Gel Polymer Electrolyte Based on Poly(vinylidene fluoride)/Thermoplastic Polyurethane/Polyacrylonitrile by the Electrospinning Technique

Poly(vinylidene fluoride) (PVdF), thermoplastic polyurethane (TPU), and polyacrylonitrile (PAN) are blended in different ratios by the electrospinning technique. The corresponding composite gel polymer electrolytes (GPEs) are obtained after activating the electrospun membranes in 1.0 mol dm –3 LiPF 6 in ethylene carbonate/dimethyl carbonate (EC/DMC). Their morphology and performance are systematically investigated by scanning electron microscopy (SEM), thermal analysis (TGA), charge–discharge tests, and so on. The gel polymer electrolyte (GPE) based on PVdF/TPU/PAN (2/2/1, wt %) exhibits a high ionic conductivity of 6.91 × 10 –3 S cm –1, and its electrochemical stability window reaches up to 5.7 V. Furthermore, the Li/GPE/LiFePO 4 cell shows a first discharge capacity of 167.52 mAh g –1 at 0.1 C rate at 25 °C. The film also exhibits a high tensile strength (10.3 ± 0.2 MPa) and elongation (102.5 ± 0.2%). It is observed that the PVdF/TPU/PAN (2/2/1, wt %) based GPE is perfectly suitable for high-performance lithium ion rechargeable batteries.