Preparation and characterization of porous PVdF-HFP/graphene oxide composite membranes by solution casting technique

Poly(vinylidenefluroide-co-hexafluoropropylene) (PVdF-HFP) is used as a polymer electrolyte for energy storage devices like batteries, supercapacitors, and electric double layer capacitors (EDLC's) due to its high mechanical stability, thermal stability and ionic conductivity. Plasticized lithium ion conducting PVdF-HFP membrane was prepared with ethylene carbonate (EC) and LiClO4 as plasticizer and salt, respectively via simple solution casting technique. Membranes were made of PVdF-HFP (50 wt%), EC (35 wt%), lithium perchlorate (LiClO4) (15 wt%) with various wt% of graphene oxide (GO) (0.1, 0.2, 0.3, 0.4 wt%) . The structural analysis of the membrane was made through XRD and FTIR studies. The morphological aspects were analyzed through Scanning Electron Microscopy. The membrane comprising 0.1 wt% of GO was optimized to have good ionic conductivity of 1.58 x 10(-4) S/cm, as explored by AC impedance analysis. The role of GO on the porous nature of the membranes and its effect on the electrical property of the membrane, its electrochemical stability and the electrochemical performance of the EDLC are explained. The changes in electrical properties of the membranes after the pore filling with electrolyte and hence the changes in electrochemical performances were explored.