Self-Converted Scaffold Enables Dendrite-Free and Long-Life Zn-Ion Batteries

Zn-ion batteries are fascinating owing to their inherent safety and high theoretical capacity. However, dendrite-free growth is challenging, limiting highly stable plating for long-life batteries. Herein, a new, conceptual ultra-stable self-converted scaffold (SCS) Zn anode is reported that enables dendrite-free plating by guiding the deposition of Zn to specific areas. The SCS is naturally transformed from a zincophilic yet resistive nucleation seed. As a sufficient amount of Zn is plated onto these nucleation seeds, they undergo self-conversion into a resistive scaffold, thereby losing their Zn affinity, and effectively directing the Zn plating toward the less resistive basal plane by repelling the electrons. The unique electrode demonstrates exceptional stability, effectively controlling dendrite-free growth for thicknesses of up to 120 µm even in open-plating environments with an impressive areal capacity of 60 mAh cm⁻². Moreover, in full cell configuration, the SCS shows a superior long cycle-life of 3000 cycles. The newly discovered dendrite-free plating mechanism is also demonstrated.