Single (Ni, Fe) atoms and ultrasmall Core@shell Ni@Fe nanostructures Dual-implanted CNTs-Graphene nanonetworks for robust Zn- and Al-Air batteries

To meet the reaction kinetic demands of cathodic electrode in metal-air battery technology, we propose a novel bifunctional catalyst of single iron atoms, single nickel atoms, and core@shell Ni@Fe nanoparticles simultaneously confined in a porous interconnected carbon nanotubes/N-doped graphene nanonetwork (NiSAFeSA- Ni@Fe-NPs/CNTs-NGNS). The optimized NiSAFeSA-Ni@Fe-NPs/CNTs-NGNS catalyst exhibits excellent electrocatalytic activities, affording a positive onset potential of + 0.92 V along with a favorable 4e(-) pathway for ORR while delivering a low overpotential (eta) of 309 mV at 10 mA cm(-2) for OER in alkaline medium. The synergistic effects caused by the enhanced OER and ORR allow the NiSAFeSA-Ni@Fe-NPs/CNTs-NGNS air-cathode to produce high-performance Zn- and Al-air batteries with exceptional cell voltage, power density, and durability, surpassing most materials reported so far. The developed Zn- and Al-air batteries deliver cell voltages of 1.41 and 1.61 V with high power density of 163 and 184 mW cm(-2), respectively. Furthermore, they exhibit a stable cell voltage even after undergoing deformation testing and long-term charge-discharge operation of 170 h. This work suggests a promising candidate for high-performance metal-air battery applications.

Automated summary

We propose a novel catalyst that meets the reaction kinetics demands of metal-air battery and demonstrates excellent performance in both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). By enhancing the synergistic effects of OER and ORR, we have successfully developed high-performance zinc-air and aluminum-air batteries with exceptional cell voltage, power density, and durability, surpassing most existing materials.