National User Facility Research Articles

Wakefield generation in hydrogen and lithium plasmas at FACET-II: Diagnostics and first beam-plasma interaction results

Plasma wakefield acceleration provides ultrahigh acceleration gradients of tens of GeV/m, providing a novel path toward efficient, compact, TeV-scale linear colliders, and high brightness free electron lasers. Critical to the success of these applications is demonstrating simultaneously high gradient acceleration, high energy transfer efficiency, and preservation of emittance, charge, and energy spread. Experiments at the FACET-II National User Facility at SLAC National Accelerator Laboratory aim to achieve all of these milestones in a single-stage plasma wakefield accelerator, providing a 10 GeV energy gain in a <1 m plasma with high energy transfer efficiency. Such a demonstration depends critically on diagnostics able to measure emittance with mm mrad accuracy, energy spectra to determine both percent level energy spread, and broadband energy gain and loss, incoming longitudinal phase space, and matching dynamics. This paper discusses the experimental setup at FACET-II, including the incoming beam parameters from the FACET-II linac, plasma sources, and diagnostics developed to meet this challenge. Initial progress on the generation of beam ionized wakes in meter-scale hydrogen gas is discussed as well as commissioning of the plasma sources and diagnostics. Published by the American Physical Society 2024

DIII-D's role as a national user facility in enabling the commercialization of fusion energy

The path to fusion in the United States requires partnership between public and private sector. While the private sector provides the vigor to take some of the major steps necessary, there is a depth of expertise and capability in the public sector that is vital to resolving feasible approaches. As an open national user facility, DIII-D provides a crucial testbed to develop the required new technologies and approaches in relevant conditions. It has unparalleled potential to meet this challenge, thanks to its extreme flexibility and world leading diagnostics. This provides a basis to rapidly develop solutions that project to future reactors with confidence. The program has thus been redeveloped to enable public and private sector engagement and testing of new concepts. A new technology program has been launched to resolve plasma interacting technologies. With modest heating upgrades, the facility can confront the crucial “Integrated Tokamak Exhaust and Performance” gap, to resolve core, exhaust and technology solutions together. The device is also being redeveloped as a training facility, with dedicated student run time, a mentorship program, and open access to all opportunity roles, part of wider efforts to diversify and open pathways through inclusion, access, and equity. This exciting agenda is enabling scientists and technology researchers to pioneer the solutions needed for a Fusion Pilot Plant (FPP) and ITER this decade. As a national user facility, DIII D has singular potential to provide the tools, teams, and insight necessary, to do its part in moving the United States rapidly toward the commercialization of fusion energy.

User capabilities at the GM/CA@APS Structural Biology Facility at the Advanced Photon Source

The General Medical Sciences and Cancer Institutes’ structural biology facility at the APS (GM/CA@APS) operates a National User Facility for crystallographic structure determination of biological macromolecules, with an emphasis on challenging, high-impact projects. The facility includes canted-undulator beamlines, 23ID-B and 23ID-D, that provide stable, intense X-ray beams of user-selectable size down to 5-micron, an intuitive user interface for experiment control, and an automated data processing pipeline.

FACET-II facility for advanced accelerator experimental tests

The National User Facility for Advanced Accelerator Experimental Tests II (FACET-II) at SLAC National Accelerator Laboratory expands upon the experiments conducted at FACET. Its purpose is to build upon the decades-long experience developed conducting accelerator R at SLAC in the areas of advanced acceleration and coherent radiation techniques with high-energy electron and positron beams. This paper summarizes the motivations for the design and resulting capabilities of the FACET-II facility.

Advances of the FRIB project

The Facility for Rare Isotope Beams (FRIB) Project has entered the phase of beam commissioning starting from the room-temperature front end and the superconducting linac segment of first 15 cryomodules. With the newly commissioned helium refrigeration system supplying 4.5[Formula: see text]K liquid helium to the quarter-wave resonators and solenoids, the FRIB accelerator team achieved the sectional key performance parameters as designed ahead of schedule accelerating heavy ion beams above 20[Formula: see text]MeV/u energy. Thus, FRIB accelerator becomes world’s highest-energy heavy ion linear accelerator. We also validated machine protection and personnel protection systems that will be crucial to the next phase of commissioning. FRIB is on track towards a national user facility at the power frontier with a beam power two orders of magnitude higher than operating heavy-ion facilities. This paper summarizes the status of accelerator design, technology development, construction, commissioning as well as path to operations and upgrades.

