to three members of the Materials Science of Actinides EFRC (representing Notre Dame, University of Michigan, and University of California-Davis) to provide that expertise.&amp;nbsp;The primary issue these experts point out is that the materials science and chemistry interactions of fuels in an accident scenario (heating, introduction of seawater, etc.) are very complex and not well known.&amp;nbsp;During the Fukushima shutdown and subsequent flooding, this lack of scientific understanding resulted in a number of uncertainties in emergency response decisions.&amp;nbsp;Unknown factors included the corrosion of the fuel, the chemical complexes formed, the rate of gas generation, and other degradation processes.&amp;nbsp;One problem is that existing studies cannot be extrapolated to the conditions of a core-melt incident. Studies of simulated core-melt events and actual damaged fuel are needed to understand the complicated reactions involving radionuclides and the role of nano-scale actinide materials in promoting the breakdown of fuels. An understanding of the factors that determine the release of radionuclides from damaged fuel elements is central to minimizing impacts on the environment and human health.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{C6F56625-C338-4900-9454-C5CF34C50A47}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-03-a/</link><title>Cutting the Cost for Commercial Gas Purification – Theory Leads the Way for a Materials Solution</title><description>&lt;img src='/~/media/bes/images/highlights/2012/03/cgs-smit-hydrocarbon-separation-thumb.jpg' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Novel material for purifying gases could significantly lower industrial energy costs.</description><pubDate>Mon, 18 Mar 2013 10:16:58 -0400</pubDate><a10:content type="html">
		&lt;p&gt;Scientists at the University of California, Berkeley–based EFRC, the Center for Gas Separation Relevant to Clean Energy Technologies, have experimentally confirmed the theoretical predictions that a novel metal-organic framework (MOF) material could purify several industrially important gases at nearly ambient conditions. MOFs are crystalline compounds consisting of metal clusters attached to organic molecules to form porous structures. Neutron diffraction of the MOF reveals a large surface area and exposed iron cation sites, which can preferentially adsorb unsaturated hydrocarbon molecules. It exhibits excellent performance for the purification of hydrocarbon gases, such as methane, ethylene, and propylene, useful for fuels and plastics, from gas mixtures at conditions much milder than those currently used for the separation of these gases. This patented discovery could result in cost savings for the oil and chemical industries and lower their environmental impacts by replacing existing large-scale energy-intensive gas separation processes. Current production involves cracking longer chain hydrocarbons at high temperatures (up to 500-600 °C) and separating the resulting products at high pressures and cryogenic temperatures (-100 °C). This material may also be capable of purifying natural gas streams containing a number of impurity gases.&lt;/p&gt;
</a10:content></item><item><guid isPermaLink="false">{C96ABF32-A742-4480-AA6E-DBD9DACF8858}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-02-a/</link><title>“One Pot” Recipe for Biofuels</title><description>&lt;img src='/~/media/282736F172E64753A6B6F6F65320E625.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;“One pot” catalyst converts up to 20% of dry biomass to a critical chemical used in biofuel production.</description><pubDate>Fri, 10 May 2013 11:21:28 -0400</pubDate><a10:content type="html">&lt;p&gt;Furfural is a useful chemical that can be obtained from plant biomass. In addition to being a component in synthesis of industrial and household products, furfural has increasing potential as a non-petroleum-based, renewable building block for liquid transportation fuels.&amp;nbsp;Strong acids have typically been used to make furfural by converting sugars such as xylose from hemicellulosic polysaccharides, a major component of plant biomass. However, this can result in breakdown of furfural to unwanted products, reducing overall yield. Research in the C3Bio Energy Frontier Research Center (EFRC) demonstrated that use of maleic acid, a weak acid, provides a more efficient method to obtain furfural.