Dual-Ion Metal Electrolyte Additives Regulate the Interfacial Reaction of Zinc Anodes

In this work, a low-cost rare-earth metal salt, ammonium cerium(IV) sulfate (ACS), has been selected as a multifunctional electrolyte additive. During cycling, the introduction of tetravalent Ce 4+ ions plays a crucial role. It forms a dynamic shielding layer on the anode’s zinc protrusions, improving energy storage performance by regulating and inhibiting issues. This layer effectively guides the homogeneous deposition of Zn 2+ ions and acts as a safeguard to prevent excessive zinc dendrite formation. Additionally, the incorporation of NH 4 + dynamically regulates the electrolyte’s pH during cycling, reducing OH – content and suppressing side reactions and the hydrogen evolution reaction. When utilizing this electrolyte, the Zn//Zn cell has a long cycling life of 2000 h under the conditions of 1 mA cm –2 and 1 mAh cm –2 . The Zn//Cu asymmetric cell attains a mean CE exceeding 99.7% after 350 cycles under the conditions of 1 mA cm –2 and 1 mAh cm –2 . More importantly, Zn-ion capacitors assembled with this electrolyte demonstrate extraordinary cycling stability, with over 34,000 cycles under a condition of 1 A g –1 .