Magnetohydrodynamics and Magnetic Interface Enable Stable Zinc Anode

Abstract

Abstract Aqueous zinc ion batteries have attracted enormous attention for their application in large‐scale energy storage. However, severe Zn dendrite is generated during cycling due to the poor deposition/diffusion kinetics and inhomogeneous Zn 2+ diffusion. Herein, a new approach combining magnetohydrodynamics (MHD) and magnetization effect is proposed to understand the Zn 2+ deposition/dissolution mechanism under an external magnetic field, in which zeolite‐anchored paramagnetic Co 3 O 4 is constructed on Zn anode|electrolyte interface. Co 3 O 4 is magnetized with the generation of abundant MHD micro‐regions (Micro‐MHD) by an external magnetic field, which enables the stability of Zn anode. The magnetized Co 3 O 4 effectively enhances the charge transfer on Zn anode|electrolyte interface, improving Zn 2+ deposition/diffusion kinetics. Affected by Micro‐MHD, the electrolyte is stirred by spiraling Zn 2+ . This feature ensures the rapid and dynamic interfacial diffusion to eliminate concentration gradient. The obtained results highlight the uniform Zn 2+ diffusion driven by Micro‐MHD for achieving stable cycling over 1200 h at 5 mA cm −2 , while maintaining stable Zn 2+ plating/stripping process at a high depth of discharge (DOD = 57%). The Zn||V 2 O 5 ·H 2 O pouch cell exhibits a high capacity and capacity retention for 500 cycles at 1 A g −1 . This work provides a new insight for realizing stable Zn anode.