Regulation and Stabilization of the Zinc Metal Anode Interface by Electroless Plating of a Multifunctionalized Polydopamine Layer.

A novel electroless plating technique is utilized by coating a polydopamine layer on zinc foil (Zn@PDA) to regulate the deposition and growth of zinc dendrites, as well as suppress the occurrence of hydrogen evolution and passivation products for aqueous zinc-ion batteries. Polydopamine (PDA) has a strong adsorption ability on Zn foil due to the formation of a bidentate bonding during the electroless plating. Further, it indicates that the abundant hydroxyl groups of PDA react as zinc-philic sites to adsorb Zn and further undergo redox by forming carbonyl groups to effectively induce the uniform deposition and growth of zinc dendrites. Meanwhile, the strong coordination of PDA and Zn will weaken the solvated structure between Zn and HO molecules, resulting in an enhanced ionization energy of HO and inhibited hydrogen evolution reaction. Thus, Zn@PDA can maintain stable cycling over 900 h at 0.2 mA cm, and a high coulombic efficiency of average 98.5% at 2 mA cm. Moreover, the validity of Zn@PDA has been verified using the Zn@PDA||self-standing VS@stainless steel (VS@SS) full battery, which displays an impressive capacity retention of 81.3% after 1000 cycles without sacrificing the rate performance. This work provides a simple, reliable, and harmless method to achieve high-performance aqueous zinc-ion batteries.