An upgraded and integrated large-volume high-pressure facility at the GeoSoilEnviroCARS bending magnet beamline of the Advanced Photon Source

GeoSoilEnviroCARS (GSECARS) is an earth-science-driven X-ray synchrotron facility at the Advanced Photon Source of the Argonne National Laboratory. As a national user facility, we provide users with access to the high-brilliance hard X-rays from this third-generation synchrotron light source. The multi-anvil, large-volume high-pressure facility at the bending magnet beamline (13-BM-D) runs a unique setup permitting an unusually wide range of high-pressure and high-temperature experiments combined with X-rays and other in-situ probing techniques. It has been a great asset for the high-pressure earth science community since its inception in 1997. A series of upgrades and updates occurred in the 2010s. Here we provide a detailed description of the current large-volume press (LVP) setup at 13-BM-D, including hardware, software, and all experimental capabilities. Examples of scientific studies that were performed at GSECARS utilizing the new LVP system are also reported.

Boehmite and Gibbsite Nanoplates for the Synthesis of Advanced Alumina Products.

Boehmite (γ-AlOOH) and gibbsite (α-Al-(OH)3) are important archetype (oxy)hydroxides of aluminum in nature that also play diverse roles across a plethora of industrial applications. Developing the ability to understand and predict the properties and characteristics of these materials, on the basis of their natural growth or synthesis pathways, is an important fundamental science enterprise with wide-ranging impacts. The present study describes bulk and surface characteristics of these novel materials in comprehensive detail, using a collectively sophisticated set of experimental capabilities, including a range of conventional laboratory solids analyses and national user facility analyses such as synchrotron X-ray absorption and scattering spectroscopies as well as small-angle neutron scattering. Their thermal stability is investigated using in situ temperature-dependent Raman spectroscopy. These pure and effectively defect-free materials are ideal for synthesis of advanced alumina products.

The ATLAS multi-user upgrade and potential applications

With the recent integration of the CARIBU-EBIS charge breeder into the ATLAS accelerator system to provide for more pure and efficient charge breeding of radioactive beams, a multi-user upgrade of the ATLAS facility is being proposed to serve multiple users simultaneously. ATLAS was the first superconducting ion linac in the world and is the US DOE low-energy Nuclear Physics National User Facility. The proposed upgrade will take advantage of the continuous-wave nature of ATLAS and the pulsed nature of the EBIS charge breeder in order to simultaneously accelerate two beams with very close mass-to-charge ratios; one stable from the existing ECR ion source and one radioactive from the newly commissioned EBIS charge breeder. In addition to enhancing the nuclear physics program, beam extraction at different points along the linac will open up the opportunity for other potential applications; for instance, material irradiation studies at ∼1 MeV/u, isotope production and radiobiological studies at ∼6 MeV/u and at the full ATLAS energy of ∼15 MeV/u. The concept and proposed implementation of the ATLAS multi-user upgrade will be discussed. Future plans to enhance the flexibility of this upgrade will be presented.

