Monodisperse Antimony Nanocrystals for High-Rate Li-ion and Na-ion Battery Anodes: Nano versus Bulk

We report colloidal synthesis of antimony (Sb) nanocrystals with mean size tunable in the 10–20 nm range and with narrow size distributions of 7–11%. In comparison to microcrystalline Sb, 10 and 20 nm Sb nanocrystals exhibit enhanced rate-capability and higher cycling stability as anode materials in rechargeable Li-ion and Na-ion batteries. All three particle sizes of Sb possess high and similar Li-ion and Na-ion charge storage capacities of 580–640 mAh g^–1 at moderate charging/discharging current densities of 0.5–1C (1C-rate is 660 mA g^–1). At all C-rates (0.5–20C, e.g. current densities of 0.33–13.2 Ag^1–), capacities of 20 nm Sb particles are systematically better than for both 10 nm and bulk Sb. At 20C-rates, retention of charge storage capacities by 10 and 20 nm Sb nanocrystals can reach 78–85% of the low-rate value, indicating that rate capability of Sb nanostructures can be comparable to the best Li-ion intercalation anodes and is so far unprecedented for Na-ion storage

Efficient and Inexpensive Sodium–Magnesium Hybrid Battery

We present a hybrid intercalation battery based on a sodium/magnesium (Na/Mg) dual salt electrolyte, metallic magnesium anode, and a cathode based on FeS₂ nanocrystals (NCs). Compared to lithium or sodium, metallic magnesium anode is safer due to dendrite-free electroplating and offers extremely high volumetric (3833 mAh cm^–3) and gravimetric capacities (2205 mAh g^–1). Na-ion cathodes, FeS₂ NCs in the present study, may serve as attractive alternatives to Mg-ion cathodes due to the higher voltage of operation and fast, highly reversible insertion of Na-ions. In this proof-of-concept study, electrochemical cycling of the Na/Mg hybrid battery was characterized by high rate capability, high Coulombic efficiency of 99.8%, and high energy density. In particular, with an average discharge voltage of ∼1.1 V and a cathodic capacity of 189 mAh g^–1 at a current of 200 mA g^–1, the presented Mg/FeS₂ hybrid battery delivers energy densities of up to 210 Wh kg^–1, comparable to commercial Li-ion batteries and approximately twice as high as state-of-the-art Mg-ion batteries based on Mo₆S₈ cathodes. Further significant gains in the energy density are expected from the development of Na/Mg electrolytes with a broader electrochemical stability window. Fully based on Earth-abundant elements, hybrid Na–Mg batteries are highly promising for large-scale stationary energy storage

Effects of heroin on brain perfusion in contrast to placebo.

<p>BA: Brodmann area; L: left; P: perfusion; R: right; WM: white matter;</p>*<p>: p≤0.05;</p>***<p>: p≤0.001.</p><p>Each coordinate triple is a peak area of contrast intensity in one of the two significant clusters and refers to a specific area defined in the atlas of Talairach & Tournoux (1988).</p

Regional perfusion values of significant clusters.

<p>ACC: Anterior cingulate cortex; CI: Confidence interval; MPFC: Medial prefrontal cortex.</p

Physiological parameters after heroin and placebo administration.

<p>BP: Blood pressure; **: p<0.01.</p

Psychological effects of heroin.

<p>HCQ: Heroin Craving Questionnaire; SaO₂: Blood oxygen saturation; SD: Standard deviation; VAS: Visual Analogue Scale;</p>*<p>: p<0.05.</p

Monodisperse and Inorganically Capped Sn and Sn/SnO₂ Nanocrystals for High-Performance Li-Ion Battery Anodes

We report a facile synthesis of highly monodisperse colloidal Sn and Sn/SnO₂ nanocrystals with mean sizes tunable over the range 9–23 nm and size distributions below 10%. For testing the utility of Sn/SnO₂ nanocrystals as an active anode material in Li-ion batteries, a simple ligand-exchange procedure using inorganic capping ligands was applied to facilitate electronic connectivity within the components of the nanocrystalline electrode. Electrochemical measurements demonstrated that 10 nm Sn/SnO₂ nanocrystals enable high Li insertion/removal cycling stability, in striking contrast to commercial 100–150 nm powders of Sn and SnO₂. In particular, reversible Li-storage capacities above 700 mA h g^–1 were obtained after 100 cycles of deep charging (0.005–2 V) at a relatively high current of 1000 mA h g^–1

Altered regional perfusion in heroin in comparison to placebo condition.

<p>A) Relative hypo- (blue) and hyperperfusion (red) in heroin condition projected on an inflated brain (threshold: p<0.05). Hyperperfusion was not significant. B) Significant hypoperfusion (blue) in heroin condition (threshold: p<0.01; FEW corrected p<0.05). The z coordinate shows the position of each slice in reference to the Talairach atlas (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0071461#pone-0071461-t003" target="_blank">Table 3</a>). The medial prefrontal cortex, the anterior cingulate cortex, and the insular cortex are shown in different colors, in order to clarify the spatial relationship to the significant clusters.</p