Electrospun High-Thermal-Resistant Inorganic Composite Nonwoven as Lithium-Ion Battery Separator

Abstract EN

Separators are key materials to ensure the safety of lithium-ion batteries and improve their performance.

Currently, commercial lithium-ion battery separators are mainly polyolefin organic diaphragms, but their temperature instability leads to battery short circuit and fire risk.

A flexible SiO2 nanofiber membrane combined with a poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) nanofiber membrane is prepared by an electrospinning method.

The mechanical strength of the SiO2/PVDF-HFP composite nanofiber membrane (SPF) is twice as high as the pure SiO2 nanofiber membrane and at 200°C, there are almost no dimensional changes of the SPF separators.

Compared to commercial polyethylene (PE) separators, SPF shows excellent thermal stability and large-area closed cells at 180°C when used in lithium-ion battery separators.

The porosity of SPF is 89.7%, which is more than twice than that of an ordinary PE separator.

The liquid absorption rate of SPF is much higher than an ordinary PE separator and has reached 483%.

Furthermore, the cycle and rate performance of lithium-ion batteries prepared by SPF has been improved significantly.

These excellent properties, as well as the potential for large-scale production of electrospinning technology, make SPF an ideal choice for high-power battery separators.