A fresh hierarchical-structure gel poly-m-phenyleneisophthalamide nanofiber separator assisted by electronegative nanoclay-filler towards high-performance and advanced-safety lithium-ion battery

In this study, a novel functionalized poly-m-phenyleneisophthalamide (PMIA)-based gel polymer electrolyte (GPE) containing poly(vinylidene fluoridehexafluoropropylene) (PVDF-HFP) and montmorillonite (MMT) nanoclay is synthesized via electrospinning technology. Under the synergistic regulation of PVDF-HFP and nano-MMT, the PMIA-based membrane yields the distinctive hierarchical structure accompanied by extremely high porosity, reduced aperture and well-distributed pore structure, bringing about extraordinary electrolyte uptake. And the as-fabricated GPE renders the engineered functional separator with exceptional thermal stability, robust mechanical strength and uniform lithium-ion flux distribution, which lays a strong foundation for dendrite-proof and advanced-safety batteries. Especially, the well-dispersed MMT-filler within PMIA membrane can provide electronegative atmosphere, stimulating the convenient transmission of lithium ions across separator while preventing the diffusion of negative polysulfide to anode side. Consequently, the lithium-ion cell with the gel PMIA separator obtains a pronounced improvement in cycle stability and rate capability thanks to outstanding ionic conductivity, preferable electrochemical stability and reduced polarization. Meanwhile, the assembled lithium-sulfur battery also delivers preferable cycle performance in virtue of the forceful repulsive force or captured ability of the PMIA-based GPE to dissolved polysulfide species. Therefore, the upgraded designing of hierarchical-structure gel PMIA separator will open up an effective avenue towards high-performance and advanced-safety lithium-ion or lithium-sulfur cells.