Tuning Co‐Catalytic Sites in Hierarchical Porous N‐Doped Carbon for High‐Performance Rechargeable and Flexible Zn‐Air Battery

Abstract The strategy of heteroatom doping and metal active sites can synergistically promote oxygen electrocatalysis. Especially, the combination of theoretical simulations with experimental results provides new opportunities to understand the electrocatalytic mechanism. Herein, the 3D carbon nanosheets aggregate with highly branched carbon nanotubes and cobalt active sites (CoCNTs/PNAs) is prepared via the facile self‐assembly‐pyrolysis strategy. The CoCNTs/PNAs electrocatalysts exhibit superior bifunctional activities to oxygen reduction ( E 1/2 = 0.925 V) and evolution ( E j = 10 = 1.54 V) reactions, surpassing those of Pt/C‐RuO 2 catalysts. The theoretical calculations reveal that the electronic interaction of cobalt sites and nitrogen‐doped carbon matrix plays a critical role in boosting the bifunctional electrocatalytic performance. Additionally, the rechargeable Zn‐Air battery (ZAB) assembled with aqueous electrolyte exhibits the largest power density of 371.6 mW cm −2 and outstanding cycling durability (over 2000 h). Furthermore, all‐solid‐state cable‐type ZAB delivers high flexibility with good cycling stability and high energy efficiency (76.5%). This work will open a new avenue to adjust the metal‐carbon support interaction for functional electrocatalysis via hierarchical porous structure design.