Advantageous Configurative Heteroatoms-Doped Carbon Foams Design and Application for Ultrahigh-Powered Zn-Air Batteries

Heteroatoms-doped carbon is considered a promising electrocatalyst to overcome the sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) which are the core processes for many energy conversion devices. Much research has been done to screen carbon-based catalysts for ORR or OER. Catalytic activity is not satisfactory to both sides, and the unclear catalytic mechanism greatly limits their wide application. Here, we describe a family of heteroatoms (Fe, N, and S)-codoped carbon foams with excellent electrocatalytic activity for both ORR and OER, giving an exceptional small overpotential of 0.688 V, superior to the case for commercial 20% Pt/C. Remarkably, the rechargeable Zn-air battery with the catalysts as the air cathode delivers an ultrahigh power density of 578 mW cm(-2), along with an excellent charge and discharge cycling stability beyond 250 h (1500 cycle), surpassing that of most bifunctional catalysts reported to date. More importantly, the perfect combination of experiments and DFT calculations confirms that the unique configuration of FeN4/S-N-Gra endows the heteroatoms-codoped carbon foams with excellent electrocatalytic activity and stability. The DFT-guided advantageous configurative heteroatoms-doped carbon foams as bifunctional catalysts for ORR and OER may provide guidance for the design of nonprecious metal catalysts in the practical application of Zn-air batteries.