Reference

Highly conductive oriented PEO-based polymer electrolytes

Highly conductive oriented PEO-based polymer electrolytes. Golodnitsky, D.; Livshits, E.; Peled, E. (School of Chemistry, Tel Aviv University, Tel Aviv-Jaffa 69978, Israel). Macromolecular Symposia, 203(4th International Conference on Polymer-Solvent Complexes and Intercalates, 2002), 27-45 (English) 2003 Wiley-VCH Verlag GmbH & Co. KGaA. CODEN: MSYMEC. ISSN: 1022-1360. DOCUMENT TYPE: Journal CA Section: 37 (Plastics Manufacture and Processing) This contribution presents an overview of the study of the effect of stretching on semicryst. and amorphous complexes of poly(ethylene oxide) (PEO) with different salts, such as lithium iodide, lithium trifluoromethanesulfonate, lithium hexafluoroarsenate, lithium bis(oxalato)borate and lithium trifluoromethanesulfonimide. In spite of the conventional belief that ion transport in polymer electrolytes (PE) is mediated primarily by polymer segmental motion, we suggest that ion transport occurs preferentially along the PEO helical axis, at least in the cryst. phase. 90076-65-6 and 244761-29-3 are cas registry numbers of chemicals which are used as reagents here. It was found that the more amorphous the PE, the less its lengthwise cond. is influenced by stretching. It is suggested that the rate-detg. step of ion conduction in semicryst. LiX:P(EO)20, polymer electrolytes below the m.p. (Tm) is "interchain" hopping. .

Improving the Capacity Retention of LiCoO2 Cycled to 4

Improving the Capacity Retention of LiCoO2 Cycled to 4.5 V by Heat-Treatment. Chen, Zhaohui; Dahn, J. R. (Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS B3H 3J5, Can.). Electrochemical and Solid-State Letters, 7(1), A11-A14 (English) 2004 Electrochemical Society. CODEN: ESLEF6. ISSN: 1099-0062. 12190-79-3 and 244761-29-3 which are cas registry numbers are also used here. DOCUMENT TYPE: Journal CA Section: 52 (Electrochemical, Radiational, and Thermal Energy Technology) Impedance growth of LiCoO2 electrodes cycled with an upper cutoff potential of 4.5 V is caused by side reactions involving species on the surface of LiCoO2 and LiPF6-based electrolyte. These detrimental chem. species can apparently be removed by a heat-treatment to 550° because electrodes made with heat-treated materials show excellent capacity retention even when cycled to 4.5 V. The detrimental surface species can be subsequently reformed on heat-treated materials by exposure of LiCoO2 to water, suggesting prolonged air exposure is responsible for their formation on com. samples. .