Synergistically enhanced roles based on 1D ceramic nanowire and 3D nanostructured polymer frameworks for composite electrolytes

Abstract

Combining high ionic conductivity of inorganic solid electrolyte and favourable interface compatibility of polymer solid electrolyte, organic-inorganic composite electrolyte is more suitable for high-performance solid lithium battery. Herein, the polyacrylonitrile/polyvinylidene difluoride (PAN/PVDF) nanofiber membranes are prepared by electrospinning way, which can provide a strong skeleton support to improve the mechanical strength of composite electrolyte. The complexation between lithium ion and nitrile base of PAN can promote the transport of lithium ions and excellent oxidation resistance matching high-voltage cathode electrode. There are enough intermolecular hydrogen bonds between PVDF and PEO, and the presence of f in PVDF can enhance the interfacial interaction between the fiber membrane, polyethylene oxide (PEO) and lithium metal. Therefore, it can improve the conductivity of lithium ions and effectively inhibit the growth of severe lithium dendrites. Finally, the ionic conductivity of the composite electrolyte formed by introducing the Gd-doped SnO2 nanofibers (GDS NFs) into the PAN/PVDF nanofiber membranes and PEO matrix can reach 2.45 × 10−4 S cm−1 at 30 °C. In addition, the thickness of the composite electrolyte is only 65 μm, which can significantly improve the energy density of the battery. The specific capacity of the battery assembled with the electrolyte can still maintain 134.3 mA h g−1 after 300 cycles at 50 °C and 1C, and the specific capacity retention rate is up to 91.2 %. The NMC batteries also has a high reversible capacity even after 300 cycles. In conclusion, the Gd-doped SnO2 nanofibers and PAN/PVDF nanofiber membranes with excellent properties provide a novel idea for lithium metal batteries (LMBs).