Tailoring interfacial Zn2+ coordination via a robust cation conductive film enables high performance zinc metal battery

Aqueous rechargeable zinc metal batteries have sparked enormous attention for large-scale energy storage due to their high capacity, high safety, and low cost. However, limited lifespan and Coulombic efficiency of Zn metal anodes arising from plague deposition and parasitic reactions hinder their further application. Herein, a robust Zn2+ ion-exchanged sulfonated poly (ether ketone) (Zn2+-SPEEK) film is constructed on Zn metal anode. The sulfonate groups (-SO3- ) in the film can provide abundant coordination sites with Zn2+, which can not only manipulate uniform Zn2+ flux, but also reduce Zn2+ desolvation active energy. Consequently, the modified zinc (SPEEK-Zn) anodes effectively inhibit dendrite formation and side reactions, and endow fast Zn2+ transfer kinetics. Symmetric cells with SPEEK-Zn electrodes display ultralong life of over 4000 h at 1 mA cm-2 and 1 mAh cm-2 with a low voltage hysteresis of 50 mV. Even under the condition of high mass loading (~10 mg cm-2) of cathode active material, SPEEK-Zn//VO2 full cells retain a high-capacity retention of 93.1% after continuously running for 140 cycles. This work provides a simple and scalable solution for high performance zinc metal batteries.

Automated summary

Aqueous rechargeable zinc metal batteries have gained significant attention for their high capacity, safety, and cost-effectiveness. However, limited lifespan and Coulombic efficiency of Zn metal anodes have hindered their widespread use. In this study, a Zn2+ ion-exchanged sulfonated poly (ether ketone) film is constructed on the Zn metal anode, which effectively inhibits dendrite formation and side reactions, and improves Zn2+ transfer kinetics.