Investigating effect of Graphene Oxide on the morphology and electrochemical properties of Polymer Electrolyte based on Poly(vinylidenefluoride) for lithium-ion batteries

Abstract

Solid polymer electrolytes (SPEs) show good structural flexibility and safety to meet the requirements of lithium-ion battery applications. Poly(vinylidene fluoride) (PVDF) is a semi-crystalline polymer which due to its desirable has been considered as promising candidate for fabrication of polymer electrolytes in Li-ion batteries. PEs usually have a low ionic conductivity at room temperature. In this study, in order to eliminate this problem and improve the ionic conductivity improving additives of lithium-ion battery graphene oxide (GO) were investigated. Then, the additive amount was optimized using the Morphology, Tensile strength, ionic conductivity, Li+ ion transference number and electrochemical stability, which determined the optimal amount of (GO). SEM images were shown that SPEs containing GO have more porosity in comparison with GPE without GO. By adding 0.004 wt% GO, the ionic conductivity of the PVDF/GO polymer electrolyte was increased significantly to 3.60 mS cm-1 for the composite and the transference number of Li+ ion was also increased to 0.74. The electrochemical stability of 4.6 V was achieved. The results show that GO not only increased the ionic conductivity of composite membrane but also improved the physical properties of the polymer electrolyte. This study shows that the PVDF/GO polymer electrolyte can be considered as a promising SPE for lithium ion batteries.

Keywords

• lithium-ion battery
• polymer electrolytes
• poly (vinylidenefluoride)
• graphene oxide
• casting solution