Exploring the Dichotomy of Ionomer and Membrane Properties

Ion-conductive polymers are critical components of polymer-electrolyte fuel cells, where they their primary role is to facilitate selective proton transport as the polymer electrolyte membrane (PEM). Another important role they play is in the catalyst-layer of the PEFC, where they extend their proton-transport functionality to the catalytic sites, where they are found as nanometer-thick electrolyte “thin film” covering carbon and platinum nanoparticles. Although ionomers are responsible for efficient proton conductivity as both PEM and CL electrolyte, their functionality differs. While a PEM ionomer is expected to inhibit gas crossover, a CL ionomer should be able to transport these gases, in particular oxygen, to the catalytic sites as well. Any limitation to the oxygen transport through the ionomer film to the Pt sites results in mass-transport losses with dramatic decrease in cell performance. Thus, improving fuel-cell performance requires ionomers tuned specifically for each component, i.e. PEM and CL, with distinctly different gas transport functionalities. Such a modification presents a challenge for the same ionomer, whose transport properties are governed by its physicochemical properties and morphology. Thus, for the desired next-generation fuel cells, a new paradigm is needed for the design and optimization of ionomers, with alternative chemistries beyond Nafion, the prototypical fuel-cell ionomer. In PEFCs, Nafion, a perfluorosulfonic acid (PFSA) ionomer, is the most widely used material and research on other PFSAs, in particular with varying side-chain chemistries and equivalent weights (EWs), have been relatively scarce. Thus, by exploring the effect of chemistry and EW on ionomer’s structure/functionality, one could work toward identifying key factors controlling transport properties, and how they can be tuned for a bulk membrane (i.e., PEM) and a catalyst thin film. This talk presents a comparison of various side-chain chemistry effects on structure/function relationships of PFSA ionomers from bulk membranes to thin films confined to nanometer thickness. The interplay between the side-chain chemistry and film thickness will be examined for several PFSAs, including multi-acid chain (MASC) ionomers to elucidate the factors controlling their swelling behavior and various transport properties. In addition, these properties will be correlated to the morphological features studied by small- and wide-angle X-ray scattering (SAXS/WAXS) for membranes and grazing-incidence SAXS (GISAXS) for thin films. It will be shown how an ionomer's nanostructure and transport properties deviate from the bulk when it is confined to nm-thick films and how these deviations are impacted by the side-chain. The results will be used to highlight design guidelines for ionomers as fuel-cell membranes and catalyst films, and then correlated with the fuel-cell performance to provide insight into optimization of their functionalities for PEFCs and other energy storage and conversion technologies. Acknowledgement We thank Mike Yandrasits and Andrew Haug of 3M for providing the ionomers and helpful discussions. This work was funded under the Fuel Cell Performance and Durability Consortium (FC-PAD), by the Fuel Cell Technologies Office (FCTO), Office of Energy Efficiency and Renewable Energy (EERE), of the U.S. Department of Energy under contract number DE-AC02-05CH11231. X-ray experiments were performed in the beamline 7.3.3 at Advanced Light Source (ALS), Lawrence Berkeley National Laboratory, which is a national user facility funded by the Department of Energy, Office of Basic Energy Sciences, under contract number DE-AC02-05CH11231.

On-the-Fly Data Assessment for High-Throughput X-ray Diffraction Measurements.

Investment in brighter sources and larger and faster detectors has accelerated the speed of data acquisition at national user facilities. The accelerated data acquisition offers many opportunities for the discovery of new materials, but it also presents a daunting challenge. The rate of data acquisition far exceeds the current speed of data quality assessment, resulting in less than optimal data and data coverage, which in extreme cases forces recollection of data. Herein, we show how this challenge can be addressed through the development of an approach that makes routine data assessment automatic and instantaneous. By extracting and visualizing customized attributes in real time, data quality and coverage, as well as other scientifically relevant information contained in large data sets, is highlighted. Deployment of such an approach not only improves the quality of data but also helps optimize the usage of expensive characterization resources by prioritizing measurements of the highest scientific impact. We anticipate our approach will become a starting point for a sophisticated decision-tree that optimizes data quality and maximizes scientific content in real time through automation. With these efforts to integrate more automation in data collection and analysis, we can truly take advantage of the accelerating speed of data acquisition.

(Invited) Development of Dual-Salts/Carbonate-Solvents Electrolytes for Fast Charging and Stable Cycling Lithium Metal Batteries

Rechargeable lithium (Li) metal batteries have received increasing attentions in recent years because of their high theoretical energy densities from the contribution of Li metal anode that has an ultrahigh theoretical specific capacity (3860 mAh g-1), the lowest redox potential (-3.040 V vs. the standard hydrogen electrode) and a low gravimetric density (0.534 g cm-3). However, significant challenges including Li dendrite growth and low Coulombic efficiency still impede the successful deployment of rechargeable Li metal batteries. A lot of efforts have been made in the past 45 years to address these problems, including the application of polymer electrolytes, solid-state electrolytes, ionic liquids, highly concentrated liquid electrolytes, additives, protecting layers, interlayers between Li and separator, nanoscale design, selective deposition, Li-reduced graphene oxide composites, and so on. Although some progresses have been achieved the challenges still remain. It has been reported that ether-based electrolytes are relatively stable with Li metal anode and can allow Li metal anodes to be cycled at reasonably high charging current densities, but these electrolytes are not stable at voltages above 4 V vs. Li/Li+. The conventional Li-ion battery electrolytes based on LiPF6/carbonate-solvents are stable at least up to 4.3 V but they suffer from the low Coulombic efficiency and poor charging current densities due to the reactivity of Li metal with LiPF6 salt and carbonate solvents. In the talk, we present the development of electrolytes based on LiTFSI-LiBOB dual-salt in carbonate solvent mixtures for rechargeable Li metal batteries with conventional Li-ion battery cathodes. It has been found that the dual-salt electrolytes greatly enhance the performances of Li metal batteries in terms of long-term cycling stability and fast charging capability over the conventional LiPF6/carbonate electrolytes. The dual-salt electrolytes also protect Li metal anodes by suppressing the corrosions of Li metal caused by the reactions of Li metal and electrolytes. Certain additives at a small amount level can even further significantly protect the Li metal anode and improve the battery performances. The possible mechanisms have been proposed based on the comprehensive characterizations. The details of the results will be reported at the meeting. Acknowledgements The research has been supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the U.S. Department of Energy (DOE) through the Advanced Battery Materials Research (BMR) Program and the Battery500 Consortium. The microscopy and spectroscopy measurements were performed at the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory.

