造纸法制备CNF/PMIA/PPTA锂电池隔膜OA北大核心CSTPCD

CNF/PMIA/PPTA lithium-ion battery separators were prepared by wet forming of paper-making method using water-soluble poly-imide(PI)as reinforcing agent,and mixing cellulose nanofiber(CNF)and poly(ethylene oxide)-modified poly(aramid fiber)(PMIA/PP-TA)suspension.After characterization and analysis of separator performance,the effects of dispersion and stability of CNF and PMIA/PPTA suspensions and the mass fraction of each component on the mechanical and electrochemical properties of the separator were investigated.The results showed that the composition and dosage for the optimum properties of separator was:CNF(mass fraction of 0.5%,relative to the mixed total pulp mass,the same below),PMIA/PPTA fibers(mass fraction of 0.5%,mass ratio of 5:5),diatomaceous earth(mass fraction of 0.05%);and PI aqueous solution was sprayed(spraying quantity of 1.5%,relative to the absolate dry mass of the separator).At this time,the tensile strength of the lithium-ion battery separator was 23.74 MPa,the elongation at break was 3.41%,the liquid absorption,liq-uid retention,and porosity were 237.16%,152.88%,and 69.34%,respectively,and the thermal shrinkage was only 0.31%,with an ionic conductivity of up to 1.041 mS/cm;the first discharge capacity of the lithium-ion battery assembled by separator was 158.2 mAh/g.The CNF/PMIA/PPTA lithium-ion battery separator not only had excellent thermal stability,but also higher ionic conductivity,wider electrochemical sta-bilization window,excellent multiplicity and cycling performance,which met the technical safety requirements of lithium-ion battery separator.