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A potassium iron (II) hexacyanoferrate nanocube cathode material is reported, which operates with an aqueous electrolyte to deliver exceptionally high capacities (up to 120 mA h g ). The cathode material exhibits excellent structural integrity, leading to fast kinetics and highly reversible properties. All of the battery materials are safe, inexpensive, and provide superior high-rate, long-cycle-life electrochemical performance.

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Gold nanorods have significant technological potential and are of broad interest to the nanotechnology community. The discovery of the seeded, wet-chemical synthetic process to produce them may be regarded as a landmark in the control of metal nanoparticle shape. However, the mechanism by which the initial spherical gold seeds acquire anisotropy is a critical, yet poorly understood, factor. Here we examine the very early stages of rod growth using a combination of techniques including cryogenic transmission electron microscopy, optical spectroscopy, and computational modeling. Reconciliation of the available experimental observations can only be achieved by invoking a stochastic, "popcorn"-like mechanism of growth, in which individual seeds lie quiescent for some time before suddenly and rapidly growing into rods. This is quite different from the steady, concurrent growth of nanorods that has been previously generally assumed. Furthermore we propose that the shape is controlled by the ratio of surface energy of rod sides to rod ends, with values of this quantity in the range of 0.3-0.8 indicated for typical growth solutions.

RECEIVED DATE Adsorption of Amine Compounds on the Au (111)

Density functional calculations of the adsorption of ethynylbenzene on the Au(111) surface show that, after cleavage of the C-H bond, the terminal carbon makes a strong covalent bond to the surface. The bond energy is shown to be about 70 kcal.mol(-1) with the fcc hollow site being most stable and the molecule oriented perpendicular to the surface. Adsorption without elimination of hydrogen is also possible via a hydrogen 1,2 shift to form a vinylidene surface-bound species, or opening of the C-C triple bond and adsorption through the two carbon atoms in a flat conformation. The reaction energy for formation of the surface-bound vinylidene is estimated to be 5 kcal.mol(-1) exothermic relative to the isolated ethynylbenzene and gold substrate.

Due to the high theoretical specific energy, the lithium–oxygen battery has been heralded as a promising energy storage system for applications such as electric vehicles. However, its large over-potentials during discharge–charge cycling lead to the formation of side-products, and short cycle life. Herein, we report an ionic liquid bearing the redox active 2,2,6,6-tetramethyl-1-piperidinyloxy moiety, which serves multiple functions as redox mediator, oxygen shuttle, lithium anode protector, as well as electrolyte solvent. The additive contributes a 33-fold increase of the discharge capacity in comparison to a pure ether-based electrolyte and lowers the over-potential to an exceptionally low value of 0.9 V. Meanwhile, its molecule facilitates smooth lithium plating/stripping, and promotes the formation of a stable solid electrolyte interface to suppress side-reactions. Moreover, the proportion of ionic liquid in the electrolyte influences the reaction mechanism, and a high proportion leads to the formation of amorphous lithium peroxide and a long cycling life (> 200 cycles). In particular, it enables an outstanding electrochemical performance when operated in air.