Stabilizing zinc anodes by a solvation sheath modification with toluenesulfonate additive

As an advanced electrochemical energy storage device, aqueous zinc-ion batteries offer high theoretical capacity and energy density, employing water-based electrolytes to reduce fire and explosion risks. However, zinc tends to form dendrites during charge-discharge processes, leading to reduced electrode surface area and shortened cycling lifespan. In this study, we propose the use of a commonly used and cost-effective additive, sodium ptoluenesulfonate (OTM), to stabilize zinc anodes. Experimental and theoretical simulations demonstrate that OTM can enter the solvation sheath of Zn2+, reduce the activity of nearby H2O molecules, facilitate uniform Zn2+ deposition, and suppress zinc dendrite formation. Therefore, Zn//Zn symmetric batteries utilizing ZnSO4 (ZSO) electrolytes containing OTM achieved outstanding long-term performance exceeding 1700 h at 1 mA cm- 2 , significantly surpassing those employing ZSO electrolytes. Additionally, Zn//VO2 full batteries with OTM additives exhibited enhanced cycling stability and an initial discharge capacity of 180 mAh g- 1 at 3 A g- 1 , demonstrating its superior application potential.