Solvation of Cobalt Salts by Oligomeric Polyethers

Abstract

Der *1SOeIftun te t orw nIe n e or a rernwu-strfLmcm. warct."q evujing uJia wĩ ll iii I IOfI t n U.rmaotierrnluan commnts rciaunfts woetmateor ano otewr~oc f " , m Va uoge . p ,,se ,-o i ited ucson p,,ect 10 44 1u ). W sn gto OC OSO) . *3 * . n* r , REPORT TYPE AND DATES COVERED ABSTRACT (Maximum 200 words)Polyether-salt systems involving CoBr 2 dissolved in oligomenc polyethylene glycol (PEG) and polytetramethylene glycol (PTMG) have been investigated. Both systems demonstrated conductivity maxima as a function of salt concentration. PTMG electrolytes had dramatically lower conductivities (max. a -3.6 x 10 -7 Scm for PTMG, max. a -1.45 x I0 -Scm for PEG at room temperature) which can be explained on the basis of spectral data which indicate the existence of predominantly neutral species in PTMG. The reason for the difference in the types of species present in PEG and PTMG can be rationalized on the basis of the chelate effect. Reproduction in whole or in part is permitted for any purpose of the United States Government. 92-23985This document has been approved for public release and sale; its distribution is unlimited. Solvation of Cobalt Salts

Ion Conduction and Water Transport in Polyphosphazene-Based Multilayers

“…Often, high ionic conductivity values are achieved by utilizing polymers with low glass-transition temperatures and low degrees of crystallization, at the expense of mechanical durability. Poly(ethylene oxide) (PEO) has been one of the most thoroughly investigated polymer electrolytes because it bears cation-solvating ether groups and a flexible backbone for facile ion mobility. − However, its crystallinity and limited chemical stability are major limitations for realistic applications. To minimize crystallization, researchers have used small molecule plasticizers with PEO in lithium-ion batteries; however, these plasticizers are typically highly flammable and result in a more liquidlike electrolyte system, both of which lead to serious hazards if a device were to be breached.…”