The mechanism of conductivity of liquid polymer electrolytes

Abstract

Conductivities and viscosities of solutions of Li, Na and K thiocyanates in low-molecular-weight liquid copolymers of ethylene oxide and propylene oxide have been measured. The curves of molar conductance us. c5 show well defined maxima and minima. The conductivity is independent of copolymer molecular weight but is enhanced by raising the EO content of the copolymer. The results are interpreted in terms of a model in which the effects of ion association and re-dissociation play an important role. It is suggested that the characteristic properties of liquid polymer electrolytes can be satisfactorily explained only if the current is largely anionic.

Effect of storage time on the properties of PVA–KOH alkaline solid polymer electrolyte system

“…The slow increase in σ (after P-20 K) implies that the number of available mobile ions is not increasing in the same proportion as the doping concentration. This could be explained by the basis of ion association [24,25]. As the salt concentration increases, the free ions become closer with an increase in columbic attraction between them.…”

Solvation of Cobalt Salts by Oligomeric Polyethers

“…This phenomenon has been observed for several salt-polyether systems [3,9,10] and is attributed to the coupling of the mobility of the charged species with solution viscosity. In simple terms, although increasing the salt concentration increases the number of charged species available to carry current, the solution viscosity increases as well, making macroscopic charge transport more difficult.…”

“…It can be seen that the viscosities increase dramatically with increasing salt content for both oligomers. In contrast, Cameron et al [10,11] find very little effect on viscosity until approximately IM salt content for alkali metal thiocyanate-EO/PO copolymer systems. Our results indicate that the complexation of the divalent cobalt salt greatly stiffens the oligomer chains, perhaps due to a strong intrmolecular "crosslinking" effect.…”

Ion-polymer interactions in gel electrolytes studied by ESR spectroscopy of spin probes and spin labels

“…The Li`ions are coordinated by carbonyl oxygens on the ester side groups of the PMMA, and the ions are acting as ClO 4 transient crosslinks (see also ref. 13).…”