Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Reinforcing PVDF-HFP with PEGO-fluidized rigid-rod poly(p-phenylene terephthalamide) (f-PPTA) overcomes the trade-off between mechanical robustness and liquid uptake in microporous polymer electrolytes. The resulting membrane exhibits a finer, more compact porous structure with enhanced porosity and ionic conductivity (1.68 mS cm−1 at 20°C), enabling high charge–discharge capacity (140 mAh g−1) and excellent rate performance in lithium-metal half-cells.

ABSTRACT
Microporous polymer electrolytes (MPEs), which combine solid mechanical stability with liquid-like ion transport capabilities, have attracted considerable attention as an alternative solution to safety concerns in lithium-ion batteries. To address the trade-off between high liquid uptake and mechanical robustness in MPEs, this work employs PEGO-fluidized rigid-rod polymer-poly(p-phenylene terephthalamide) (f-PPTA) to reinforce PVDF-HFP. A series of PVDF-HFP/f-PPTA microporous membranes was prepared via phase inversion. The PEGO ionic segments in f-PPTA contribute to good dispersibility and compatibility with the PVDF-HFP matrix, allowing the rigid-rod PPTA skeleton to fully exert its reinforcement effect. Moreover, due to the strong hydrogen-bonding interactions between the PEGO segments and non-solvent ethylene glycol, the prepared membrane exhibits a finer and more compact microporous structure, with significantly enhanced porosity and liquid absorption capacity. The resulting PVDF-HFP/f-PPTA membrane enables a high ionic conductivity of 1.68 mS cm−1 at 20°C. Li-ion half-cell comprising Li/PVDF-HFP/f-PPTA-4/LiCoO2 delivers high charge–discharge capacity of 140 mAh g−1 and shows satisfactory rate and cycle performance.