Delocalized Electron Engineering of MXene-Immobilized Atomic Catalysts toward Fast Desolvation and Dendritic Inhibition for Low-Temperature Zn Metal Batteries

Rechargeable low-temperature aqueous zinc metal batteries (LT-AZMBs) are considered as a competitive candidate for next-generation energy storage systems owing to increased safety and low cost. Unfortunately, sluggish desolvation kinetics of hydrated [Zn(H2O)x]2+ and inhomogeneous ion flux cause detrimental hydrogen evolution reactions (HER) and Zn dendrite growth. Herein, the atomic iron well-implanted onto MXene via defect capture (SAFe@MXene) has been initially proposed to modulate Zn plating. The SAFe@MXene serves as kinetic promoters to enhance interfacial desolvation of [Zn(H2O)x]2+ to prevent HER and uniformizes Zn2+ flux for smooth deposition, as confirmed by theoretical simulation, Raman and electrochemical tests. Consequently, under 0 °C, the SAFe@MXene-modulated Zn electrodes deliver long-term stability of 800 h with lower overpotentials even at 5 mA cm–2 or higher plating/stripping capacity. The full cell with a MnO2 cathode stabilizes a high capacity-retention of nearly 100% after 1000 cycles at 1 A g–1, suggesting great promise for high-performance LT-AZMBs.