“Setaria viridis”-like cobalt complex derived Co/N-doped carbon nanotubes as efficient ORR/OER electrocatalysts for long-life rechargeable Zn–air batteries

Abstract

The development of efficient and facile strategies to prepare metal and nitrogen codoped carbon (M–N–C) materials as oxygen electrocatalysts in rechargeable Zn–air batteries with high performance and a long life is challenging. Herein, we report a simple route to synthesize cobalt and nitrogen codoped carbon nanotubes (denoted as Co/N-CNT) as bifunctional oxygen electrocatalysts for rechargeable Zn–air batteries (ZABs). The Co/N-CNT are fabricated through the surface modification of carbon nanotubes with cobalt salt and melamine followed by pyrolysis, which delivers outstanding oxygen reduction/evolution reaction (ORR/OER) activity with a low overall potential gap (ΔE = 0.77 V) and remarkable durability. The home-made Zn–air batteries exhibit a high power density (130 mW cm⁻²vs. 82 mW cm⁻²), a large specific capacity of (864 mA h g⁻¹_Znvs. 785 mA h g⁻¹_Zn), and a long cycling life (1200 h vs. 60 h) in both aqueous and solid media. This work opens an avenue for the reasonable surface modification of carbon nanotubes with various metals and heteroatoms to achieve high-performance electrocatalysts for clean and sustainable energy conversion and storage devices.