Hierarchically Mesoporous Graphene Networks Modulate Homogeneous Two‐Electron Redox Chemistry for Highly Reversible and Stable Zinc‐Air Batteries

Abstract The emerging two‐electron (2e − ) redox Zinc‐air batteries (ZABs) in neutral electrolytes have attracted substantial research interest due to their better reversibility and stability compared to alkaline ZABs. However, the generation of nonconductive discharge products (ZnO 2 ) raises kinetics and stability challenges for the design of air cathodes. Herein, a redox‐homogenization electrochemistry approach is reported to accelerate the reversible conversion of ZnO 2 and promote the 2e − /O 2 reaction. The conductive graphene framework, featuring ultrahigh surface areas and high electrical/ionic conductivity, effectively reduces local current densities, thus effectively homogenizing the 2e⁻ redox reaction. Additionally, the hydrophobic 3D network not only diminishes the nucleation barrier but also restricts the growth of ZnO 2 within the mesopores, achieving the homogenization of discharge products and robust reaction kinetics. The fabricated neutral ZABs exhibit a low polarization of 0.43 V and excellent stability beyond 580 h at 0.5 mA cm −2 , most importantly, a benchmark energy efficiency of 75.4% at 0.1 mA cm −2 and 59.5% at 10 mA cm −2 . This work provides a blueprint for constructing advanced carbon cathodes for metal‐air batteries.