Lithium-ion Battery Separator Of EVOH-SO₃Li Non-woven Membrane

In the whole world of resources are depleted and the global climate isdeteriorating environment, the development of low-carbon life has become thefocus of attention.The lithium-ion battery as an important source of power, moreand more favored by the national researchers. With its compact size, highspecific energy, long cycle life, no memory effect, safe and reliable, and fastcharge and discharge, etc, used in more fields.Divide as an important part of thelithium-ion battery, its performance has research value.A polymer of poly （ethylene-co-vinyl alcohol） end-capped with sodiumsulfonate （EVOH-SO₃Na） is synthesized with poly （ethylene-co-vinyl alcohol）（EVOH） and1,3-propane sultone, a polymer of EVOH-SO₃Li is obtained byion-enchange, and measured the degree of sulfonation, ion-exchange capability.Which structures were identified by FT-IR, determine the synthesis conditionsand the ratio of raw materials. The EVOH-SO₃Li non-woven membrane isprepared by electrospinning technique, in the spinning solution concentration of18%, spinning voltage of17.5V, and the spinneret plate spacing10cm, rate2ml/h, the best electrical properties of the EVOH-SO₃Li non-woven membranes.The EVOH-SO₃Li non-woven membranes were studied by FT-IR, scanningelectron microscopy （SEM） and electrochemical integrated analyzer. The testresults showed that the electrospinning process parameter impacts on themorphology of EVOH-SO₃Li non-woven membrane, the spinning voltage and theconcentration of spinning solution on the fiber diameter and arranged in a moreobvious impact. The electrochemical tests show that the electrochemical windowof EVOH-SO₃Li non-woven membrane is stability, the stability limit voltagereaches6.0V, the thickness of non-woven membrane is25μm, the ionicconductivity of1.22×10^-4s/cm, the results are ideal, experimental results andcommercial divide of the proceeds of lithium ion transference number is closer（0.818）.The results of our study indicated that the EVOH-SO₃Li non-wovenmembranes have value with lithium-ion battery separator applications. This ionpolymer non-woven membrane meets the requrirements of a battery separator,this point is proved by the physical and electrochemical properties of test results,but applications should continue to improve its mechanical properties.