Microporous polymer films as separators for lithium-ion batteries

New microporous polyethylene, polypropylene and polyvinylidene fluoride films have been elaborated as separators for lithium-ion batteries. The samples were obtained by a technique based on polymer melt extrusion. Investigation of the batteries in the mode of charge-discharge cycles was carried out. It is shown that these porous materials match or exceed performance characteristics of commercial separators “Celgard 2400”. It was found out that the usage of polyethylene separators allows preventing emergency situations which may be induced by an uncontrollable temperature increase during the battery operation.