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ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTAqueous Rechargeable Li and Na Ion BatteriesHaegyeom Kim†, Jihyun Hong†, Kyu-Young Park†, Hyungsub Kim†, Sung-Wook Kim§, and Kisuk Kang*†‡View Author Information† Department of Materials Science and Engineering, Research Institute of Advanced Materials (RIAM), Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 151-742, Republic of Korea‡ Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 151-742, Republic of Korea§ Nuclear Fuel Cycle Development Group, Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353, Republic of Korea*Phone: +82-2-880-7088. Fax: +82-2-885-9671. E-mail: [email protected]Cite this: Chem. Rev. 2014, 114, 23, 11788–11827Publication Date (Web):September 11, 2014Publication History Received28 April 2014Published online11 September 2014Published inissue 10 December 2014https://pubs.acs.org/doi/10.1021/cr500232yhttps://doi.org/10.1021/cr500232yreview-articleACS PublicationsCopyright © 2014 American Chemical SocietyRequest reuse permissionsArticle Views42966Altmetric-Citations1203LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Batteries,Electrodes,Electrolytes,Ions,Redox reactions Get e-Alerts
The supercritical CO2 (S-CO2) Brayton cycle has recently been gaining a lot of attention for application to next generation nuclear reactors. The advantages of the S-CO2 cycle are high efficiency in the mild turbine inlet temperature region and a small physical footprint with a simple layout, compact turbomachinery, and heat exchangers. Several heat sources including nuclear, fossil fuel, waste heat, and renewable heat sources such as solar thermal or fuel cells are potential application areas of the S-CO2 cycle. In this paper, the current development progress of the S-CO2 cycle is introduced. Moreover, a quick comparison of various S-CO2 layouts is presented in terms of cycle performance.
The centrality dependence of transverse momentum distributions and yields for pi^+/-, K^+/-, p and p^bar in Au+Au collisions at sqrt(s_NN) = 200 GeV at mid-rapidity are measured by the PHENIX experiment at RHIC. We observe a clear particle mass dependence of the shapes of transverse momentum spectra in central collisions below ~ 2 GeV/c in p_T. Both mean transverse momenta and particle yields per participant pair increase from peripheral to mid-central and saturate at the most central collisions for all particle species. We also measure particle ratios of pi^-/pi^+, K^-/K^+, p^bar/p, K/pi, p/pi and p^bar/pi as a function of p_T and collision centrality. The ratios of equal mass particle yields are independent of p_T and centrality within the experimental uncertainties. In central collisions at intermediate transverse momenta ~ 1.5-4.5 GeV/c, proton and anti-proton yields constitute a significant fraction of the charged hadron production and show a scaling behavior different from that of pions.
The anisotropy parameter (${v}_{2}$), the second harmonic of the azimuthal particle distribution, has been measured with the PHENIX detector in $\mathrm{A}\mathrm{u}+\mathrm{A}\mathrm{u}$ collisions at $\sqrt{{s}_{NN}}=200\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$ for identified and inclusive charged particle production at central rapidities ($|\ensuremath{\eta}|<0.35$) with respect to the reaction plane defined at high rapidities ($|\ensuremath{\eta}|=3--4\text{ }$). We observe that the ${v}_{2}$ of mesons falls below that of (anti)baryons for ${p}_{T}>2\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}/c$, in marked contrast to the predictions of a hydrodynamical model. A quark-coalescence model is also investigated.