SRF acceleration for heavy ions: ATLAS decadal operation and evolution

This review paper presents the history and status of superconducting RF at the Argonne Tandem Linac Accelerator System (ATLAS) which is a Department of Energy (DOE) National User Facility for research in nuclear physics with accelerated stable and radioactive ion beams.

(Invited) CsPF6 and Propylene Carbonate in Conventional LiPF6/Carbonate Electrolytes for Enhanced Lithium-Ion Battery Performances in Wide Temperature Range

Lithium-ion batteries (LIBs) have achieved great successes in portable electronic devices and have now started to enter the large-scale energy storage applications in transportations (such as pure electric vehicles and plug-in hybrid electric vehicles) and smart grid. Graphite is widely used as the anode material in the state-of-the-art LIBs. However, the graphite anode is usually only compatible with an ethylene carbonate (EC)-based electrolyte. In a propylene carbonate (PC)-containing electrolyte, which is advantageous over the EC-based counterpart due to its wider temperature range and lower cost, the graphite anode experiences significant exfoliation problem by the PC intercalation during the Li+ intercalation at charging steps. Thus a PC-containing electrolyte cannot be used in LIBs with graphite anode unless some solid electrolyte interphase (SEI) film-formation additives are included in the electrolytes. Such SEI formation additives normally contain unsaturated bonds or are unstable cyclic compounds, e.g. vinylene carbonate (VC), fluoroethylene carbonate (FEC), and lithium bis(oxalato)borate (LiBOB). They play an important role in the protection of the graphite structure from destruction by PC intercalation. However, these additives usually result in a thick SEI layer, which greatly reduces rate capability, limits low-temperature performance and hampers cycling stability at elevated temperatures through additional impedance and poor thermal stability.Recently, we have demonstrated that cesium cation (Cs+) as a novel electrolyte additive can direct the formation of a uniform, ultrathin and compact SEI layer on graphite electrode surface in EC-PC-containing electrolytes.[1] This SEI can not only significantly improve the compatibility between graphite anode and PC-containing electrolyte, but also lead to superior rate capability, enhanced low-temperature discharge performance, and excellent cycling stability at elevated temperatures.We also foundthat PC content in the electrolytes has great effect on the performances of graphite anode in half cells and full cells, and an optimal PC content of 20% by weight in solvent mixtures is identified.[2] The synergistic effects of Cs+ additive and appropriate amount of PC enable the formation of a robust, ultrathin and compact SEI layer on the surface of graphite electrode, which is only permeable for de-solvated Li+ ions and allows fast Li+ transport through it. In the continuation study, we further optimized the electrolyte formulations with CsPF6 additive by adjusting the EC and PC contents in electrolytes and evaluated the performances of graphite||LiNi0.80Co0.15Al0.05O2 full cells in terms of cycling at room temperature and elevated temperature, rate capacity and low-temperature discharge. One optimized electrolyte formulation is found to give about 70% discharge capacity retention at -40°C when compared to the room temperature discharge of the full cells, and simultaneously maintains other excellent performances. It is indicated that the optimal electrolyte consisting of CsPF6 and PC in conventional LiPF6/EC-based electrolyte is of great potential use in the state-of-the-art LIBs. The details of the results will be reported at the meeting. Acknowledgements This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies, the Advanced Battery Materials Research Programs of the U.S. Department of Energy (DOE), and the Laboratory Directed Research and Development (LDRD) Project under the Technology Investment Program at Pacific Northwest National Laboratory (PNNL). The microscopy and spectroscopy measurements were performed at the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the DOE’s Office of Biological and Environmental Research and located at PNNL.

