Rational Electrode–Electrolyte Design for Long-Life Rechargeable Aqueous Zinc-Ion Batteries

Due to its high theoretical energy density, good safety, and availability, as well as low cost, the rechargeable aqueous zinc-ion battery is considered one of the most promising systems for the next generation of energy storage devices. However, due to the strong electrostatic interaction between Zn2+ and host and the proton/Zn2+ cointercalation in aqueous media, the development of a zinc-ion battery with high capacity and a long lifetime remains an uphill task. In this work, a novel electrode–electrolyte design is employed by using a ZIF/Zn heterostructure as a microporous host matrix and an organic zinc trifluoromethanesulfonate as the constituent of the electrolyte. A zinc-ion battery based on the ZIF/Zn heterostructure anode delivers a specific capacity of 149 mAh g–1 and maintains a retention as high as 80% after 330 cycles at 1 A g–1. The synergistic effect of microstructural ZIF and hydrophobic trifluoromethanesulfonate anions creates a unique electrode–electrolyte interface, which suppresses the formation of dendrites and self-discharge of the Zn anode, resulting in the long cycling stability of the aqueous zinc-ion batteries.