&amp;nbsp;The researchers at Purdue University used kinetic studies to determine optimal temperatures and times for the two-step process using maleic acid first to extract xylose from untreated biomass, either maize, switchgrass, pine or poplar, and then to convert the xylose to furfural. Because maleic acid can accomplish both conversion steps, this &amp;ldquo;one-pot&amp;rdquo; strategy produced furfural at higher yields and resulted in less degradation of both xylose and furfural than use of strong acids.&amp;nbsp;Further, this process may be less expensive and more environmentally friendly than other available technologies.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{284C89CB-6EE5-4F98-8AFF-C931A52408E3}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-02-b/</link><title>Pumping up the Yield of Biofuels</title><description>&lt;img src='/~/media/4AE2943B0D1A40E29166D9D2EB53D1C5.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;A scalable catalytic process improves the yield of biofuels by 40%.</description><pubDate>Fri, 10 May 2013 11:21:29 -0400</pubDate><a10:content type="html">&lt;p&gt;Catalytic fast pyrolysis (CFP) is a promising technology for the production of renewable aromatic compounds, including commercially important chemicals such as benzene, toluene, and xylenes, directly from solid biomass.&amp;nbsp;In this single-step process, biomass, including wood, agricultural wastes and fast-growing energy crops, is fed into a fluidized-bed reactor where the biomass thermally decomposes to form pyrolysis vapors, the gases released from the processing. These pyrolysis vapors then enter the zeolite catalysts, which are also in the fluidized-bed reactor, and are converted into the desired aromatic compounds and olefins, types of hydrocarbon, along with carbon monoxide, carbon dioxide, water, and coke, a high-carbon fuel.&amp;nbsp;The spent catalyst and coke are sent to a regenerator where they are burned. The advantages of the new process are: 1) all the desired chemistry occurs in one single reactor, 2) the process uses an inexpensive silica&amp;ndash;alumina catalyst, and 3) aromatics and olefins are produced that fit easily into existing infrastructures.&amp;nbsp; Research was performed at the University of Massachusetts as a part of the Catalysis Center for Energy Innovation EFRC, and has been licensed to Annelotech.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{22A68D8F-2D69-47B5-8B56-8D5155A0AF70}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-02-c/</link><title>Tether No More: A Revised Model for Plant Cell Walls</title><description>&lt;img src='/~/media/805EA3C9556C490FA8D33F9F4677B432.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Biomechanical studies challenge current depictions of plant primary cell wall architecture.</description><pubDate>Fri, 10 May 2013 11:21:29 -0400</pubDate><a10:content type="html">&lt;p&gt;Growing plant cells are surrounded by a primary cell wall consisting predominantly of polymers of sugars (cellulose, hemicellulose, and pectin).&amp;nbsp;Xyloglucan, typically referred to as hemicellulose, is widely believed to act as a tether between cellulose fibers, limiting cell enlargement and regulating cell wall mechanical properties. To test this model, Center for Lignocellulose Structure and Formation EFRC researchers at Pennsylvania State University assessed the biomechanical properties of the cell wall.&amp;nbsp;Experiments examined the ability of primary cell walls to undergo creep &amp;mdash; irreversible increases in the length of the walls due to loosening of the connections between cell wall components &amp;mdash; in response to three types of enzymes, termed endoglucanases, that causes breakdown(hydrolysis) of either xyloglucan, cellulose, or both. &amp;nbsp;The xyloglucan-specific and cellulose-specific endoglucanases, either by themselves or in combination, failed to induce creep; endoglucanases that hydrolyze both xyloglucan and cellulose induced a high creep rate and were able to break down the cell wall. These results suggest xyloglucan does not act as a load-bearing tether between cellulose microfibrils. Rather, a minor xyloglucan component may be located in the limited regions of tight contact between cellulose fibers, playing an important role in wall mechanics.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{919B9B1C-E837-4B31-99B7-7C46FEC0B565}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-02-d/</link><title>Hydrogen Production Forwards and Backwards</title><description>&lt;img src='/~/media/A8B670E8FCE14632BBB8A00367828038.