Abstract The joint evaluated fission and fusion nuclear data library 3.3 is described. New evaluations for neutron-induced interactions with the major actinides $$^{235}\hbox {U}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow/><mml:mn>235</mml:mn></mml:msup><mml:mtext>U</mml:mtext></mml:mrow></mml:math> , $$^{238}\hbox {U}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow/><mml:mn>238</mml:mn></mml:msup><mml:mtext>U</mml:mtext></mml:mrow></mml:math> and $$^{239}\hbox {Pu}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow/><mml:mn>239</mml:mn></mml:msup><mml:mtext>Pu</mml:mtext></mml:mrow></mml:math> , on $$^{241}\hbox {Am}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow/><mml:mn>241</mml:mn></mml:msup><mml:mtext>Am</mml:mtext></mml:mrow></mml:math> and $$^{23}\hbox {Na}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow/><mml:mn>23</mml:mn></mml:msup><mml:mtext>Na</mml:mtext></mml:mrow></mml:math> , $$^{59}\hbox {Ni}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow/><mml:mn>59</mml:mn></mml:msup><mml:mtext>Ni</mml:mtext></mml:mrow></mml:math> , Cr, Cu, Zr, Cd, Hf, W, Au, Pb and Bi are presented. It includes new fission yields, prompt fission neutron spectra and average number of neutrons per fission. In addition, new data for radioactive decay, thermal neutron scattering, gamma-ray emission, neutron activation, delayed neutrons and displacement damage are presented. JEFF-3.3 was complemented by files from the TENDL project. The libraries for photon, proton, deuteron, triton, helion and alpha-particle induced reactions are from TENDL-2017. The demands for uncertainty quantification in modeling led to many new covariance data for the evaluations. A comparison between results from model calculations using the JEFF-3.3 library and those from benchmark experiments for criticality, delayed neutron yields, shielding and decay heat, reveals that JEFF-3.3 performes very well for a wide range of nuclear technology applications, in particular nuclear energy.
Stable dispersion of reduced graphene in various organic solvents was achieved via noncovalent functionalization with amine-terminated polymers. An aqueous dispersion of reduced graphene was prepared by chemical reduction of graphene oxide in aqueous media and was vacuum filtered to generate reduced graphene sheets. Good solvents and nonsolvents for the dried reduced graphene were evaluated using a solubility test. To achieve stable dispersion in the evaluated nonsolvents, amine-terminated polystyrene was noncovalently functionalized to the graphene, while graphene sheets were phase transferred via sonication from aqueous phase to the organic nonsolvent phase, including the amine-terminated polymers. Thorough FTIR and Raman spectroscopy investigation verified that the protonated amine terminal group of polystyrene underwent noncovalent functionalization to the carboxylate groups at the graphene surface, providing the high dispersibility in various organic media.
The PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) has measured electrons with $0.3<{p}_{T}<9\text{ }\text{ }\mathrm{GeV}/c$ at midrapidity ($|y|<0.35$) from heavy-flavor (charm and bottom) decays in $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{{s}_{\mathrm{NN}}}=200\text{ }\text{ }\mathrm{GeV}$. The nuclear modification factor ${R}_{\mathrm{AA}}$ relative to $p+p$ collisions shows a strong suppression in central $\mathrm{Au}+\mathrm{Au}$ collisions, indicating substantial energy loss of heavy quarks in the medium produced at RHIC energies. A large azimuthal anisotropy ${v}_{2}$ with respect to the reaction plane is observed for $0.5<{p}_{T}<5\text{ }\text{ }\mathrm{GeV}/c$ indicating substantial heavy-flavor elliptic flow. Both ${R}_{\mathrm{AA}}$ and ${v}_{2}$ show a ${p}_{T}$ dependence different from those of neutral pions. A comparison to transport models which simultaneously describe ${R}_{\mathrm{AA}}({p}_{T})$ and ${v}_{2}({p}_{T})$ suggests that the viscosity to entropy density ratio is close to the conjectured quantum lower bound, i.e., near a perfect fluid.
New iron-based mixed-polyanion compounds LixNa4-xFe3(PO4)(2)(P2O7) (x = 0-3) were synthesized, and their crystal structures were determined. The new compounds contained three-dimensional (3D)-sodium/lithium paths supported by P2O7 pillars in the crystal. First principles calculations identified the complex 3D paths with their activation barriers and revealed them as fast ionic conductors. The reversible electrode operation was found in both Li and Na cells with capacities of one-electron reaction per Fe atom, 140 and 129 mAh g(-1), respectively. The redox potential of each phase was similar to 3.4 V (vs Li) for the Li-ion cell and similar to 3.2 V (vs Na) for the Na-ion cell. The properties of high power, small volume change, and high thermal stability were also recognized, presenting this new compound as a potential competitor to other iron-based electrodes such as Li2FeP2O7, Li2FePO4F, and LiFePO4.
The PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC)has measured $J/\ensuremath{\psi}$ production for rapidities $\ensuremath{-}2.2<y<2.2$ in $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{{s}_{NN}}=200\text{ }\text{ }\mathrm{GeV}$. The $J/\ensuremath{\psi}$ invariant yield and nuclear modification factor ${R}_{AA}$ as a function of centrality,transverse momentum, and rapidity are reported. A suppression of $J/\ensuremath{\psi}$ relative to binary collision scaling of proton-protonreaction yields is observed. Models which describe the lower energy $J/\ensuremath{\psi}$ data at the CERN Super Proton Synchrotron invoking only $J/\ensuremath{\psi}$ destruction based on the local medium density predicta significantly larger suppression at RHIC and more suppression at midrapiditythan at forward rapidity. Both trends are contradicted by our data.
