Research progress on self-discharge mechanisms and mitigation strategies for aqueous zinc-ion batteries

Abstract

The growing demand for large-scale electrochemical energy storage has driven the development of battery systems with high safety, low cost, and high energy density. In this context, aqueous zinc-ion batteries (AZIBs) present significant potential due to their inherent safety, resource abundance and environmental friendliness. However, severe self-discharge behavior leads to rapid capacity decay and voltage drops during storage, thereby restricting their large-scale application. This review systematically summarizes the mechanisms and suppression strategies for self-discharge in AZIBs. It focuses on the fundamental inducements and detrimental effects of self-discharge. Furthermore, this review provides comprehensive research advances for enhancing the anti-self-discharge performance through various strategies, including anode interface engineering, cathode structural regulation, functional binder design, biomimetic separator modification, and electrolyte optimization. Finally, this review points out the current deficiencies in systematic synergetic design. It also provides an outlook on the future development of low-self-discharge zinc batteries through multi-scale regulation and the integration of smart materials.