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;A single reversible catalyst enables energy to be both stored and released on demand.</description><pubDate>Fri, 10 May 2013 11:21:29 -0400</pubDate><a10:content type="html">&lt;p&gt;Alternative energy sources like wind and solar produce intermittent power that must be stored for later use when the wind stops blowing or the sun sets.&amp;nbsp;One storage mechanism is to transform electrical energy from solar and wind into chemical energy like hydrogen, but this can be complex and costly.&amp;nbsp;To produce hydrogen efficiently, Center for Molecular Electrocatalysis (CME) researchers are designing a hydrogen splitting catalyst based on the hydrogenase enzyme found in nature. Hydrogenase cleaves two linked hydrogen atoms (dihydrogen) into electrical energy, and it can reverse the reaction to form dihydrogen.&amp;nbsp;This enzyme also has features CME researchers want &amp;ndash; a single catalyst that works at ambient temperature and pressure, and an active site that uses abundant metals such as iron or nickel.&amp;nbsp;To build the synthetic catalyst, molecular strands called ligands were attached to a nickel active site.&amp;nbsp;Using theory and experiments, researchers varied size, shape, and electronic properties of the ligands to &amp;ldquo;tune&amp;rdquo; catalytic activity.&amp;nbsp;One nickel complex displayed reversible dihydrogen production and cleavage with high efficiency &amp;ndash; the first example of a molecular complex to catalyze these reversible reactions.&amp;nbsp;While the catalyst is slow, it wastes little energy and marks an important first step towards improving capabilities for energy storage.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{2DD28828-1A73-48B0-9DDB-99D24FD1EB67}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-02-e/</link><title>Brains, Knees, . . . and now Batteries</title><description>&lt;img src='/~/media/D98C123D059A443294201C6B5047C261.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Magnetic resonance imaging (MRI) method non-destructively images the chemical and structural changes in a lithium ion battery.</description><pubDate>Fri, 10 May 2013 11:21:30 -0400</pubDate><a10:content type="html">&lt;p&gt;The most attractive, highest energy density anode material for a lithium (Li) ion battery is lithium metal itself.&amp;nbsp;However, Li metal battery commercialization has been hampered by safety concerns about the formation of extended Li metal microstructures that can create a short circuit between electrodes.&amp;nbsp;Two key questions emerge: (1) In what form is the Li metal deposited - bulk, porous (aka mossy), or dendritic? and (2) How can Li dendrites be prevented?&amp;nbsp;As part of the Northeastern Center for Chemical Energy Storage EFRC, a research team from New York University, Stony Brook University, and Cambridge University has developed a suite of magnetic resonance imaging (MRI) techniques for characterizing deposited lithium inside a working battery cell. Because the radio frequency energy used in MRI has a limited penetration into bulk Li metal but much greater penetration into more porous microstructures, the amount of Li metal microstructure formed during cycling can be quantified by measuring the increase in signal strength.&amp;nbsp;In 2-D and 3-D&lt;sup&gt;7&lt;/sup&gt;LI MRI techniques, bulk magnetic susceptibility has different signals for the dendrites and the Li metal moss that grow on the Li metal anode, revealing both the location and nature of the microstructural lithium under the operating conditions of the battery.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{0012DAE9-742F-4195-A7D5-B1DA6AA0A7B2}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-02-f/</link><title>Being Uncoordinated Can Improve Thermoelectric Performance</title><description>&lt;img src='/~/media/51F989FDF7484AC98CFADE863CA10563.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Antimony atoms with uncoordinated electrons block flow of heat in thermoelectric materials.</description><pubDate>Fri, 10 May 2013 11:21:30 -0400</pubDate><a10:content type="html">&lt;p&gt;The primary challenge in designing thermoelectric materials with efficient heat-to-electricity conversion is maintaining good transmission of electrons through an atomic structure designed to have low thermal conductivity.