Electrospun PVDF-HFP/MXene Membrane to Suppress Dendrite Growth for Safer Lithium Metal Batteries

The uncontrolled growth of lithium dendrites on the anode and the inadequate thermal stability of the present polyolefin separators diminish the electrochemical performance and safety of lithium batteries (LBs). This study involved the fabrication and comprehensive characterization of electrospun PVDF-HFP/MXene nanofiber membranes, focusing on the shape, crystallinity, porosity, electrolyte absorption, and electrochemical characteristics. The prepared membrane functions in a saturated liquid electrolyte environment (1 M LiPF6 in EC/DMC, 1:1 v/v), where its porous architecture and surface chemistry facilitate elevated electrolyte affinity (480%) and ionic conductivity (2.02 mS cm–1). In symmetric Li/Li cells, the PVDF-HFP/MXene separator exhibits stable cycling with diminished polarization for 350 h at a high current density of 1.5 mA cm–2, and postmortem SEM surface and cross-sectional analyses validate more uniform lithium deposition and inhibited dendrite growth. In complete LiFePO4/Li cells, the membrane demonstrates exceptional cycling stability after 300 cycles and a superior rate capability. The findings underscore the promise of PVDF-HFP/MXene membranes as secure and high-performance separators for lithium batteries.