Porous rigid-flexible polymer membrane interface towards high-rate and stable zinc-ion battery

Although aqueous zinc-ion batteries have been widely investigated as promising energy storage devices, the side effect of irreversible dendritic growth on cycling stability still exists to impede their practical applications. In this work, the porous rigid-flexible polymer composite membrane is successfully constructed by coupling rigid polymers of intrinsic microporosity (PIMs) with highly flexible polyvinylidene fluoride (PVDF). The afforded PVDF-PIM (P-PIM) membranes present various morphologies according to the different rigidity of PIMs. As a protective layer of zinc (Zn) anode, the PVDF-PIM-1 (P-PIM-1) membrane with a unique “sea-islands” morphology exhibits excellent electrochemical performances. The rigid island-region consists mainly of porous PIM-1, which is enriched with Zn2+ transport channels to enable fast reaction kinetics, and the flexible sea-region has a good dynamic adaptive capability. After coating P-PIM-1 membrane on Zn anode, the symmetric battery could retain 99.6% Coulombic efficiency (CE) after 500 plating/stripping cycles at a current density of 4 mA cm−2. The assembling [email protected]//NH4V4O10 full battery delivers an ultra-long life of 14500 cycles and exceptional capacity retention of 113 mAh g−1 at 10 A g−1. The porous rigid-flexible interface provides a new approach for stable Zn anode.