New Network Polymer Electrolytes Based on Ionic Liquid and SiO 2 Nanoparticles for Energy Storage Systems.

Elementary processes of electro mass transfer in the nanocomposite polymer electrolyte system by pulse field gradient, spin echo NMR spectroscopy and the high-resolution NMR method together with electrochemical impedance spectroscopy are examined. The new nanocomposite polymer gel electrolytes consisted of polyethylene glycol diacrylate (PEGDA), salt LiBF 4 and 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF 4 ) and SiO 2 nanoparticles. Kinetics of the PEGDA matrix formation was studied by isothermal calorimetry. The flexible polymer-ionic liquid films were studied by IRFT spectroscopy, differential scanning calorimetry and temperature gravimetric analysis. The total conductivity in these systems was about 10 -4 S cm -1 (-40 °C), 10 -3 S cm -1 (25 °C) and 10 -2 S cm -1 (100 °C). The method of quantum-chemical modeling of the interaction of SiO 2 nanoparticles with ions showed the advantage of the mixed adsorption process, in which a negatively charged surface layer is formed from Li + BF 4 - ions on silicon dioxide particles and then from ions of the ionic liquid EMI + BF 4 - . These electrolytes are promising for use both in lithium power sources and in supercapacitors. The paper shows preliminary tests of a lithium cell with an organic electrode based on a pentaazapentacene derivative for 110 charge-discharge cycles.