Enhancing Electrospun PVDF-HFP Nanofibres for Lithium-Ion Battery Separators Through the Incorporation of Inorganic Nanoparticles: Physico-Chemical and Electrical Characterisation

This study investigates the physical-chemical and electrochemical performances of innovative separators for Li-ion batteries based on poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) nanofibrous membranes. The nanofibrous mat is produced through the electrospinning process, ensuring high surface to volume (S/V) ratio and allows large-scale production under suitable conditions. The materials investigated in this work aim at overcoming some limitations specific to the commercial separators, for example, mechanical shrinkage and electrolyte uptake. This is achieved by adding nanoparticles of different types, for example, ZrO2, SnO2, SiO2 at different concentrations. Results claim that nanofibrous separators improve the mechanical and thermal stability of the mat without significantly impacting its electrochemical performances. In particular, the addition of 7 wt% of ZrO2 nanoparticles to the nanofibrous separator showed to outperform commercially available solutions (i.e., Celgard) in terms of mechanical and thermal stability exhibiting, also, electrochemical performances.