Novel configuration of heat-resistant gel polymer electrolyte with electrospun poly (vinylidene fluoride-co-hexafluoropropylene) and poly-m-phenyleneisophthalamide composite separator for high-safety lithium-ion battery

摘要

In this work, a novel nanofiber composite membrane constituting poly (vinylidene fluoride-co-hexaflu oropropylene)/poly-m-phenyleneiso-phthalamide (PVDF-HFP/PMIA) was successfully fabricated through one-step electrospinning technique. The PVDF-HFP/PMIA nanofibers possessed low average diameter and uniform diameter distribution, which were able to be acted as matrix for gel polymer electrolyte. Significantly, the presence of PVDF-HFP endowed PMIA membrane with considerable high electrolyte uptake and porosity, eminent mechanical strength and remarkable thermal shrinkage resistance. Compared with pure PMIA and polyethylene separators, the PVDF-HFP/PMIA separator obtained higher ionic conductivity, lower interfacial resistance and more stable electrochemical window. The Li/LiCoO2 battery with the prepared separator reflected admirable cycle stability with outstanding first discharge capacity up to 153.8 mAh g(-1) at 0.5C rate and superior capacity retention of 88.75% after 100 cycles. (C) 2018 Elsevier B.V. All rights reserved.