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Thermal stability of the solid electrolyte interface (SEI)-layers formed on graphite, mesocarbon microbeads and carbon-black anodes is shown to be dependent on the type lithium salt used in the electrolyte. Exothermic breakdown of the passivation layers, Addresses: Edstrom K, Uppsala Univ, Angstrom Lab, Dept Chem Mat, POB 538, SE-75121 Uppsala, Sweden. Uppsala Univ, Inst Chem, Dept Organ Chem, SE-75121 Uppsala, Sweden.

A method has been developed to study the mechanisms of the thiocyanato ligand exchange reactions between the redox couple I-/I-3(-) and the ruthenium complex bis(tetrabutylammonium) cis-bis(thiocyanato)bis(2,2 ' -bipyridine-4-carboxylic acid, 4 ' -carboxy, Addresses: Hagfeldt A, Univ Uppsala, Dept Phys Chem, Box 532, SE-75121 Uppsala, Sweden. Univ Uppsala, Dept Phys Chem, SE-75121 Uppsala, Sweden. Univ Uppsala, Dept Mat Chem, Angstrom Lab, SE-75121 Uppsala, Sweden.

Hydrated Al(3+) ions [Al(H(2)O)(n)](3+), n = 1-6, were examined with ab Initio self-consistent field (SCF) calculations. The relative contributions of two-, three-, and higher-body terms to the total interaction energy for an [Al(H(2)O)(6)](3+) complex were calculated The sum of all three-body contributions amounts to - 30% of the sum of all pair-additive contributions and is opposite in sign. The three-body energy contributions were also derived for two types of [Al(H(2)O)(2)](3+) complexes. in the first type, both water molecules reside in the first hydration shell of Al(3+) and in the second type there is one in the first shell and one in the second. Altogether 15,500 triplets were investigated and analytical two- and three-body potential energy functions were derived via a fitting procedure. (C) 1999 John Wiley & Sons, Inc.

Polymer electrolytes based on triblock copolymers of ethylene oxide (EO)/propylene oxide (PO)/ethylene oxide of moderate molecular weight and narrow block-length distributions, doped with M(CF3SO3)(2) and M[N(CF3SO2)(2)](2) (M = Mg, Ca, Sr and Ba), LiCF3SO3 and LiN(CF3SO2)(2) have been investigated using infrared spectroscopy, differential scanning calorimetry and conductivity measurements. The effects of varying the EO/PO block length, composition and temperature on the phase behaviour, ion-pair formation and conductivity of the polymer electrolytes have been studied. A two-phase microstructure has been observed. Ion pairing occurs for the triflate salts and the amount was found to be sensitive to the relative block sizes rather than the molecular weight of the copolymer. Copyright (C) 1996 Elsevier Science Ltd.

The intramolecular OH stretching frequency shift observed for water on formation of 'cation-water...H-bond acceptor' complexes is highly non additive. The uncoupled OH frequency shift has been calculated by ab initio methods for q(+)-OH2 and OH2...q(-) complexes of different geometries and for a series of Mg2+.(H2O)(n)...(H2O)(m) complexes, and we argue that the non-additivity (cooperativity) of the frequency shifts is largely a consequence of the parabolic shape of the frequency versus electric field curves.

The polymer electrolytes M[N(CF3SO2)(2)](2)PEO(n) for M = Mg, Ca, Sr and Ba have been investigated using infra-red spectroscopy, differential scanning calorimetry and impedance spectroscopy. The effects of varying concentration (n = 6-40) and temperature (25-95 degrees C) on the contact ion pair formation and cation coordination have been studied. Contact ion pairs are only found for the most concentrated samples (n < 9). Ion pairs occur with two types of structures: one type is found far samples containing Mg2+ and the other for samples with Ca2+, Sr2+ and Ba2+. The conductivities of the samples are discussed in terms of radii and coordination numbers of the cations.

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