A nano-spherical nickel silicate coating regulates Zn deposition for durable aqueous zn-ion batteries

Aqueous zinc-ion batteries (AZIBs) are promising for large-scale energy storage, but the Zn anode still suffers from interface side reactions. Here, a nano-spherical nickel silicate (NSOQ) coating is constructed on zinc foil as an ion-regulating interfacial layer. At 1 mA cm −2 and 0.25 mAh cm −2 , the NSOQ-Zn//NSOQ-Zn symmetric battery cycles for 2750 h, about four times longer than bare Zn//Zn. At 1 mA cm −2 and 1 mAh cm −2 , the cycling life is extended by approximately six times. The NSOQ coating not only lowers the corrosion current but also inhibited hydrogen evolution, reduces the Zn nucleation overpotential, and increases the Zn 2+ transference number from 0.4 to 0.6. Morphological observations show that Zn initially deposits within the interparticle pores of the coating and then grows laterally, rather than forming vertically protruding dendrites. The simplified NSOQ layer model simulation of COMSOL further indicates that the NSOQ layer uniformly distributes the electric field and Zn²⁺ flux at the interface, thereby facilitating the uniform precipitation of zinc. The NSOQ-Zn//NH₄V₄O₁₀ still maintained a capacity of 132 mAh g −1 after 1000 cycles at a current of 3 A g −1 . These results identify NSOQ as an effective silicate-based interfacial layer for stabilizing Zn anodes in AZIBs.