High-performance electrospun POSS-(PMMA46)8/PVDF hybrid gel polymer electrolytes with PP support for Li-ion batteries

Polyhedral oligomeric silsesquioxane-poly(methyl methacrylate)8 (POSS-PMMA8)/polyvinylidene fluoride (PVDF) hybrid gel polymer electrolyte (HGPE) membranes have been fabricated by using electrospinning along with the use of commercial polypropylene (PP) microporous membranes as its support; the corresponding HGPEs were obtained after being activated into liquid electrolytes. The goal of the study is to incorporate the high mechanical property of microporous PP membrane and superior electrochemical performance of electrospun gel polymer electrolyte to get the high-performance electrolyte for Li-ion battery. As an effective modifier, it is found that the introduction of POSS-polymer plays a vital role in enhancing many properties of HGPEs, and the influence of POSS-(PMMA46)8 content on overall properties of HGPEs is investigated. In specific, the HGPEs membrane with 12 wt% POSS-(PMMA46)8 displays a significant uniform fiber diameter with 720 nm and high electrolyte uptake of 322% due to the high porosity of 58%. Meanwhile, a great improvement in mechanical property is obtained with a tensile strength of 34.5 MPa, which is about 7 times of POSS-(PMMA46)8/PVDF membrane without support. The interfacial resistance between the corresponding HGPEs and Li electrodes is significantly reduced and as low as 138 Ω. Furthermore, the LiFePO4/HGPEs/Li button cell is assembled and excellent cyclability is shown at 0.1 C and 0.5 C, respectively. The results demonstrate that POSS-(PMMA46)8/PVDF HGPEs could be applied as a promising HGPE candidate for high-performance Li-ion batteries.