Enabling Low-Temperature and High-Rate Zn Metal Batteries by Activating Zn Nucleation with Single-Atomic Sites

Aqueous zinc (Zn)-ion batteries have attracted increasing attentions owing to their low cost and intrinsic safety. Nevertheless, the sluggish kinetics at subzero temperatures severely exacerbate the Zn dendrite growth, which hinders their implementation in cold environ-ments. By virtue of high activity and maximum exposure of single atoms, Bi-N4 moieties were fabricated to serve as Zn nucleation sites to increase Zn nucleation kinetics toward high-rate and low-temperature Zn metal batteries. Benefiting from the boosted kinetics, the Bi-N4 species render a highly reversible and dendrite-free Zn plating/stripping behavior at 5 mA cm-2 with an average Coulombic efficiency of 99.4% over 1600 cycles at -30 degrees C, as well as a prolonged life up to 600 cycles in symmetric cells. Low-temperature full cells were also demonstrated with nearly 100% capacity retention after cycling at 0.5 A g-1 for 1400 cycles. This work shows the feasibility of single atoms in manipulating nucleation behaviors toward low-temperature metal batteries.