Basal Plane Graphene Coated Zn Powder for High Performance Aqueous Zn Metal Batteries

Aqueous zinc metal batteries (AZMBs) suffer from Zn surface degradation caused by dendrite growth, corrosion, and electrolyte side reactions. Zn powder is an essential component for flexible electrodes, enhanced electrolyte accessibility, and precise control of areal capacity. However, its application is severely limited by pronounced surface failure. Here, a graphene coating is applied to Zn powder via a shear-stress-driven dry process, forming a basal plane-dominated protective layer. This coating suppresses the surface degradation by simultaneously passivating the surface, regulating the interfacial Zn²⁺ solvation structure, and establishing epitaxial Zn metal deposition toward the (002) crystallographic orientation. The resulting graphene-coated Zn powder (Gr_Zn) exhibits stable cycling with a low voltage hysteresis of 16.1 mV over 640 h at 1 mA cm^-2, outperforming zinc foil and bare Zn powder electrodes. Moreover, Gr_Zn delivers high-rate capability and exceptional high areal capacity (>20 mAh cm^-2) in full-cell and pouch-cell configuration.