Design on modified glass fiber separator by ball-milled tin fluoride particles for Zn metal anodes with high reversibility

Abstract Aqueous zinc ion batteries (AZIBs) are considered as a promising alternative to lithium-ion batteries for grid-scale energy storage due to superior energy density, high safety, eco-friendliness and low cost. However, uncontrollable zinc dendrite growth and parasitic side reactions seriously compromise the performance of zinc metal anodes, thereby hindering practical development of AZIBs. In this work, zinc metal anodes are reinforced via a SnF2-modified glass fiber separator (denoted as SnF2@GF). Due to excellent ionic conductivity and zincophilicity of SnF2, the SnF2@GF separator can effectively homogenize Zn2+ flux to inhibit the growth of zinc dendrite and the formation of Zn4SO4(OH)6·5H2O byproducts. As a result, the Zn||Zn symmetric cell exhibits highly reversible plating/stripping behaviors for 1400 h at 1 mA cm− 2, and even at 5 mA cm− 2, it can operate stably for more than 1000 h. In addition, the assembled Zn||MnO2 full cells demonstrate a high capacity retention of 80% after 200 cycles at 1 A g− 1. Our results provide a facile and low-cost method of enhancing reversibility of zinc metal anodes for high-performance AZIBs.