Polypyrrole-Assisted Co3O4 Anchored Carbon Fiber as a Binder-Free Electrode for Seawater Batteries

An efficient, durable and cost-effective air electrode is essential to achieve a practicable metal-air battery. The conventional preparation of electrode uses polymer binders to ensure good physical contacts between catalysts and the electrode scaffold. However, the use of polymer binders introduces inevitable loss of the electrochemically active surface area and restricts access of the reactants, owing to the electrically insulating properties and hydrophobic properties of polymer binders. In this work, a binder-free air electrode is structured by using Co oxide anchored on carbon fiber tissues with the assistance of polypyrrole-doped carbon (PPy/C) through a simple infiltration technique. The fabricated binder-free electrode exhibits excellent bifunctional stability for seawater batteries, presenting a comparable performance to the binder-included Pt/C+IrO2 electrode.