&amp;nbsp;Adding nanosized defects and impurities to the material can block the lattice vibrations responsible for heat transport, but this approach can also degrade electrical transport and may reduce thermally stability.&amp;nbsp;In the search for new thermoelectric materials which have intrinsically low thermal conductivity, researchers in the Revolutionary Materials for Solid State Energy Conversion EFRC discovered a direct link between the structure and bonding of compounds containing antimony atoms and the lattice thermal conductivity.&amp;nbsp; Antimony (Sb) ions can assume either a pentavalent (+5) state with coordination to four nearest neighbor atoms via bonding or a trivalent (+3) state with coordination to only three nearest neighbor atoms and the retention of two &amp;ldquo;lone-pair&amp;rdquo; electrons in one of the four Sb coordination sites.&amp;nbsp;Theoretical lattice dynamics computations determined that strong anharmonicity is induced in the lattice vibrational spectrum of Sb compounds with &amp;ldquo;lone-pair&amp;rdquo; electrons.&amp;nbsp;Because lattice anharmonicity drives thermal resistance in solids, these compounds and others like them that contain loan pairs should exhibit intrinsically low thermal conductivity that is &amp;ldquo;built into&amp;rdquo; the crystal structure.&amp;nbsp;This was confirmed experimentally in copper antimony selenide semiconductors.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{B2110407-341F-4913-BBBE-A5D2F6DBCEC9}</guid><link>http://science.energy.gov/bes/highlights/2012/bes-2012-01-b/</link><title>Metal Oxide Nanosheets: Graphene's Inorganic Cousin</title><description>&lt;img src='/~/media/bes/images/highlights/2012/01/emc2-abruna-metal-oxide-nanosheets-thumb.jpg' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;New, scalable manufacturing technique grows metal oxide nanosheets with astronomical aspect-ratios, opening the door to intriguing material properties.</description><pubDate>Mon, 18 Mar 2013 10:16:58 -0400</pubDate><a10:content type="html">
		&lt;p&gt;Scientists at the Energy Materials Center at Cornell (emc2), a DOE Energy Frontier Research Center, have developed a novel synthesis for millimeter-length nanosheets of the complex metal oxide, sodium cobalt oxide (Na&lt;sub&gt;x&lt;/sub&gt;CoO&lt;sub&gt;2&lt;/sub&gt;). The scalable method is capable of producing tens of thousands of nanosheets with dimensions large enough to use in devices. Similar to the unusual 2-D form of carbon known as graphene, nanosheets of metal oxide crystals present exciting opportunities to study and exploit their novel electronic, ferromagnetic, magneto-optical, electrochemical, catalytic, and photoresponsive properties, while being stable at high temperatures and in severe chemical environments. Researchers   used an electric field to move, or demix, the sodium (Na) cations in a pellet   of mixed metal oxides.  The nanosheets formed   in the resulting Na-enriched regions of the pellet have thicknesses in the   tens of nanometers while their lateral lengths are millimeters, resulting in a   very dramatic, anisotropic aspect ratio (10&lt;sup&gt;–5&lt;/sup&gt;: 1 : 1). The stacks of nanosheets are readily peeled-off to make free-standing, individual sheets, reaching up to 350 microns in length with thicknesses of only 20–100 nm. Although they are ceramics, these nanosheet materials display ductility during bending and the individual nanosheets are transparent to visible light.&lt;/p&gt;
</a10:content></item><item><guid isPermaLink="false">{C24B58DB-6E77-46D5-863D-9B9F4E5448BB}</guid><link>http://science.energy.gov/bes/highlights/2011/bes-2011-12-a/</link><title>A New Tool to Probe the Inner Workings of Rechargeable Batteries</title><description>&lt;img src='/~/media/bes/images/highlights/2011/12/cees-thackeray-sei-layer-thumb.jpg' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;A new spectroscopic “fingerprinting” technique has been developed at a DOE user facility to identify chemical degradation products deep inside a working rechargeable battery.</description><pubDate>Mon, 18 Mar 2013 10:17:00 -0400</pubDate><a10:content type="html">
