Electrochemical characteristics of electrospun poly(methyl methacrylate)/polyvinyl chloride as gel polymer electrolytes for lithium ion battery

Various electrospun poly(methyl methacrylate)/polyvinyl chloride (PMMA/PVC) blend nonwoven membranes were prepared by electrospinning of the blend solutions containing PMMA and PVC in N,N-dimethylformamide (DMF). The electrospun PMMA/PVC had fully interconnected pore structure with high porosity and large specific surface area capable of high uptake of organic liquid electrolyte as gel polymer electrolytes (GPEs). The electrospun PMMA/PVC-based GPEs showed superior electrochemical properties than PVC-based GPE. Among PMMA/PVC-based GPEs, the 10PMMA/PVC-based GPE comprising 10 wt.% PMMA and 90 wt.% PVC represents the highest ionic conductivity as 7.8 × 10−3 S cm−1 and the lowest interfacial resistance as 31.49 Ω with sufficient electrochemical stability of up to 4.7 V. The LiCoO2/GPE/graphite cell using 10PMMA/PVC-based GPE retained the discharge capacity of 140 mAh g−1 after 100 cycles at 0.5 C without reducing discharge capacity, while PVC-based GPE showed continuous fading by 110 mAh g−1. Also, the cell using 10PMMA/PVC-based GPE showed the excellent electrochemical performance caused by the formation of interconnected porous structure and gel state in fibers even at high C-rate (1, 2, 5 C).

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► Fibrous PMMA/PVC-based GPEs were prepared by immersing the PMMA/PVC blend nonwoven membranes into the liquid electrolyte.
► Electrochemical stability of the GPEs improves with increasing PMMA content.
► 10PMMA/PVC-based GPE shows the excellent specific capacity as well as outstanding cycle retention.
► Cyclic stability of 10PMMA/PVC-based GPE is excellent even at high C-rate (5 C) without cycling fading.