The production of ${e}^{+}{e}^{\ensuremath{-}}$ pairs for ${m}_{{e}^{+}{e}^{\ensuremath{-}}}<0.3\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ and $1<{p}_{T}<5\text{ }\text{ }\mathrm{GeV}/c$ is measured in $p+p$ and $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{{s}_{NN}}=200\text{ }\text{ }\mathrm{GeV}$. An enhanced yield above hadronic sources is observed. Treating the excess as photon internal conversions, the invariant yield of direct photons is deduced. In central $\mathrm{Au}+\mathrm{Au}$ collisions, the excess of the direct photon yield over $p+p$ is exponential in transverse momentum, with an inverse slope $T=221\ifmmode\pm\else\textpm\fi{}{19}^{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{19}^{\mathrm{syst}}\text{ }\text{ }\mathrm{MeV}$. Hydrodynamical models with initial temperatures ranging from ${T}_{\mathrm{init}}\ensuremath{\sim}300--600\text{ }\text{ }\mathrm{MeV}$ at times of $\ensuremath{\sim}0.6--0.15\text{ }\text{ }\mathrm{fm}/c$ after the collision are in qualitative agreement with the data. Lattice QCD predicts a phase transition to quark gluon plasma at $\ensuremath{\sim}170\text{ }\text{ }\mathrm{MeV}$.
Abstract Laser‐induced graphene (LIG) is a newly emerging 3D porous material produced when irradiating a laser beam on certain carbon materials. LIG exhibits high porosity, excellent electrical conductivity, and good mechanical flexibility. Predesigned LIG patterns can be directly fabricated on diverse carbon materials with controllable microstructure, surface property, electrical conductivity, chemical composition, and heteroatom doping. This selective, low‐cost, chemical‐free, and maskless patterning technology minimizes the usage of raw materials, diminishes the environmental impact, and enables a wide range of applications ranging from academia to industry. In this review, the recent developments in 3D porous LIG are comprehensively summarized. The mechanism of LIG formation is first introduced with a focus on laser‐material interactions and material transformations during laser irradiation. The effects of laser types, fabrication parameters, and lasing environment on LIG structures and properties are thoroughly discussed. The potentials of LIG for advanced applications including biosensors, physical sensors, supercapacitors, batteries, triboelectric nanogenerators, and so on are also highlighted. Finally, current challenges and future prospects of LIG research are discussed.
Maricite NaFePO<sub>4</sub>can function as an excellent cathode material for Na ion batteries, an unexpected result since it has been regarded as an electrochemically inactive electrode for rechargeable batteries.
Compounds with a mixed polyanion framework have recently gained attention as a new class of compounds for material exploration. The potential tunability of the structure by using various combinations of polyanions can potentially lead to a novel cathode. However, the redox reaction in complex structures often involves complex structural evolutions during the electrochemical reaction, which require careful analysis. We investigated the electrochemical mechanism of NaxFe3(PO4)2(P2O7) (1 ≤ x ≤ 4), which was recently proposed as a promising mixed-polyanion cathode for Na rechargeable batteries, using first principles calculations and experiments. We discovered that the de/sodiation of the NaxFe3(PO4)2(P2O7) electrode occurs via a one-phase reaction with a reversible Fe2+/Fe3+ redox reaction and accompanies an exceptionally small volumetric change of less than 4%. Na ion intercalation usually induces a large volumetric change in conventional systems; therefore, this small volume change is unusual and was attributed to the open framework of polyanion compounds with P2O7 dimers that are capable of rotating and distorting to accommodate the structural change. Structural robustness was further observed at even highly charged states at temperatures as high as 530 °C from in situ X-ray diffraction (XRD) and differential scanning calorimetry (DSC). We believe that the improved understanding of the electrochemical mechanism provided here will expedite the optimization of the new Na4Fe3(PO4)2(P2O7) electrode for Na rechargeable batteries.
