Synthesis of PVDF/SiO2 nanofiber membrane using electrospinning method as Li-ion battery separator
Hendri Widiyandari (a*), Oki Ade Putra (a), Agus Purwanto (b), Zainal Abidin (c)
a) Department of Physics, Sebelas Maret University, Surakarta, Indonesia
b) Departement of Chemical Engineering, Sebelas Maret University, Surakarta, Indonesia
c) Departement of Physics, Diponegoro University, Semarang, Indonesia
Abstract
The PVDF/SiO2 (Polyvinilidene fluoride/Silica) nanofiber membrane were prepared by electrospinning method. The SiO2 colloid nanoparticle concentration was varied at 500, 1000 and 3000 ppm. The PVDF is a material that developed in the manufacture of separators. The PVDF has a higher polarity, melting point and electrolyte uptake than the PP material commercial separators. The effect of the SiO2 nanoparticle addition to the PVDF nanofiber membrane to improve membrane characteristics which include porosity, high temperature stability mechanical, mechanical strength and the stability of battery capacity were systematically investigated. The parameter of electrospinning method with 15 kV voltage, flow rate 1,5 ml / hour, needle distance with collector 17 cm and time 1 hour. The immersion of PVDF membrane in colloid SiO2 nanoparticles was carried out for 1 hour. The shape and fiber size were analyzed by SEM (Scanning Electron Microscope). The SEM image shows the PVDF nanofiber membrane which has beaded fibers with an average fiber size is ~ 656 nm. The nanoparticel SiO2 formed double layer on the PVDF membrane. The porosity effect of PVDF without SiO2 and PVDF/SiO2 3000 ppm is 57% and 70%, respectively. The effect of addition SiO2 to mechanical strength were increased until 2.7 MPa and the membrane were stable at 150 C for 30 minutes. The PVDF membrane has a higher specific capacity than the PP membrane that is 104.6 mAh/g. The addition of SiO2 nanoparticles increased the PVDF membrane capacity stability by the decrease of specific capacity of 42.7 mAh/g for PVDF membrane to 18.7 mAh/g with the addition of SiO2 3000 ppm nanoparticles.
Keywords: PVDF/SiO2; Separator; Membrane; Nanofiber; Electrospinning; Li-ion Battery
Topic: Functional Materials