Anode-Free Zinc-Bromine Batteries Enabled by a Simple Prenucleation Strategy

The design of anode-free zinc (Zn) batteries with high reversibility at high areal capacity has received significant attention recently, which is quietly challenging yet. Here, a Zn alloyed interface through electroplating is introduced, providing homogeneous Zn prenucleation sites to stabilize subsequent Zn nucleation and plating. By employing Zn-Cu alloy as a module, the complementary simulations and characterizations confirm that the prenucleation alloyed interfaces achieve a homogeneous electric field distribution and greatly enhance the stability of the Zn anode. Accordingly, the Zn//Zn-Cu@Cu half-cells show a long cycle life of over 900 h and an average Coulombic efficiency (CE) of 99.8% at an areal capacity of 10 mAh cm^-2. The assembled anode-free zinc-bromine (Zn-Br₂) battery exhibits an attractive stable cycling of 11 000 cycles at 1 mAh cm^-2, while over 1000 cycles at the higher areal capacity of 10 mAh cm^-2. Excitingly, the Zn-Br₂ pouch cell with a capacity of 1000 mAh operates stably over 50 cycles, and achieves successful integration with photovoltaic systems. This anode-free Zn-Br₂ batteries constructed through a prenucleation strategy offer new insights into the potential for large-scale energy storage applications.