Polyacrylonitrile-based gel polymer electrolyte filled with Prussian blue forhigh-performance lithium polymer batteries

Abstract

Lithium polymer batteries (LPBs) rely on a high ion transport to gain improved cell performance. Thermostable and porous gel polymer electrolytes (GPEs) have attracted much attention due to their excellent properties in electrolyte wettability and ionic conductivity. In this work, iron-nickel-cobalt trimetal Prussian blue analogue (PBA) nanocubes are filled into the electrospun polyacrylonitrile (PAN)-based membranes to generate GPE composites with morphological superiority consisting of fine fibers and interconnected pores. The thus obtained PBA@PAN fibrous membrane showcases good thermal stability, high porosity and electrolyte uptake, as well as a peak ionic conductivity of 2.7 mS/cm with the addition of 10% PBA. Consequently, the assembled lithium iron phosphate (LiFePO4) battery using PBA@PAN-10 as the GPE delivers a high capacity of 152.2 mAh/g at 0.2 C and an ultralow capacity decay of 0.09% per cycle in a long-term cycle life of 350 cycles at 1 C, endorsing its promising applications in LPBs.