Effect of POSS-PEG hybrid nanoparticles on cycling performance of polyether-LiDFOB based solid polymer electrolytes for all solid-state Li-ion battery applications

Abstract

Abstract For the first time, the consequences of organic-inorganic hybrid nanoparticle polyhedral oligomeric silsesquioxane-polyethylene glycol (POSS-PEG(n = 4)) on the physicochemical and electrochemical properties of poly(ethylene oxide) (PEO)-lithium difluoro(oxalato)borate (LiDFOB) based nanocomposite solid polymer electrolyte (NSPE) membranes were systematically prepared and utilized as an active separator for battery applications. The thermal stability and structural properties of the prepared NSPE membranes were analyzed by means of differential scanning calorimetry (DSC), thermogravimetry (TG) and X-ray diffraction (XRD) analyses. The morphological changes by POSS-PEG in polymer electrolyte membranes were investigated by field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The incorporation of POSS-PEG greatly enhanced the ionic conductivity, mechanical integrity and compatibility. The maximum ambient temperature ionic conductivity was found to be in the range of 7.28 × 10−5 S/cm for 40 wt% POSS-PEG. Finally, the solid state lithium cell was assembled as Li/NSPE/LiCoO2. The cell delivered a maximum discharge capacity of 187 mAh g−1 at 0.1C-rate with very good capacity retention up to 50 cycles. The test results indicated that the electrolyte is found to be a better candidate than those reported earlier.