Fluidity Rigid-Rod Polymer Reinforced Microporous Polymer Electrolyte With Preeminent Ionic Conductivity and Mechanical Property for Lithium-Ion Rechargeable Batteries

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/LiCoO 2 delivers high charge–discharge capacity of 140 mAh g −1 and shows satisfactory rate and cycle performance.