Controlling Horizontal Growth of Zinc Platelet by OP-10 Additive for Dendrite-Free Aqueous Zinc-Ion Batteries

Abstract

Rechargeable zinc-ion batteries based on aqueous electrolytes are advantageous in terms of being environmentally friendly, safe and low cost. However, the problems of zinc dendrites and irreversible by-products on the Zn metal surface during the charging and discharging processes limit its practical application. Herein, octenyl phenol polyoxyethylene ether-10 (OP-10) with an oxygen-rich chain is used as an electrolyte additive to significantly improve the stability of the Zn anode. With an ultralow addition content of about 0.1 wt %, the OP-10 can not only promote the uniform deposition of Zn²⁺ by adjusting the growth orientation of the (002) crystal plane of Zn but also alleviate side-reaction on the metal surface. Thus, the Zn//Zn cell is stable for more than 800 hours at 1 mA cm⁻², and the Zn//Cu cell has a Coulombic efficiency of up to 99.80 %. Further, the Zn//V₂O₅ ⋅ 1.6H₂O battery exhibits outstanding cycle stability over 1000 cycles (maintain 92.12 % at 10 C), which is much superior to pure ZnSO₄ electrolyte. OP-10 not only reduces cost but also increases battery energy density, which is more in line with the modification idea of “small dose and large effect” of additives.