Roll-to-roll fabrication of integrated cathodes enabled by asymmetric dual-atom catalysts for bipolar stacking ampere-hour-scale Zn–air batteries

Zn-air batteries (ZABs) represent a highly promising electrochemical energy storage technology, yet their practical deployment remains constrained by several fundamental challenges, including sluggish oxygen reaction kinetics at the cathode, limited power output and capacity in conventional device architectures. Herein, we demonstrate an efficiently integrated strategy to systematically address these issues. First, a metal-semimetal dual-atom catalyst consisting of Fe-Se dual-atom sites (FeSe-NC) is synthesized, whose unique electronic structure and metal-semimetal synergistic effects significantly enhanced oxygen electrocatalytic activity, achieving a half-wave potential of 0.920 V and a turnover frequency of 0.77 e^- site^-1 s^-1. Furthermore, a scalable roll-to-roll process was developed to fabricate an integrated air cathode with a highly uniform catalytic layer structure. Ultimately, the electrode was employed in a bipolar stacking cell configuration. Benefiting from these multi-level innovations, the assembled ampere-hour-scale ZABs delivered a high power output of 3.5 W, a large capacity of 6.09 Ah, and long-term cycling stability over 60 h at 1.0 A. This work systematically advances the development of high-performance, long-lasting ZABs through catalyst design, electrode engineering, and device configuration optimization, providing a viable technical pathway for their industrialization.