Highly Active and Durable Nanocrystal-Decorated Bifunctional Electrocatalyst for Rechargeable Zinc-Air Batteries

A highly active and durable bifunctional electrocatalyst that consists of cobalt oxide nanocrystals (Co3O4 NC) decorated on the surface of N‐doped carbon nanotubes (N‐CNT) is introduced as effective electrode material for electrically rechargeable zinc–air batteries. This active hybrid catalyst is synthesized by a facile surfactant‐assisted method to produce Co3O4 NC that are then decorated on the surface of N‐CNT through hydrophobic attraction. Confirmed by half‐cell testing, Co3O4 NC/N‐CNT demonstrates superior oxygen reduction and oxygen evolution catalytic activities and has a superior electrochemical stability compared to Pt/C and Ir/C. Furthermore, rechargeable zinc–air battery testing of Co3O4 NC/N‐CNT reveals superior galvanodynamic charge and discharge voltages with a significantly extended cycle life of over 100 h, which suggests its potential as a replacement for precious‐metal‐based catalysts for electric vehicles and grid energy storage applications. Fully charged: We introduce cobalt oxide nanocrystals decorated on N‐doped carbon nanotubes created by a facile method based on hydrophobicity as a bifunctional air electrode catalyst for rechargeable zinc–air batteries. The hybrid catalyst performs well in the oxygen reduction and oxygen evolution reactions and has an excellent electrochemical durability. This hybrid catalyst created by a facile synthetic method is very promising as a highly efficient bifunctional catalyst for electrically rechargeable zinc–air batteries.