Ultraviolet-thermal coupling cross-linked fabricate polymer/ceramic composite solid electrolyte for room temperature quasi solid state lithium ion batteries

Polymer-based electrolyte, as a key component of lithium ion solid state battery, has good adaptability to lithium metal anode, and has received extensive attention in recent years. However, the low conductivity, limited thermal stability and poor mechanical strength of polymer-based solid electrolytes restricting its commercial application. Herein, We reveal experimentally that the Polyvinylidene fluoride-co-hexafluoropropylene (PVDFHFP)/Li1.3Al0.3Ti1.7(PO4)3 (LATP) composite solid electrolyte can be prepared by means of ultraviolet and thermal coupling curing (UV-TC) process, and the electrolyte film has better electrochemical performance than that prepared by means of thermal curing (TC) process. Therefore, the carefully designed electrolyte film is efficiently prepared by UV-TC curing process to improve the specific capacity (152.34 mAhg- 1), the rate performance (89.04 mAhg-1 at 1 C) and good cycle performance (92.3 % retention rate in 100 cycles at 0.1 C) at room temperature for Li||PVDF-HFP/LATP||LFP solid state battery. The ionic conductivity of the solid electrolyte film prepared by the UV-TC method (4.3 x 10-4 S cm-1) is more encouraging than that of the TC method (9.2 x 10-5 S cm-1). This work shows that the polymer/ceramic composite solid electrolyte films (CSEs) prepared by simple and efficient UV-TC method has great prospects in realizing high energy density and high safety room temperature quasi solid state lithium ion batteries.