# Increased lithium-ion conductivity in $(PEG)_{46}LiClO_4$ solid polymer electrolyte with $\delta-Al_2O_3$ nanoparticles

Singh, Joykumar Th and Bhat, SV (2004) Increased lithium-ion conductivity in $(PEG)_{46}LiClO_4$ solid polymer electrolyte with $\delta-Al_2O_3$ nanoparticles. In: Journal of Power Sources, 129 (2). pp. 280-287.

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## Abstract

The effect of $\delta-Al_2O_3$ nanoparticles (size ~ 10 nm) on the ionic conductivity and related properties of a solid polymer electrolyte (SPE) that consists of low molecular weight (Mw = 2000) poly(ethylene) glycol (PEG) complexed with $LiClO_4$ is studied in detail using XRD, DSC, TPD, NMR, and complex impedance methods. The maximum ionic conductivity $\delta= 7.3\times10^{-7} S cm^{-1}$ observed for pristine $(PEG)_{46}LiClO_4$ is found to be dependent on the content of $\delta-Al_2O_3$ filter; it shows a peak value of $\delta= 4.5\times10^{-6} S cm^{-1}$ for 10 mol% filler. This is nearly an order of magnitude enhancement of the ionic conductivity and is found by DSC studies to be related to a decrease in the crystalline regions in the SPE, while the glass transition temperature $T_g$ and the melting temperature $T_m$ remain essentially unchanged. $^7Li NMR$ motional narrowing points to an increase in the effective mobility of the lithium ions on doping with the nanoparticles. The temperature dependence of \delta can be divided into two regions, one consistent with the Arrhenius behavior and the other with the Vogel, Tamman and Fulcher equation. The activation energy is found to be the lowest for the 10 mol% doped sample. It is concluded that doping with nanoparticles leads to an enhancement of conductivity due to a decrease in the crystallinity and the activation energy, as well as to an increase in the effective mobility of Li ions.

Item Type: Journal Article The copyright belongs to Elsevier. Nanocomposite polymer electrolyte;Ionic conductivity;Acidic 8-Al2O3;Glass transition temperature;7Li NMR Division of Physical & Mathematical Sciences > Physics 19 May 2006 19 Sep 2010 04:26 http://eprints.iisc.ernet.in/id/eprint/6748