Ionic conductivity of hybrid films composed of polyacrylonitrile, ethylene carbonate, and LiClO₄

Abstract

The electrical conductivity of hybrid films consisting of polyacrylonitrile (PAN), ethylene carbonate (EC), and LiClO4 was investigated. In these films, EC and LiClO4 are found to be molecularly dispersed in PAN, forming solid solutions over a wide composition range. The ionic character of the electrical conductivity is demonstrated. The conductivity is not correlated with the content of LiClO4 or of PAN, but primarily with the mole ratio [EC]/[LiClO4] in the films. An increase in the [EC]/[LiClO4] ratio enhances the conductivity. When the ratio is about 2, the conductivity attains 10−4–10−5 S cm−1 at 25°C. This change in conductivity results from a change in carrier mobility. PAN makes the films solid without decreasing the carrier mobility. In the hybrid films, the carrier mobility and the macroscopic viscosity are not related by Walden's rule. The high conductivity is due to regions in the film characterized by a low microscopic viscosity. This is determined by the mole ratio [EC]/[LiClO4] and largely controls the carrier mobility.

Sodium-23 NMR and complex impedance studies of gel electrolytes based on poly (acrylonitrile)

“…The dielectric constant is, of course, closely related to the solvating ability of the medium. The dielectric constant of pure PAN has been reported as 6.5 at 298K [1], whereas our measurements yield a value of 4.3.…”

“…Typical liquid electrolytes for lithium battery applications are lithium salts dissolved in propylene carbonate (PC) or a mixture of PC and ethylene carbonate (EC). Some of the matrix polymers employed in gel preparation have been poly(acrylonitrile) (PAN) [1][2][3] or poly(methylmethacrylate) (PMMA) [4,5].…”

“…[1] had an average molecular mass of 9.4 X 10' and that s was measured at a frequency of 60 Hz. Our results for pure PAN show that at low frequencies, the dielectric loss is small but still significant; i.e.…”

Characterization of PEO-PAN hybrid solid polymer electrolytes

“…LiClO 4 . 15 Characterization of the electrolyte film was done in conjunction with lithium metal aimWhile the former SPE film was prepared by solution casting technique, the gel film was prepared ing at a possible application for lithium-based batteries. Also, investigations on lithium cells conby mixing the required quantities of the constituents thoroughly and heating the mixture in a taining PAN electrolyte films are reported.…”

Ion Conducting Behaviour of Nano Dispersed Polymer Gel Electrolytes Containing NH4PF6

“…Polymer gel electrolytes obtained by the immobilization of salt solution with the addition of a suitable polymer matrix are important due to their high ionic conductivity which is higher than for solvent free polymer electrolytes [1][2]. Polymer gel electrolytes containing lithium salts have been widely studied due to their suitability as solid electrolytes in lithium batteries [2][3][4].…”