		&lt;p&gt;Understanding what happens inside of rechargeable batteries is critical to making them safer and last longer. For commercially important lithium-based batteries, a new tool has been developed that uses high resolution lithium and oxygen spectroscopy to study the degradation products   formed in a working battery. Inelastic x-ray scattering (IXS) measures and analyzes the energy lost by x-rays when they are scattered by light elements such as lithium; the resulting spectrum is very sensitive to the bonding and chemical structure of the atoms in the material being analyzed. Unlike traditional spectroscopic probes, IXS uses high energy x-rays that can penetrate deep inside a working battery – assessing the elemental changes at the critical solid-electrolyte interface(SEI) inside the battery. Work at Argonne National Laboratory supported by the Center for Electrical Energy Storage, a DOE Energy Research Frontier Center, is using lithium and oxygen spectra of pure, known compounds to create a catalogue of spectroscopic fingerprints of the possible decomposition productions in lithium-ion batteries. Theoretical calculations agree with the measured spectra of pure   compounds, providing validation that the IXS spectra can be used to probe an unknown mixture of SEI products. Ongoing studies will use the fingerprints to determine the composition of the SEI and to decouple decomposition reactions from actual discharge products for a Li-air battery. This technique is now available to the broader battery research community at Argonne’s Advanced Photon Source.&lt;/p&gt;
</a10:content></item><item><guid isPermaLink="false">{78BE572D-13E7-4977-99C6-36A4F2A19699}</guid><link>http://science.energy.gov/bes/highlights/2011/bes-2011-12-b/</link><title>Fuel Cell Catalysts Caught in the Act of Aging</title><description>&lt;img src='/~/media/bes/images/highlights/2011/12/emc2-abruna-track-nanocatalysts-thumb.jpg' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Researchers have captured the first three-dimensional images of changes in shape, composition, and position of individual catalyst particles during electrochemical cycling.</description><pubDate>Mon, 18 Mar 2013 10:16:59 -0400</pubDate><a10:content type="html">
		&lt;p&gt;Proton exchange membrane  fuel cells (PEMFCs) represent a higher efficiency and environmentally-friendly  alternative to the internal combustion engine used in automobiles, but commercialization  is limited due to the degradation of the cathode catalyst that is critical to fuel cell operation.  Previous work to understand  catalyst degradation mechanisms after electrochemical aging involved  destructive techniques that precluded making repeated observations of the same  particle over time. The Energy Materials Center at Cornell (emc&lt;sup&gt;2&lt;/sup&gt;), an Energy Frontier Research Center (EFRC), designed and performed experiments to use non-destructive 3-D  tomographic methods to track the trajectories and morphological changes of over 300 Pt-Co nanocatalyst  particles on a fuel cell carbon support as they aged during electrochemical  cycling. The EFRC researchers discovered that coarsening was dominated by the movement  and coalescence of the nanocatalyst particles into multicore particles rather  than the result of carbon support degradation or a ripening process (larger  nanoparticles growing at the expense of smaller ones). These results suggest that minimizing  nanocatalyst particle movement, possibly by using functional groups on the carbon support to slow down particle movement, should extend the performance of fuel cells.&lt;/p&gt;
</a10:content></item><item><guid isPermaLink="false">{4312E512-F3C4-440C-9D33-3668A3A6D307}</guid><link>http://science.energy.gov/bes/highlights/2011/bes-2011-12-c/</link><title>Nanocrystal Solar Cells Squeeze Extra Juice Out of Sunlight</title><description>&lt;img src='/~/media/564DE5CBE1104A80A3C6BB936F063CC7.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Laboratory measurements of “carrier multiplication” verified in real solar energy photovoltaic devices made of tiny quantum dots.</description><pubDate>Fri, 10 May 2013 11:13:33 -0400</pubDate><a10:content type="html">&lt;p&gt;Carrier multiplication (CM), also known as multiexciton generation (MEG), is a phenomenon whereby a single photon creates more than one electron-hole pair, which can boost the current in a solar cell. The development of quantum dot CM-enhanced solar cells has been frustrated by inconsistencies in measured CM efficiencies that thwart materials optimization efforts, and poor conductivity in quantum dot films that makes collection of the extra carriers inefficient. Recently, Center for Advanced Solar Photophysics (CASP) research at Los Alamos National Laboratory and the National Renewable Energy Laboratory has made key advances on both fronts. In parallel efforts, CASP spectroscopists established a rigorous and reproducible protocol for evaluating true CM efficiencies of different materials, while CASP synthesis researchers developed an effective methodology for fabricating device-grade highly conductive quantum dot films. These efforts culminated in the first exploratory solar cell to show an appreciable increase in current directly attributable to CM, in complete agreement with the spectroscopically determined efficiencies. This is a seminal achievement in the field of third-generation solar technologies, which seeks high efficiencies in low-cost devices through exploitation of novel physics such as CM.