Performance research on modification of polypropylene separator for lithium ion batteries by zeolite/polyvinyl alcohol coating
To improve the electrolyte wettability and thermal dimensional stability of the commercial polypropylene(PP)separators for lithium ion batteries,zeolite/polyvinyl alcohol coated PP separators have been prepared by dip-coating method.The morphology,porosity,hydrophilicity,electrolyte uptake,thermal stability and electrochemical properties of the modified PP separators were studied by scanning electron microscopy(SEM),battery test system and electrochemical workstation.Compared with the commercial PP separator,it showed that the porosity increased from 38.4％to 41.2％,and the electrolyte uptake increased from 108.4％to 181.1％,but the heat shrinkage reduced from 58％to 23％at 170 ℃ after modification.Compared with commercial PP separator,the electrochemical performance and stability of the modified PP separator are also improved.The interfacial impedance was reduced from 88 Ω to 61 Ω,and the ionic conductivity increased from 0.58 mS/cm to 0.75 mS/cm.The results show that zeolite/polyvinyl alcohol coating is an effective way to improve the electrochemical properties and thermal stability of PP separator,and can improve the cyclicality and safety of lithium batteries.
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维普