The Effects of Synthesis Conditions on the Performances of Ni-Rich LiNixMnyCozO2 Cathode Materials for Lithium-Ion Batteries

Rechargeable lithium-ion batteries (LIBs) have become the dominant power sources not only for the consumer electronic devices but also for the pure electric vehicles (EVs) and plug-in electric vehicles (PHEVs) because of their high energy density, light weight and long cycle life. The increasing need on minimizing global warming and environmental pollution have accelerated the development of EVs. With the state of the art LIBs used in automobile industry, the driving range of EVs is still far behind those of conventional vehicles using internal combustion engines. Therefore, there is an urgent need to further improve both energy density and power capability of LIBs, to improve the driving range and decrease the recharging time. To meet these requirements, a lot of effort has been made in the search of high energy density electrode materials, especially the cathode materials. Recently, Ni-rich layered cathode materials LiNixMnyCozO2 (x ≥ 0.6) have received great attention as a potential cathode alternative due to their high achievable discharge capacity (200~220 mAh g-1),1 representing a significant improvement in energy density (~780 Wh kg-1) as compared to LiCoO2 (~570 Wh kg-1) and spinel LiMn2O4 (~440 Wh kg-1). Ni-rich cathode materials also show much higher lithium ion diffusion coefficients, signifying a superior power density as compared to other LiNixMnyCozO2 cathodes with lower Ni contents.2 The other advantage of Ni-rich cathode materials is the reduction of production cost owing to the reduced Co content. However, there are still some technical challenges hindering the mass applications of Ni-rich cathode materials, including (i) Li/Ni cation mixing due to the difficulty in maintaining all the Ni in 3+ valence state, (ii) micro strain and micro crack formation due to the significant volume variation during charge/discharge processes, (iii) safety issue because of the aggressive thermal reactions between the delithiated Ni-rich materials and the electrolyte. Much effort has been devoted to improving the electrochemical performance of the Ni-rich cathode materials.3 Representative approaches include lattice doping, surface treatment/modification, tuning the material compositions, and a smart design of core-shell or concentration gradient structures. Other than these useful treatment and design, the synthetic conditions, such as co-precipitation pH value, particle size, lithium content, calcination temperature, calcination atmosphere (O2, air etc.), heating/cooling rates, also play an important role in manipulating the material structural properties and thus influencing the electrochemical performances of prepared Ni-rich cathode materials. Herein, we systematically investigated the effects of calcination temperature on the primary particle size, cation mixing and the electrochemical performances of Ni-rich cathode materials. It is found that higher calcination temperature leads to considerable increase of primary particle size, which is supposed to largely reduce the side reactions between cathode material and the electrolytes. However, the materials prepared at high temperatures exhibited much poorer long-term cycling stability both at room temperature and high temperature of 60oC, in addition to their inferior rate performance. Therefore, the fundamental reasons behind this phenomenon are investigated in detail, which will be presented and discussed during the meeting. Acknowledgements This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies, the Advanced Battery Materials Research Programs of the U.S. Department of Energy (DOE). The microscopy and spectroscopy measurements were performed at the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. References 1) A. Manthiram, J.C. Knight, S-T, Myung, S-M Oh, Y-K Sun, Adv. Energy Mater., 1501010 (2015). 2) Y. Wei, J. Zheng, S. Cui, X. Song, Y. Su, W. Deng, Z. Wu, X. Wang, W. Wang, M. Rao, Y. Lin, C. Wang, K. Amine, F. Pang, J. Am. Chem. Soc., 137, 8364 (2015). 3) W. Liu, P. Oh, X. Liu, M-J Lee, W. Cho, S. Chae, Y. Kim, J. Cho, Angew. Chem. Int. Ed., 54, 4440 (2015).

Stable Operation of Lithium Metal Batteries by the Formation of Transient High Concentration Electrolyte Layer during Fast Discharge

