Improvement of surface stability of Zn anode by a cost-effective ErCl3 additive for realizing high-performance aqueous zinc-ion batteries.

ErCl 3 as an electrolyte additive can significantly improve the cycle stability of Zn anode due to the synergistic effect of Er3+ and Cl−, as a result, the Zn||Zn symmetric batteries can stably cycle more than 1100 h. [Display omitted] • ErCl 3 was first introduced as an additive to stabilise the Zn anode. • The ErCl 3 additive could enhance the Zn anode stability by "electrostatic shielding" effect and reducing polarization. • Zn|| Zn-symmetric battery can be stable cycling for 1100 h at 1 mA cm−2 with a fixed capacity of 1 mAh cm−2. • Zn||MnO 2 full battery based on ErCl 3 -added electrolyte illustrates a reversible capacity of 157.1 mAh/g after 500 cycles. Rechargeable aqueous-zinc ion batteries (AZIB) have notable benefits in terms of high safety and low cost. Nevertheless, the challenges, such as dendrite growth, zinc anode corrosion, and hydrogen evolution reaction, impede its practical implementation. Hence, this study proposes the introduction of an economical ErCl 3 electrolyte additive to stabilize the Zn anode surface and address the aforementioned issues. The introduced Er3+ will cover the raised zinc dendrite surface and weaken the "tip effect" on the surface of the zinc anode via the "electrostatic shielding" effect. Simultaneously, the introduced Cl– can reduce the polarization of the zinc anode. Due to the synergistic effect of Er3+ and Cl–, the zinc anode corrosion, dendrite growth and hydrogen evolution have been efficiently inhibited. As a result, the Zn||Zn-symmetric battery using ErCl 3 additive can stably cycle for 1100 h at 1 mA cm−2, 1 mAh cm−2, and exhibit a high average coulomb efficiency (99.2 %). Meanwhile, Zn||MnO 2 full battery based on ErCl 3 -added electrolyte also demonstrates a high reversible capacity of 157.1 mAh/g after 500 cycles. Obviously, the capacity decay rate of the full battery is also improved, only 0.113 % per cycle. This study offers a straightforward and economically efficient method for stabilizing the zinc anode and realizing high-performance AZIBs. [ABSTRACT FROM AUTHOR]