Scalable Zn-Alloy Anode for High-Current-Density Aqueous Zinc-Ion Batteries

Both coating on Zn foil anode and solid electrolyte interphases engineered via electrolyte modification still face stability challenges under high current densities for aqueous Zn-ion batteries (AZIBs). Herein, high-current-density stable Zn-alloy anode with a large electrode size of 200 × 200 × 0.1 mm³ is developed. The results indicate that Sn alloy atoms preferentially segregate at heteroatom-concentrated grain boundaries and the alloy anode has a preferred orientation along the (002) plane during cycling, inhibiting dendrite growth and enhancing corrosion capability. These integrated merits enable a long lifespan for symmetric batteries even at 40 mA cm⁻² with 20 mAh cm⁻², and an excellent cycling stability for both coin- and pouch-type batteries at 2 A g⁻¹. This work provides an in-depth understanding of the effect of alloy element on Zn anode stability and meanwhile paves the way for scalable production and practical application of AZIBs.