Heteroatoms Modulate the Copper Single Atom Catalytic Host Materials for Promoting the Redox Reaction in Aqueous Zinc‐Selenium Batteries

Abstract Aqueous zinc‐selenium (Zn‐Se) batteries have garnered much attention due to their inherent safety and high specific capacity. Unfortunately, the problem of sluggish redox reaction represents a significant obstacle to the development of aqueous Zn‐Se batteries. Here, a nitrogen‐phosphorus asymmetrically coordinated copper single atom catalytic host material (CuN₃P₁@C) is synthesized for an aqueous Zn‐Se battery. The CuN₃P₁@C host material exhibits a rich porous structure, high‐loading of Cu single atoms, and unique asymmetric coordination environment, which significantly reduces the reaction energy barrier for the redox reaction between Se and Zn, enhancing the electrochemical performance of the aqueous Zn‐Se battery. Consequently, the Se/CuN₃P₁@C cathode achieves a high specific capacity of 756 mAh g⁻¹ at 0.2 A g⁻¹ and cycling stability of 4 000 cycles at 5.0 A g⁻¹ (capacity decay of 0.0044% per cycle). Meanwhile, the conversion mechanism of an aqueous Zn‐Se battery is systematically explored via systematical characteristics and density functional theory calculations. This work opens up a novel approach to boosting the redox reaction of aqueous Zn‐Se batteries by modulating single atom‐based host materials via heteroatoms.