Tailoring Electronic Structure of Atomically Dispersed Metal–N₃S₁ Active Sites for Highly Efficient Oxygen Reduction Catalysis

Rational design of oxygen electrocatalysts with high catalytic activity and long-term durability is currently a severe challenge for rechargeable Zn–air batteries. Here, we highlighted an electronic structure engineering on Cu-based catalyst with atomically dispersed Cu–N3S1 active sites, representing as highly active electrode material for oxygen reduction. The structurally-new Cu–N3S1 species shows unique electron interactions with both phosphorus atoms/carbon support, which not only activate the electron transfer around the Cu–N3S1 sites but also enhance the interaction with oxygenated species, resulting in a promoting reaction kinetics process. As expected, this catalyst exhibits superior catalytic activity for oxygen reduction and evolution. A rechargeable flexible solid Zn–air battery based on this catalyst behaves superior performance of a high open-circuit voltage (1.41 V), a large power density (138.2 mW/cm2), and a small charge/discharge voltage gap (0.72 V at 2.0 mA cm–2) even under different bending angles. Specifically, this strategy is general and can be extended to other metal single atom catalyst systems (such as Fe–N3S1 species). This work will open a new avenue to design structurally-new single atom catalysts for energy-related field.