Preparation of high temperature enhanced dimensional stability membranes for lithium-ion battery separator
Volume Title: 1
1Research Institute of Petroleum Industry (RIPI), Tehran, Iran
2Department of Chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
3: Research Center for Membrane Separation Processes, Faculty of Chemical Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran, Iran
4Membrane Research Center, Faculty of Petroleum and Chemical Engineering, Razi University, Kermanshah, Iran
5Department of Chemistry, Amirkabir University of Technology, Tehran, Iran
PVDF membranes were prepared by non-solvent induced phase inversion method with enhanced dimensional stability at high temperatures for application as lithium ion battery's (LIBs) separator. Effects of the polymer molecular weight (1.100.000, 352.000 gr/mol), solvent type (NMP, DMF) and coagulation bath temperature (CBT, 20, 30 °C) were studied. The results showed that the separators prepared by high molecular weight polymer, NMP as solvent and coagulation bath temperature of 20 °C have higher dimensional stability at 165 °C. This best prepared separator's (S4) thermal shrinkage was the lowest (27 %) among all the prepared separators. Battery performance was determined by assembling Li/LiFePO4 half - cell (2032 type coin). The cycle performance of cell assembled by enhanced PVDF membrane were higher ( 97.8 % reduction after 25 cycles) compared with that of assembled by commercial PP separator (96.4 % after 25 cylces).