LAUSR

Abstract Dendrite formation and corrosion are two major problems occurring on the zinc electrode of the rechargeable hybrid aqueous battery (ReHAB). In this work, we have designed a gel electrolyte containing fumed silica (FS) as the gelling agent and Pb 2+ as the dendrite suppressor and also the corrosion inhibitor in aqueous liquid media. Both Pb 2+ and fumed silica can inhibit dendrite formation, evidenced by chronoamperometry results and ex-situ scanning electron microscopy images. Furthermore, linear polarization results reveal that corrosion current density on the Zn anode when in contact with the PbSO 4 doped 5%FS gel electrolyte is 20% smaller than that of the Zn when in contact with the reference aqueous electrolyte. The ReHAB using the Pb 2+ containing gel electrolyte exhibits higher cyclability (75% capacity retention after 300 cycles at 1 C rate) than the ReHAB using the reference aqueous electrolyte (60% capacity retention at the same condition). Self-discharge is massively reduced, represented by an 18% smaller loss of open-circuit voltage after monitoring for 24 h. Float charge current density is reduced significantly up to 35% after 24-h of constant charging the batteries at 2.1 V vs. Zn 2+ /Zn. The results suggest that battery performance improves when both corrosion current density and dendrite formation are suppressed.