Differential measurements of elliptic flow (${v}_{2}$) for $\mathrm{Au}+\mathrm{Au}$ and $\mathrm{Cu}+\mathrm{Cu}$ collisions at $\sqrt{{s}_{\mathrm{NN}}}=200\text{ }\text{ }\mathrm{GeV}$ are used to test and validate predictions from perfect fluid hydrodynamics for scaling of ${v}_{2}$ with eccentricity, system size, and transverse kinetic energy (${\mathrm{KE}}_{T}$). For ${\mathrm{KE}}_{T}\ensuremath{\equiv}{m}_{T}\ensuremath{-}m$ up to $\ensuremath{\sim}1\text{ }\text{ }\mathrm{GeV}$ the scaling is compatible with hydrodynamic expansion of a thermalized fluid. For large values of ${\mathrm{KE}}_{T}$ mesons and baryons scale separately. Quark number scaling reveals a universal scaling of ${v}_{2}$ for both mesons and baryons over the full ${\mathrm{KE}}_{T}$ range for $\mathrm{Au}+\mathrm{Au}$. For $\mathrm{Au}+\mathrm{Au}$ and $\mathrm{Cu}+\mathrm{Cu}$ the scaling is more pronounced in terms of ${\mathrm{KE}}_{T}$, rather than transverse momentum.
The electrochemical properties of Na3V2(PO4)2F3 in a Na rechargeable battery were investigated through a combined computational and experimental study. Ex situ XRD results indicate that the reversible sodiation/desodiation occurs via one phase reaction and the structure of Na3−xV2(PO4)2F3 remains quite stable upon extraction and insertion of sodium. Notable is that the one phase reaction is accompanied by the negligible variation in lattice parameters (∼1%) and unit cell volume (∼2%) which results in a good cycle performance. It is further noticed that the desodiated phase is thermally stable up to 550 °C implying the excellent safety characteristic of the charged electrode. The first principles calculations elucidate the mechanisms of the structural evolution and the electrochemical behavior of Na3−xV2(PO4)2F3 upon battery cycling.
The photostability of rhodamine 6G, rhodamine 610 and pyrromethene 567 in solutions, wet-gel and dried sol-gel host media has been determined. A method for the synthesis of xerogel monoliths has been modified to reduce the preparation time for the doped sol-gel samples, and high optical quality sol-gel samples doped with laser dyes have been prepared. A high efficiency and photostability is observed for xanthene laser dyes in wet and dried sol-gel phases but not for a pyrromethene laser dye.
Room‐temperature Na‐ion batteries (NIBs) have recently attracted attention as potential alternatives to current Li‐ion batteries (LIBs). The natural abundance of sodium and the similarity between the electrochemical properties of NIBs and LIBs make NIBs well suited for applications requiring low cost and long‐term reliability. Here, the first successful synthesis of a series of Na 3 (VO 1− x PO 4 ) 2 F 1+2 x (0 ≤ x ≤ 1) compounds as a new family of high‐performance cathode materials for NIBs is reported. The Na 3 (VO 1− x PO 4 ) 2 F 1+2 x series can function as high‐performance cathodes for NIBs with high energy density and good cycle life, although the redox mechanism varies depending on the composition. The combined first‐principles calculations and experimental analysis reveal the detailed structural and electrochemical mechanisms of the various compositions in solid solutions of Na 3 (VOPO 4 ) 2 F and Na 3 V 2 (PO 4 ) 2 F 3 . The comparative data for the Na y (VO 1− x PO 4 ) 2 F 1+2 x electrodes show a clear relationship among V 3+ /V 4+ /V 5+ redox reactions, Na + −Na + interactions, and Na + intercalation mechanisms in NIBs. The new family of high‐energy cathode materials reported here is expected to spur the development of low‐cost, high‐performance NIBs.
An experiment to search for light sterile neutrinos is conducted at a reactor with a thermal power of 2.8 GW located at the Hanbit nuclear power complex. The search is done with a detector consisting of a ton of Gd-loaded liquid scintillator in a tendon gallery approximately 24 m from the reactor core. The measured antineutrino event rate is 1976 per day with a signal to background ratio of about 22. The shape of the antineutrino energy spectrum obtained from the eight-month data-taking period is compared with a hypothesis of oscillations due to active-sterile antineutrino mixing. No strong evidence of 3+1 neutrino oscillation is found. An excess around the 5 MeV prompt energy range is observed as seen in existing longer-baseline experiments. The mixing parameter sin^{2}2θ_{14} is limited up to less than 0.1 for Δm_{41}^{2} ranging from 0.2 to 2.3 eV^{2} with a 90% confidence level.
