PVDF/halloysite nanocomposite‐based non‐wovens as gel polymer electrolyte for high safety lithium ion battery

Abstract

Gel polymer electrolyte (GPE) based on electrospun poly(vinylidene fluoride) (PVDF)/halloysite nanotube (HNT) nanocomposite non‐wovens was synthesized and its suitability as a separator in lithium‐ion battery (LIB) was explored. In this study, HNT played a key role in reducing the average diameter of the electrospun fibers and uplifted the porosity of the non‐wovens thereby improving their electrolyte uptake. Due to a reduction in crystallinity and increased % porosity of the PVDF/HNT non‐wovens, the ionic conductivity (1.77 mScm−1) and ionic transport across the separator were improved. Moreover, this GPE separator exhibited high tensile and puncture strength with negligible thermal shrinkage and a higher melting temperature compared with a commercially available separator, which is vital from the safety perspective. The cycling performance of Li/GPE/LiCoO2 cell was evaluated and it exhibited a high capacity of 138.01 mAhg−1 with 97% coulombic efficiency for the initial cycle. The cell was stable and retained its high performance with little loss in capacity even after repeated charge–discharge cycles. Such a combination of high ionic conductivity, tensile strength with low thermal shrinkage is seen to be very rare in polymer‐based separators. It is noteworthy that this novel GPE outperformed the commercial separator also in the cycle performance. POLYM. COMPOS., 40:2320–2334, 2019. © 2018 Society of Plastics Engineers