New graphene oxide-based catalyst boosts zinc-air battery performance

Researchers at CICATA-Legaria, the National Laboratory for Energy Conversion and Storage at Mexico’s Instituto Politécnico Nacional (IPN) in Mexico City, have developed a composite of pyridine-coordinated transition-metal nitroprussides and reduced graphene oxide (rGO) as a bifunctional pre-electrocatalyst for zinc-air batteries (ZABs). Testing cobalt, nickel, and copper versions of the material, the team found that each metal favors a different half of the battery’s oxygen chemistry, with the cobalt variant striking the best overall balance.

Rechargeable zinc-air batteries are attractive for their high theoretical energy density, low cost, and inherent safety, but their air cathode has to drive both the oxygen reduction reaction (ORR) during discharge and the oxygen evolution reaction (OER) during charging, reactions with sluggish kinetics that typically require different types of catalysts. The field’s benchmark catalysts, platinum for ORR and iridium or ruthenium oxides for OER, are scarce and expensive, pushing research toward cheaper first-row transition metals such as cobalt, nickel, and copper. Nitroprussides, a family of cyanometallate coordination polymers with the general formula T[Fe(CN)5NO], offered the team a synthetically simple, structurally tunable starting point for that search.

Read More Graphene-Info – Graphene industry portal