Lithium (Li) metal anode has an ultrahigh theoretical capacity of 3860 mAh/g and the lowest electrochemical potential at -3.040 V vs. standard hydrogen electrode, which makes the rechargeable Li metal batteries as the “holy grail” of energy storage systems.1 However, the development and application of rechargeable Li metal batteries has been hindered in the past decades mainly due to two major problems¾the Li dendrite growth on Li anode during repeated charge/discharge processes and the low Coulombic efficiency. Although several approaches have been reported to suppress Li dendrite growth on Li metal, including forming Li alloys, adding electrolyte additives, using blocking electrolyte membranes, and to improve Coulombic efficiency, the enhancement on Li protection so far is not satisfactory. Recently, highly concentrated ether-based electrolyte has been reported to be more compatible with Li metal anode because high concentration of Li+ ions in these electrolytes facilities the fast Li deposition/stripping even at high current density conditions.2,3 However, ether-based electrolytes may not be suitable for use at charge cutoff voltage higher than ~4.0 V due to their poor stability against oxidation. In this work, we report for the first time the significantly improved performances of Li metal batteries using a LiNi1/3Mn1/3Co1/3O2 (NMC) cathode and a conventional carbonate solvent-based electrolyte by an appropriate cycling protocol to generate a transient, highly concentrated Li+ ion solution layer in the vicinity of Li metal surface. The highly concentrated electrolyte formed in the vicinity of Li anode surface facilitates the formation of an SEI layer with considerably enhanced stability. It is demonstrated that a high capacity retention >80% after 500 cycles can be achieved for the moderately high areal-capacity Li metal batteries at an optimized charging/discharging process. Based on the results of morphology observation and the composition characterization of the cycled Li metal anodes, a more profound understanding of the underlying mechanism behind the improved performances has been obtained. The fundamental findings of this work provide new insights for the further development of high energy density and long cycle life Li metal batteries. Details of the investigations will be reported and discussed in the presentation. Acknowledgements This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies, the Advanced Battery Materials Research Programs of the U.S. Department of Energy (DOE). The microscopy and spectroscopy measurements were performed at the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. References A. Zhanmu, G. Chen, C. Liu, D. Neff, Q. Fang, Z. Yu, W. Xiong, Y. Wang, X. Wang, and B. Z. Jang, Energy Environ. Sci., 5, 5701 (2012). L. Suo, Y.-S. Hu, H. Li, M. Armand, and L. Chen, Nat. Commun., 4, 1481 (2013). J. Qian, W. A. Henderson, W. Xu, P. Bhattacharya, M. Engelhard, O. Borodin, and J.-G. Zhang, Nat. Commun., 6, 6362 (2015).

A Stable Carbon-Free Cathode for Rechargeable Lithium-Oxygen Battery with Long Cycle Performance

Lithium-oxygen (Li-O2) batteries have extremely high theoretical specific capacities and energy densities than Li-ion batteries. It is estimated that a practical Li-O2 battery could provide 3-5 times gravimetric energy density of conventional Li-ion batteries. The cathode active material (oxygen) is not stored in the Li-O2 battery and can be obtained from the environment outside the batteries. However, the cycle performances of these Li-O2 batteries are still limited by the stability of the air electrode and the electrolyte. Carbon-based electrodes are believed to decompose during charge and promote electrolyte decomposition as well. The fabrication of a stable and highly active carbon-free cathode for both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) becomes a great challenge at present for the development of rechargeable Li-O2battery. Recently, some carbon-free cathode materials have been reported, including noble metals,1 oxides,2 and carbides.3 Metal oxides have low conductivities and are mainly utilized at low current densities. Noble metals show outstanding performance but may not be applicable due to the high cost and high density. Carbides can achieve good bi-functional activities for ORR and OER and be with low cost. However, only TiC was reported to achieve high cycle performance as a carbon-free cathode for Li-O2 batteries so far. Here we report the application of a novel material for the carbon-free cathode of Li-O2 batteries. The battery can be stably operated for more than 200 cycles with a stable voltage profile under the capacity-limited condition. With the aid of structure and composition characterizations, the mechanism of discharge and charge process is also investigated. This novel material is very promising for the use as an alternative carbon-free cathode, as well as for studying and exploring the stable electrolyte in rechargeable Li-O2batteries. Acknowledgements This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies, the Advanced Battery Materials Research Programs of the U.S. Department of Energy (DOE). The microscopy and spectroscopy measurements were performed at the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. References Z. Peng, S. A. Freunberger, Y. Chen, P. G. Bruce, A Reversible and Higher-Rate Li-O2 Battery, Science., 337, 563 (2012). M. M. O. Thotiyl, S. A. Freunberger, Z. Peng, Y. Chen, Z. Liu, P. G. Bruce, A stable cathode for the aprotic Li-O2 battery, Nature Materials, 12, 1050 (2013). F. Li, D.M. Tang, Y. Chen, D. Golberg, H. Kitaura, T. Zhang, A. Yamada, H. Zhou, Ru/ITO: A Carbon-Free Cathode for Nonaqueous Li-O2 Battery, Nano Lett., 13, 4702 (2013).

