Room-temperature cycling of metal fluoride electrodes: Liquid electrolytes for high-energy fluoride ion cells.

Fluoride ion batteries are potential "next-generation" electrochemical storage devices that offer high energy density. At present, such batteries are limited to operation at high temperatures because suitable fluoride ion-conducting electrolytes are known only in the solid state. We report a liquid fluoride ion-conducting electrolyte with high ionic conductivity, wide operating voltage, and robust chemical stability based on dry tetraalkylammonium fluoride salts in ether solvents.

Intrinsic Chirality Origination in Carbon Nanotubes.

Elucidating the origin of carbon nanotube chirality is key for realizing their untapped potential. Currently, prevalent theories suggest that catalyst structure originates chirality via an epitaxial relationship. Here we studied chirality abundances of carbon nanotubes grown on floating liquid Ga droplets, which excludes the influence of catalyst features, and compared them with abundances grown on solid Ru nanoparticles.

Room-temperature chemical synthesis of shape-controlled indium nanoparticles.

Shape-controlled metal nanoparticles are of interest because of their wide range of properties that are useful for applications that include optics, electronics, magnetism, and catalysis. Indium metal is an attractive target for nanoparticle synthesis because it is superconducting, plasmonically active, and is a component in low-melting solders and solid-state lubricants. Indium nanoparticles are typically synthesized using harsh physical or chemical techniques, and rigorous shape control is difficult.

Shape-controlled conversion of beta-Sn nanocrystals into intermetallic M-Sn (M=Fe, Co, Ni, Pd) nanocrystals.

The ability to control the shape of metal nanocrystals is critical to applications such as catalysis, magnetism, and plasmonics. Despite significant advances in controlling the shapes of single-metal nanocrystals, rigorous shape control of multimetal nanocrystals remains challenging, and has been limited largely to alloy systems of similar metals. Here we describe a robust strategy that produces shape-controlled intermetallic nanocrystals involving elements of notably different reduction potentials, reduction kinetics, and reactivity.

Reactivity of 3d transition metal cations in diethylene glycol solutions. Synthesis of transition metal ferrites with the structure of discrete nanoparticles complexed with long-chain carboxylate anions.

Study of the reactivity of 3d transition metal cations in diethylene glycol solutions revealed several key features that made it possible to develop a new method for synthesis of the nanocrystalline transition metal ferrites. The 3-7 nm particles of [MFe2O4]n[O2CR]m, where M = Mn, Fe, Co, Ni, and Zn, ligated on their surface with long-chain carboxylate anions, have been obtained in an isolated yield of 75-90%. The key features are the following.