Bridging Molecular Precision and Device Functionality With Triazole Based Cobalt Catalyst for Cross‐Platform Rechargeable Metal‐Air Batteries

ABSTRACT

Rechargeable metal‐air batteries offer exceptional theoretical energy densities but require durable bifunctional electrocatalysts that efficiently mediate oxygen reduction (ORR) and oxygen evolution (OER). Here, a triazole‐based cobalt complex (CoTzN) is developed to bridge molecular‐level mechanistic understanding with practical device integration. In homogeneous media, CoTzN catalyzes bidirectional ORR/OER, while electrochemical and spectroelectrochemical studies identify key Co(III)–OOH and Co(III)–O• intermediates. These molecular insights guide catalyst heterogenization on carbon nanotubes through π–π interactions (CoTzN‐P) and covalent amide anchoring (CoTzN‐C). CoTzN‐C exhibits enhanced charge transfer, stability across pH 7–14, and a highly selective four‐electron ORR pathway (n ≈ 3.95) with <5% H ₂ O ₂ production. Extended electrolysis demonstrates robust bifunctional activity with Faradaic efficiencies of ≈91% for ORR and ≈89% for OER. Importantly, CoTzN‐C functions as a bifunctional air cathode across two distinct rechargeable metal–air battery platforms. A quasi‐solid‐state Zn‐air battery sustains >450 rapid charge‐discharge cycles over ≈30 h, while a non‐aqueous Li‐air battery operates for 80 prolonged cycles (≈160 h). This molecular‐to‐device framework demonstrates how coordination‐level catalyst design can be translated into robust hybrid electrodes for cross‐platform rechargeable metal–air batteries.