Nickel-Anchored N-Enriched CNTs Nucleated via CoNi Alloy for Sustainable Zinc–Air Batteries

Abstract Rationally designed, multifunctional, highly efficient, robust, and cost-effective non-precious-metal-based bifunctional oxygen electrocatalysts have attracted substantial interest in the field of clean energy over the last few decades. A catalyst designed with surface charge-storage-like properties is of great significance for sustainable Zn–air batteries. However, preparing such an interface requires complex synthesis and purification. Here, we used binary CoNi alloy nanoparticles as nuclei in a single-step pyrolytic synthesis to create a novel hybrid of nickel-anchored nitrogen-doped carbon nanotubes (CNTs). The improved sample showcases a bifunctional interface capable of both oxygen evolution and reduction, along with efficient EDLC-type surface charge storage. As a result, the hybrid structure exhibits capacitive characteristics, making it a potential candidate for supercapacitor-assisted zinc–air battery configurations. This superstructure (CoNi/CNTs) enabled ZAB to reach an open-circuit voltage of 1.447 V and a power density of 141.29 mW/cm2. This promising performance is attributed to the active surfaces of the N-doped compartmentalized CNTs. Furthermore, the synergistic interactions between the catalytically active carbon centers, anchoring ultrasmall Ni clusters, and CoNi alloy nanoparticles further improve the catalytic activity. Our findings emphasize the potential for clean-energy applications by demonstrating the practical benefits of integrating charge-storage-like properties in the catalyst architecture for sustainable Zn–air batteries.