| dc.description.abstract | A new organic-inorganic hybrid electrolyte was synthesized by bridging two different organic-inorganic groups via silane condensation. Two precursors were formed by reacting (i) tri-block co-polymer poly(propylene glycol)-block -poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether), poly(ethylene glycol diglycidyl ether and (3-glycidoxypropyl)-trimethoxysilane, and (ii) oligo(oxyalkylene)-amines (M-2070) with (3-glycidyloxypropyl)-trimethoxysilane. Both the precursors were coupled via silane condensation. Final hybrid electrolytes were obtained by varying the weight percentages of both the precursors and [O]/[Li] ratios, and characterized by different techniques.
The structure and performance of the polymer electrolytes for lithium ion batteries use, including thermal stability, ionic conductivity, salt dissolvability, surface morphology, electrochemical stability, were studied by thermogravi-metric analyzer (TGA), AC impedance, Fourior transform infaraed spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron spectroscopy (SEM), 13C cross-polarization magic-angle spinning (CPMAS). The Vogel-Tamman-Fulcher (VTF)-like conductivity behavior is observed in the present solid polymer electrolyte (SPE) with a maximum ionic conductivity is 1.15×10-4 Scm-1 at 30°C. Multinuclear NMR techniques are used to provide a microscopic view for the specific interaction between the polymer chains and Li+ cations and their dynamic behaviors. The results of 2D 1H-13C wide-line separation (WISE) and 7Li static line NMR width measurements reveal that the mobility of the 7Li cations are strongly related to a dynamic environment created by the polymer chains motion in the amorphous phase.
Then the swelling ratio and the ionic conductivity of the electrolyte membranes are measured with comercial liquid electrolyte solutions, the gel polymer electrolytes (GPEs) represents the highest ionic conductivity as 6.95 × 10-3 Scm-1 at 30°C and with sufficient electrochemical stability up to 4.1 V. Hence, it can be concluded that this new hybrid polymer system is suitable for use as a GPE in rechargeable lithium batteries.
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