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Nanoparticle-dispersed polymer electrolytes have been prepared by stirring or high-energy ball milling of polyethylene oxide (PEO), lithium salt (LiCF3SO3, LiClO4 and LiPF6), and nanometer-size ceramic powder (TiO2, SiO2 and Al2O3). The smaller the size of ceramic particles, the better they influence the crystallization kinetics of the PEO polymer chains. High-energy ball milling lowers the glass transition temperature of the composite polymers, and thus increases the ionic conductivity greater than the order of the magnitude compared with the un-milled samples. The highest ionic conductivity was reported when using LiPF6 as added lithium salt and Al2O3 as dispersed particle. Cyclic voltametric measurements showed that the PEO-system is electrochemically stable in the range of 2–5 V. [Copyright &y& Elsevier]

Abstract: Nanosize cobalt sulfides were synthesized through a one step chemical reaction method at room temperature. The cobalt sulfide nanopowders were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electron microscopy and electrochemical testing. The results revealed that the cobalt sulfide is a semiconductor; the reversible capacity is increased with increasing content of electronic conductors in the active material of electrodes. The as prepared sample with 10wt.% carbon black and 10wt.% polypyrrole (PPy) powder as electronic conductors shows the best electrochemical properties, with a reversible capacity of over 300mAhg−1 based on the total mass of the electrode. Cobalt sulfide nanopowders show promise as cathode active materials for lithium-rechargeable batteries. [Copyright &y& Elsevier]