PVDF-HFP/PMMA/TPU-based gel polymer electrolytes composed of conductive Na3Zr2Si2PO12 filler for application in sodium ions batteries

Abstract

Gel polymer electrolytes (GPEs) have attracted abundant attentions due to its higher ion conductivity and better compatibility with electrode than the inorganic solid-state electrolytes and safer than the liquid electrolytes. In this work, sodium conductive Na3Zr2Si2PO12 nanoparticles modified PVDF-HFP/PMMA/TPU-based GPEs are prepared and its application performances in sodium ions batteries (SIBs) are demonstrated. The addition of Na3Zr2Si2PO12 filler decreases the crystallinity of polymer matrix and improves the porosity of GPEs membranes, resulting in the increasing of liquid electrolyte uptake. As a result, the Na3Zr2Si2PO12 filler modified GPEs delivers enhanced ion conductivity as high as 2.83 × 10−3 S cm−1 with a small activation energy of ~0.039 eV and enlarged electrochemical window width of 5.16 V. Application in SIBs, high first discharge capacity of 92.7 mAh·g−1 at 0.5C and promising capacity retention capability (99.2% after 100 cycles) as well as excellent rate performance (83.9 mAh·g−1 at 5C) are recorded for the obtained GPEs. These results suggest that the performances of PVDF-HFP/PMMA/TPU-based GPEs can be enhanced obviously by adding conductive Na3Zr2Si2PO12 filler, promoting the practical application of GPEs in energy storage devices.