Azimuthal angle (Delta phi) correlations are presented for a broad range of transverse momentum (0.4 < p(T) < 10 GeV/c) and centrality (0-92%) selections for charged hadrons from dijets in Au+Au collisions at root s(NN) = 200 GeV. With increasing p(T), the away-side Delta phi distribution evolves from a broad and relatively flat shape to a concave shape, then to a convex shape. Comparisons with p + p data suggest that the away-side distribution can be divided into a partially suppressed "head" region centered at Delta phi similar to pi, and an enhanced "shoulder" region centered at Delta phi similar to pi +/- 1.1. The p(T) spectrum for the associated hadrons in the head region softens toward central collisions. The spectral slope for the shoulder region is independent of centrality and trigger p(T). The properties of the near-side distributions are also modified relative to those in p + p collisions, reflected by the broadening of the jet shape in Delta phi and Delta eta, and an enhancement of the per-trigger yield. However, these modifications seem to be limited to p(T)less than or similar to 4 GeV/c, above which both the hadron pair shape and per-trigger yield become similar to p + p collisions. These observations suggest that both the away- and near-side distributions contain a jet fragmentation component which dominates for p(T) greater than or similar to 5 GeV/c and a medium-induced component which is important for p(T) less than or similar to 4 GeV/c. We also quantify the role of jets at intermediate and low p(T) through the yield of jet-induced pairs in comparison with binary scaled p + p pair yield. The yield of jet-induced pairs is suppressed at high pair proxy energy (sum of the p(T) magnitudes of the two hadrons) and is enhanced at low pair proxy energy. The former is consistent with jet quenching; the latter is consistent with the enhancement of soft hadron pairs due to transport of lost energy to lower p(T).
PHENIX has measured the ${e}^{+}{e}^{\ensuremath{-}}$ pair continuum in $\sqrt{{s}_{\mathit{NN}}}=200$ GeV $\mathrm{Au}+\mathrm{Au}$ and $p+p$ collisions over a wide range of mass and transverse momenta. The ${e}^{+}{e}^{\ensuremath{-}}$ yield is compared to the expectations from hadronic sources, based on PHENIX measurements. In the intermediate-mass region, between the masses of the $\ensuremath{\phi}$ and the $J/\ensuremath{\psi}$ meson, the yield is consistent with expectations from correlated $c\mathrm{c\ifmmode \bar{}\else \={}\fi{}}$ production, although other mechanisms are not ruled out. In the low-mass region, below the $\ensuremath{\phi}$, the $p+p$ inclusive mass spectrum is well described by known contributions from light meson decays. In contrast, the $\mathrm{Au}+\mathrm{Au}$ minimum bias inclusive mass spectrum in this region shows an enhancement by a factor of $4.7\ifmmode\pm\else\textpm\fi{}{0.4}^{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{1.5}^{\mathrm{syst}}\ifmmode\pm\else\textpm\fi{}{0.9}^{\mathrm{model}}$. At low mass (${m}_{\mathit{ee}}<0.3$ GeV/${c}^{2}$) and high ${p}_{T}$ ($1<{p}_{T}<5$ GeV/$c$) an enhanced ${e}^{+}{e}^{\ensuremath{-}}$ pair yield is observed that is consistent with production of virtual direct photons. This excess is used to infer the yield of real direct photons. In central $\mathrm{Au}+\mathrm{Au}$ collisions, the excess of the direct photon yield over the $p+p$ is exponential in ${p}_{T}$, with inverse slope $T=221\ifmmode\pm\else\textpm\fi{}{19}^{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{19}^{\mathrm{syst}}$ MeV. Hydrodynamical models with initial temperatures ranging from ${T}_{\mathrm{init}}\ensuremath{\simeq}300--600$ MeV at times of $0.6--0.15$ fm/$c$ after the collision are in qualitative agreement with the direct photon data in $\mathrm{Au}+\mathrm{Au}$. For low ${p}_{T}<1$ GeV/$c$ the low-mass region shows a further significant enhancement that increases with centrality and has an inverse slope of $T\ensuremath{\simeq}100$ MeV. Theoretical models underpredict the low-mass, low-${p}_{T}$ enhancement.