A Novel Nanocomposite Polymer Electrolyte for Application in Solid State Lithium Ion Battery

Nanocomposite polymer electrolytes (NCPE) have been prepared by blending poly(ethylene oxide) (PEO) and polyhedral oligomeric silsesquioxane-functionalized with poly(ethylene glycol) (POSS-PEG) with lithium bis(oxalate) borate (LiBOB). Different thermal, electrical and electrochemical studies exhibit promising characteristics of these polymer electrolytes, suitable as electrolytes in rechargeable lithium-ion batteries. POSS-PEG was highly compatible with PEO up to 50 wt% and resulted in single Tg and increased ionic conductivity. The ionic conductivity of the nanocomposites increased to 3.98 x 10(-6) S/cm at 50 wt% of POSS-PEG by more than 2 orders of magnitude. POSS-PEG nanoparticles sustainably increased ionic conductivity without impeding chain motion of polymer and were highly compatible with PEO up to 50 wt% of POSS-PEG, which can mitigate the restriction of the amount of nanoparticles introduction. The Li/PEO-LiBOB-POSS PEG/LiFePO4 coin typed cell cycled at 0.1 C shows the 14 discharge capacity about 146 mAh g(-1), and remains 126.2 mAh g(-1) on the 50th cycle. Overall, these results indicate that POSS-PEG nanocomposites can be potentially useful as a new class of nanocomposite polymer electrolytes for rechargeable lithium batteries.