Advanced Filter Membrane Separator for Aqueous Zinc-Ion Batteries

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aqueous zinc-ion batteries offer low cost and safety but face challenges with zinc dendrites, impacting cycling stability and efficiency.
• Zinc dendrite formation is a critical issue hindering the practical application of these batteries.

Purpose of the Study:

• To introduce a porous water-based filter membrane as a novel separator for aqueous zinc-ion batteries.
• To investigate the dendrite-inhibiting capabilities and performance enhancement offered by the filter membrane separator.

Main Methods:

• Fabrication and characterization of a porous water-based filter membrane separator.
• Testing of symmetrical zinc cells and Zn//NaV3O8·1.5H2O full cells using the filter membrane.
• Electrochemical performance evaluation, including cycling stability, coulombic efficiency, and voltage hysteresis.
• Mechanism investigation into the dendrite suppression properties of the separator.

Main Results:

• The filter membrane separator enabled symmetrical cells to cycle over 2600 hours with low voltage hysteresis (47 mV).
• An aqueous Zn//NaV3O8·1.5H2O cell achieved 83.8% capacity retention after 5000 cycles at 5 A g⁻¹.
• Mechanism studies indicated that uniform pore distribution, not composition, is key to the membrane's dendrite inhibition.

Conclusions:

• Porous filter membranes are effective separators for improving the performance of aqueous zinc-ion batteries.
• The separator's uniform pore structure is crucial for suppressing zinc dendrites and enhancing battery cycling stability.
• This research provides insights into separator design for developing high-performance aqueous zinc-ion batteries.