Zn‐Rejuvenated and SEI‐Regulated Additive in Zinc Metal Battery via the Iodine Post‐Functionalized Zeolitic Imidazolate Framework‐90

Abstract

AbstractDue to the high abundance of their components, low cost, and high safety, zinc‐based batteries open up new vistas for large‐scale energy storage. However, their stability, lifetime, and reversibility are impaired by passivation and dendrite growth of the Zn anode. Here, this challenge is circumvented by an iodine post‐functionalized zeolitic imidazolate framework‐90 (ZIF‐90‐I) additive, in which the polycation absorbed on Zn anode can regulate solid–electrolyte interphase (SEI) formation in the 1 m Zn(TFSI)2 electrolyte and induce Zn2+ uniform deposition. Moreover, the I3−/I− redox can rejuvenate dead Zn and inhibit dendrites. With the ZIF‐90‐I additive, Zn plating/stripping at 99.5% Coulombic efficiency for 120 cycles is obtained in Zn||Ti cells at 20 mA cm−2/1 mAh cm−2. In addition, Zn||Zn cells show steady cycling for 1200 h at 5 mA cm−2/1 mAh cm−2 with stable overpotentials. The utilization rate of Zn reaches up to 68.6%. In situ optical microscopy reveals smooth, uniform Zn plating, and the Zn‐rejuvenated function from the I3−/I− redox couple. The refreshed SEI with the increase of Zn‐rich complexes, and nitrides from adsorbed polycations, are uniform and ZnF2‐rich in the Zn(TFSI)2 + ZIF‐90‐I electrolyte. The full Zn||air cells in Zn(TFSI)2 + ZIF‐90‐I electrolyte exhibit excellent cycling stability with stable polarization voltage at 0.1 mA/0.05 mAh cm−2.