Volume 9 Issue 2 ( June 2022 )

Separator is an important part of lithium-ion batteries because it acts both as a physical barrier for the electrodes and as an electrolyte reservoir for ion transport. The separator has direct influence on the battery performance. Polyolefins, typical materials used for the fabrication of separator, demonstrate high flexibilities and mechanical strengths but also possess a high ratio of thermal shrinkage and low porosity. The aim of the research is to obtain highly porous and thermally stable separator. Poly(vinylidene fluoride) (PVDF) nanofiber membrane was synthesized via double jet electrospinning method. PVDF was dissolved in variations of solvents, i.e., dimethylformamide-acetone and dimethylformamide-ethanol and added with colloidal SiO₂ at different concentrations of 0 ppm, 1000 ppm, 3000 ppm, and 5000 ppm. The obtained separators exhibited high porosities, high electrolyte uptakes, and thermally stable, resulting in improved performances when assembled in real battery cell systems.

Keywords: Electrospinning, separator, poly(vinylidene fluoride)/SiO₂, nanofiber, lithium-ion battery