In-situ micro-battery etching induced 3D Zn with amorphous interfacial coating for high-stable Zn metal batteries

Abstract

Zn metal is one of the most prospective anodes for large-scale energy storage owing to its high volumetric capacity and safety. However, commercialization of the aqueous Zn metal batteries (AZMBs) is impeded by uneven Zn deposition and undesirable reaction issues. Herein, an in-situ micro-battery etching strategy is proposed to realize surface coating and 3D Zn construction simultaneously. It is worth noting that the amorphous Zn²⁺-intercalated ammonium vanadate (A-ZNVO) coating with abundant oxygen vacancy could not only inhibit the severe interface parasitic reactions but also facilitate the quick transmission of Zn²⁺. Beyond that, the 3D porous structure could reduce the local current density and induce uniform Zn deposition. As a result, such 3D Zn@A-ZNVO electrode ensures a remarkably long cycle lifespan of over 3700 h when a current density of 1 mA cm⁻² is applied. By contrast, the bare Zn could only cycle for 110 h and encounter short-circuit subsequently. Meanwhile, the 3D Zn@A-ZNVO anode also exhibits superior rate capability and above-average Coulombic efficiency (99.55 %). Moreover, the full cell could retain 85.2 % of discharge capacity even after 900 cycles under 1 A g⁻¹. This facile and multifunctional strategy offers a unique insight into the modification of metal-based electrodes.