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

摘要

The strategy of heteroatom doping and metal active sites can synergisticallypromote oxygen electrocatalysis. Especially, the combination of theoreticalsimulations with experimental results provides new opportunities to understandthe electrocatalytic mechanism. Herein, the 3D carbon nanosheetsaggregate 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 tooxygen reduction (E1/2 = 0.925 V) and evolution (E_(j = 10) = 1.54 V) reactions, surpassingthose of Pt/C-RuO_2 catalysts. The theoretical calculations reveal thatthe electronic interaction of cobalt sites and nitrogen-doped carbon matrixplays a critical role in boosting the bifunctional electrocatalytic performance.Additionally, the rechargeable Zn-Air battery (ZAB) assembled with aqueouselectrolyte exhibits the largest power density of 371.6 mW cm~(?2) and outstandingcycling durability (over 2000 h). Furthermore, all-solid-state cabletypeZAB delivers high flexibility with good cycling stability and high energyefficiency (76.5). This work will open a new avenue to adjust the metalcarbonsupport interaction for functional electrocatalysis via hierarchicalporous structure design.