Edge-electron induced ferrimagnetic effect to accelerate interfacial desolvation kinetics toward dendrite-free Zn metal batteries

Rechargeable aqueous zinc metal batteries (AZMBs) have garnered significant attention for large-scale energy storage. However, they are hindered by the sluggish Zn(H 2 O) 6 2+ desolvation kinetics, leading to uneven Zn deposition as well as side reactions of active water molecules for the formation of hydrogen evolution reaction (HER). Herein, high spin-state ferrimagnetic interphase of c spinel zinc ferrite (ZFO) has been pioneered to serve as artificial interphase on metallic Zn anode (ZFO@Zn). Specifically, high-spin Fe 3+ center enhances electron delocalization and the spinel crystal structure of ZFO layer facilitates the interfacial ion transfers, catalytically reducing the barriers of Zn 2+ desolvation and atom diffusion. Meanwhile, the micro-magnetic field self-motivates interfacial ion flux and separates the active molecules, enabling uniform Zn deposition without HER. The as-fabricated cell employed with ZFO@Zn achieved an impressive cumulative capacity exceeding 3500 mAh cm −2 at 30 mA cm −2 , demonstrating its remarkable kinetics and stability. The assembled vanadium-based full cell exhibits superior performance of 411.1 mAh g −1 at 10 A g −1 and maintained the capacity-retention of 90.7% after 3000 cycles at 5 A g −1 . Impressively, the large-areal pouch cell with ZFO@Zn anode stabilizes for 150 cycles, underscoring the potential of magnetic spinel materials for the commercialization of AZMBs. Ferrimagnetic nanoscale spinel ZFO was used to construct an artificial layer on the surface of Zn anode. Abundant high-spin Fe 3+ catalytic active sites accelerate electrode reaction kinetics through electron delocalization effects. The 3D structured channels formed by spinel crystal arrays facilitate ionic diffusion. The restriction of disordered ion flow by the interfacial micromagnetic field results in self-motivated Zn deposition. • The three-dimensional spinel structure of ZFO enhances ion diffusion kinetics. • High-spin Fe 3+ metal centers catalytically reduce desolvation energy barriers. • Ferrimagnetic ZFO interphase layers self-regulate ion flux to induce uniform Zn deposition. • ZFO-modified Zn anodes demonstrate excellent stability and rate performance.