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{FA76C0A6-7CC8-43D2-8446-28ED3F447DF3}</guid><link>http://science.energy.gov/bes/highlights/2011/bes-2011-12-d/</link><title>Peering into the Flame</title><description>&lt;img src='/~/media/7759C2046B074D14BDFDB00567405E75.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;New insights from synchrotron-based studies are helping to assess the potential of new biofuels.</description><pubDate>Fri, 10 May 2013 11:13:34 -0400</pubDate><a10:content type="html">&lt;p&gt;Evaluation of new fuels in engines is hampered by both expense and need for large quantities of the test fuel &amp;mdash; a problem given the limited availability for many potential biofuels. Predictive computer modeling based on quantum mechanics and chemistry promises to reduce the number of experiments needed for evaluation. To validate the fidelity of combustion chemistry models, researchers at the CEFRC conducted rigorous experimental tests of the computer predictions for combustion of butanol, an alternative fuel nearing commercialization.&amp;nbsp;Using the Advanced Light Source, a synchrotron that generates bright beams of x-rays capable of revealing atomic and electronic structure of matter, the scientists were able to quantify the chemical species in butanol flames, including species not observable using ordinary techniques.&amp;nbsp;While showing that the model predictions resemble the experimental data and are generally accurate, the research identified areas for improvement. Overall, the results suggest the computer modeling approach currently being developed will accelerate the evaluation of proposed fuels while reducing cost and fuel use.&lt;/p&gt;</a10:content></item><item><guid isPermaLink="false">{928E672F-9926-4038-9094-E7913094611B}</guid><link>http://science.energy.gov/bes/highlights/2011/bes-2011-11-a/</link><title>Holes Are a Positive Thing: Designing Conductors for Solar Photovoltaics</title><description>&lt;img src='/~/media/23AF46BE7E3F4EFFAFAB4B22463F0C11.ashx' align='left' style='height:75px;width:135px;margin-right:10px;margin-bottom:10px;'/&gt;Predicted by theory, and confirmed by experiments, novel materials are being discovered to improve photovoltaic efficiency.</description><pubDate>Fri, 10 May 2013 11:13:33 -0400</pubDate><a10:content type="html">&lt;p&gt;In the quest for more efficient photovoltaic technologies, scientists at the Center for Inverse Design (CID) EFRC are using an unconventional approach to discover new materials for improved transparent semiconductors for solar energy. It is relatively easy to improve positive-charge (p-type) conductivity in small-gap semiconductors, such as silicon. Small quantities of atoms, called dopants, that pull electrons from the semiconductor are added, resulting in a concentration of positively charged &amp;ldquo;holes&amp;rdquo;&amp;mdash;the charge carriers for p-type conductors. However, it is difficult to combine p-type conductivity and optical transparency in the wide gap materials that are desired for PV applications; wide gap materials could enable more efficient devices due to their high temperature and voltage performance. To solve this challenge, CID uses theory to establish design rules for desired properties and to screen candidate oxides, and then synthesizes and experimentally characterizes those with the best predicted properties. Theory predicted that spinel cobalt zinc oxide (Co&lt;sub&gt;2&lt;/sub&gt;ZnO&lt;sub&gt;4&lt;/sub&gt;) with additions of magnesium or nickel would increase hole concentration and thus conductivity. Experiments demonstrated a 20-fold increase in hole density with magnesium dopants and a 100-fold increase with nickel dopants. These easily grown oxides may enhance solar panel efficiencies over currently available transparent conducting oxides.&lt;/p&gt;</a10:content></item></channel></rss>