Anticorrosion and Hydrophobic Surface Protection Inducing Dendrite-Free Zn Anode for Aqueous Zn-Ion Batteries

Zinc is widely used as an anode in zinc-ion batteries (ZIBs) due to its nontoxicity, favorable theoretical specific capacity, and low oxidation-reduction potential. Nevertheless, irreversible Zn dendritic growth and unavoidable side reactions limit its cyclic stability and high-rate capability. This research puts forward a surface protection strategy by introducing a hydrophobic polyvinylidene fluoride and carborundum nanocoating (PVDF-SiC) coating on the surface of Zn anode to synergistically restrain side reactions and Zn dendrites. PVDF improves the hydrophobicity of Zn anode at the solid-liquid interface, which can avoid side reactions between Zn anode and water. SiC nanoparticles with high porosity and small size pore can also homogenize the Zn2+ flux, which can cause uniform Zn deposition and inhibit Zn dendrite growth. The hydrophobic PVDF-SiC@Zn symmetric battery accordingly exhibits an invariable overvoltage (<40 mV) after 780 h at 1 mA cm(-2) with 0.25 mAh cm(-2). Simultaneously, constant and convertible Zn deposition in PVDF-SiC@Zn//Ti asymmetric battery is implemented. The PVDF-SiC@Zn//V2O5 full battery exhibits 68% capacity retention after 400 cycles. The porous/hydrophobic PVDF-SiC composite modification efficiently restrains the side reactions and Zn dendrite growth on the Zn anode, providing an innovative idea for achieving long-life ZIBs.