Advanced Filter Membrane Separator for Aqueous Zinc‐Ion Batteries

Aqueous zinc-ion batteries with low cost and inherent safety are considered to be the next-generation energy storage device. However, they suffer from poor cycling stability and low coulombic efficiency caused by the serious zinc dendrites during the cycling. In this work, a porous water-based filter membrane is first proposed as separator due to its good toughness and uniform pore distribution. The results demonstrate that the symmetrical cell using a filter membrane can cycle over 2600 h with a low voltage hysteresis of 47 mV. Moreover, an aqueous Zn//NaV3 O8 ·1.5H2 O cell based on the filter membrane is constructed, which demonstrates a high capacity retention of 83.8% after 5000 cycles at 5 A g-1 . The mechanism research results reveal that the excellent dendrites inhibiting the ability of the filter membrane should be attributed to its uniform pore distribution rather than its composition. This work proposes a filter membrane separator and reveals the great influence of separator on the zinc stripping/plating process, which will shed light on the development of high-performance aqueous zinc-ion batteries.