Seeking to bridge Europe’s impending neutron gap

Europe’s primacy in neutron scattering depends on maintaining a network of local and international facilities.

The upgraded Large Plasma Device, a machine for studying frontier basic plasma physics.

In 1991 a manuscript describing an instrument for studying magnetized plasmas was published in this journal. The Large Plasma Device (LAPD) was upgraded in 2001 and has become a national user facility for the study of basic plasma physics. The upgrade as well as diagnostics introduced since then has significantly changed the capabilities of the device. All references to the machine still quote the original RSI paper, which at this time is not appropriate. In this work, the properties of the updated LAPD are presented. The strategy of the machine construction, the available diagnostics, the parameters available for experiments, as well as illustrations of several experiments are presented here.

Overview: Development of the National Ignition Facility and the Transition to a User Facility for the Ignition Campaign and High Energy Density Scientific Research

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory has been operational since March 2009 and has been transitioning to a user facility supporting ignition science, high energy density stockpile science, national security applications, and fundamental science. The facility has achieved its design goal of 1.8 MJ and 500 TW of 3ω light on target, and has performed target experiments with 1.9 MJ at peak powers of 410 TW. The National Ignition Campaign (NIC), established by the U.S. National Nuclear Security Administration in 2005, was responsible for transitioning NIF from a construction project to a national user facility. Besides the operation and optimization of the use of the NIF laser, the NIC program was responsible for developing capabilities including target fabrication facilities; cryogenic layering capabilities; over 60 optical, X-ray, and nuclear diagnostic systems; experimental platforms; and a wide range of other NIF facility infrastructure. This paper provides a summary of some of the key experimental results for NIF to date, an overview of the NIF facility capabilities, and the challenges that were met in achieving these capabilities. They are covered in more detail in the papers that follow.

Behind the Stability of Graphite Anode in PC-Containing Electrolytes with a New Additive

Lithium-ion battery (LIB) is one of the most promising power sources for electronic devices and electric vehicles because of their high energy densities and relatively long lifetime. Graphite is widely used as the anode electrode material in the state-of-the-art LIBs. However, a graphite anode is usually only compatible with an ethylene carbonate (EC)-based electrolyte. In a propylene carbonate (PC)-containing electrolyte, which is advantageous over the EC-based counterpart due to its wider temperature range and higher low-temperature conductivity, the graphite anode experiences significant exfoliation problem during the initial lithium intercalation step. Thus a PC-containing electrolyte cannot be used in LIBs with graphite as the anode unless some solid electrolyte interphase (SEI) film-formation additives are included in the electrolytes. Usually these additives are electrochemically reduced predominantly on the graphite anode surface before PC is intercalated and reduced. Such additives normally contain unsaturated bonds or are unstable cyclic compounds, for instance, vinylene carbonate (VC) and fluoroethylene carbonate (FEC). They play an important role in the protection of the graphitic anode structure from destruction by PC reduction. However, these additives also have certain shortcomings. Usually these additives result in a thick SEI layer, which significantly reduces the rate capability and limits low-temperature performance and cycling stability at elevated temperatures through additional impedance and poor thermal stability. Recently, we developed a novel electrolyte additive that can suppress the PC reductive decomposition on the graphite anode without forming a thick and resistant SEI film. As shown in Figure 1, this additive can not only significantly improve the compatibility between graphite anode and PC-containing electrolyte, but also exhibit superior rate capability and excellent cycling stability at elevated temperatures.This new electrolyte additive can be applied to LIBs and other electrochemical systems using PC-containing electrolytes and graphite anodes. In this work, we systematically investigated the mechanism of the SEI formation by this additive and the protection of graphite anode in PC-containing electrolytes. Several techniques, including computational calculations and simulations, 17O nuclear magnetic resonance (NMR), “soft” electrospray ionization mass spectrometry (ESI-MS), time of flight second ion mass spectrometry (ToF-SIMS), etc. have been used to reveal the reasons behind the compatibility and stability of graphite anode in PC-containing electrolytes with this new additive. The details of the results will be reported at the meeting. Acknowledgements This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technology of the U.S. Department of Energy (DOE). The 17O NMR and ToF-SIMS measurements were performed at the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the DOE’s Office of Biological and Environmental Research and located at PNNL. Figure 1