Metal anode instabilities of aqueous batteries, including dendrite growth, metal corrosion, and hetero-ions interference, occurring at the electrolyte/electrode interface, are among the most critical issues hindering their widespread use in energy storage. Herein, a universal strategy is proposed to overcome the anode instability issues by rationally designing alloyed materials, using Zn-M alloys as model systems (M = Mn and beyond), due to the modified diffusion barrier of Zn on the alloy surface. An in-situ visualization coupled with finite element analysis is for the first time utilized to observe the dynamic processes of plating and stripping in aqueous batteries. The in-situ visualization reveals that the metal Zn preferentially grows inside and around the three-dimensional (3D) structured Zn-M alloy. Density functional theory (DFT) simulation reveals that a stronger interaction between the deposited Zn and Zn-M alloys with a low activation barrier for Zn diffusion resulting in the smooth nucleation and growth of Zn. As a proof-of-concept, the novel Zn-M alloy anodes achieved unprecedented stability with nearly 100% Coulombic efficiency over thousands of cycles even in seawater-based aqueous electrolytes under an aggressive current density of 80 mA cm-2. The proposed design strategy and the first in-situ visualization protocol for 3D alloyed anode set up a new milestone in developing durable electrodes for aqueous batteries and beyond.
Revised: February 2, 2021 |
Published: January 11, 2021