Inhibiting Vertical Zinc Growth Using Low-Cost Composite Membranes

Vertical growth of Zn crystals is widely recognized as a primary factor responsible for the premature failure of aqueous Zn batteries. These vertically aligned sharp-tipped Zn plates can easily pierce the separator, propagating toward the cathode side, and short-circuit the cell. While inhibition of this phenomenon may be achieved by electrolyte engineering or manipulation of the anode’s interface, we propose herein an effective suppression of vertical Zn growth by replacing the conventional separators with highly affordable commercially available printing paper. Based on electrochemical and structural studies followed by small punch measurements, we found that these papers comprise nanometric rigid ceramic particles that act as a physical barrier for the growth of Zn plates, preventing their penetration through the paper-based separator. As a result, the examined cells demonstrate excellent long-term performance, surpassing cells that utilize commonly used separators, which typically fail after only several to tens of cycles. These findings offer a highly effective strategy for enhancing the cyclability of Zn-based batteries.