Understanding the Electrical Mechanisms in Aqueous Zinc Metal Batteries: From Electrostatic Interactions to Electric Field Regulation

Abstract

Aqueous Zn metal batteries are considered as competitive candidates for next-generation energy storage systems due to their excellent safety, low cost, and environmental friendliness. However, the inevitable dendrite growth, severe hydrogen evolution, surface passivation, and sluggish reaction kinetics of Zn metal anodes hinder the practical application of Zn metal batteries. Detailed summaries and prospects have been reported focusing on the research progress and challenges of Zn metal anodes, including electrolyte engineering, electrode structure design, and surface modification. However, the essential electrical mechanisms that significantly influence Zn2+ ions migration and deposition behaviors have not been reviewed yet. Herein, in this review, the regulation mechanisms of electrical-related electrostatic repulsive/attractive interactions on Zn2+ ions migration, desolvation, and deposition behaviors are systematically discussed. Meanwhile, electric field regulation strategies to promote the Zn2+ ions diffusion and uniform Zn deposition are comprehensively reviewed, including enhancing and homogenizing electric field intensity inside the batteries and adding external magnetic/pressure/thermal field to couple with the electric field. Finally, future perspectives on the research directions of the electrical-related strategies for building better Zn metal batteries in practical applications are offered.