Gel electrolytes based on polyacrylonitrile/thermoplastic polyurethane/polystyrene for lithium-ion batteries

Using an electrospinning method, high-performance gel polymer electrolytes (GPEs) comprising polyacrylonitrile/thermoplastic polyurethane/polystyrene (PAN/TPU/PS) were prepared. Then, these electrolytes were used to assemble button cells. The GPEs exhibited a maximum ionic conductivity of 3.9 × 10−3 S cm−1 at room temperature, with an electrochemical stability of 5.8 V. In addition, a Li/GPE/LiFePO4 cell showed first charge and discharge capacities of 161.70 mAh g−1 and 161.44 mAh g−1, respectively, at a 0.1 C rate and a stable cycle performance (the capacity retention was nearly 94% after 50 cycles) with high coulombic efficiency. Additionally, the SEM images showed that the PAN/TPU/PS was not composed of beaded-fibres in a fibrous membrane but was composed of fibres that were slim with a uniform size distribution. The uptake behaviour and porosity of the PAN/TPU/PS fibres showed the best performance and superior physical properties of the tested samples (the elongation at break of the film was 115.15%, and the tensile strength was 9.86 MPa). Considering these results, the PAN/TPU/PS blend/composite film has broad prospects for use in lithium-ion batteries.