Electrospun Trilayer Polymeric Membranes as Separator for Lithium–ion Batteries

Poly(vinylidene fluoride- hexafluoropropylene) (PVdF-HFP)/poly (vinyl chloride) (PVC)/(PVdF-HFP) based- trilayer porous polymeric membrane (PM) was prepared by electrospinning for lithium batteries. The formation of beads was significantly reduced by increasing the concentration and by reducing the surface tension of the polymer solutions. Although, single layer PVdF-HFP membrane exhibited high porosity and uptake of electrolyte, its mechanical integrity was found to be poor (not free-standing). On the other hand, electrospinning of PVC over PVdF-HFP enhanced the mechanical integrity of the membrane. The prepared membranes were subjected to SEM, ionic conductivity, electrolyte uptake and shrinkage analyses. A 2032-type coin cell composed of Li/PM/LiFePO4 has been assembled and its cycling profile was examined at different C-rates. The (PVdF-HFP)/PVC/(PVdF-HFP) trilayer membrane can be a strong contender for lithium battery applications.

Cross-sectional SEM image of PVdF-HFP/PVC/PVdF-HFP trilayer membrane.Figure optionsDownload as PowerPoint slide