A rechargeable aqueous dendrite-free zinc ion battery with robust performance enabled by the design of electrolyte additive

Aqueous zinc ion batteries (AZIBs) have attained significant progress in the field owing to their outstanding safety, low cost, and high theoretical capacity. However, several issues, such as dendrite formation and hydrogen evolution reactions, limit the practical application of AZIBs. In this regard, the aforementioned problem of AZIBs is addressed by combining traditional electrolytes with environmentally friendly, non-toxic, and low-cost electrolyte additives. In this work, sodium sulfate and sodium citrate were selected as electrolyte additives for the optimization of AZIBs. It was demonstrated that sodium ions can alter the deposition morphology of Zn²⁺ to prevent dendrite formation, thereby stabilizing the Zn anode. Consequently, the symmetrical cell can cycle stably for 1400 h at a current density of 5 mA cm⁻² and 400 h at 20 mA cm⁻², respectively. This work presents a simple and cost-effective approach to achieve high-performance AZIBs.