- Title : Suppression of side reactions on Zn metal anode by Bi-coated zincophilic three-dimensional Cu host for aqueous Zn-ion batteries

- Authors : Hyeok Jae Lee, Chul Hyun Jun, Chandan Chandru Gudal, Seong Soo Kim, Pil J. Yoo, Jung Kyu Kim, Chan-Hwa Chung*

- Journal : Applied Surface Science
- 10.1016/j.apsusc.2025.163072

Abstract
Rechargeable aqueous Zn-ion batteries have garnered significant interest due to their inherent safety and high power density. However, the long-term cycling performance of the Zn metal anode is impeded by several challenges, including the formation of Zn dendrites, undesirable side-reactions such as the hydrogen evolution reaction (HER), and corrosion. Herein, a three-dimensional (3D) host with a surface coating was employed for the Zn metal anode. A 3D Cu foam was formed using an H2 bubble template, followed by a galvanic displacement reaction with a [BiCl6]3- complex to exploit the chemical properties of Bi, such as its strong affinity for Zn and inertness toward the HER. The resulting 3D Bi-Cu foam synthesized through this method effectively alleviates dendrite growth and inhibits side-reactions, enhancing the lifespan of the battery. In half cell, the 3D Bi-Cu foam exhibited an ultralow nucleation overpotential of 4 mV (vs. Zn2+/Zn) at 1 mA cm