Non-Precious Metal Oxides As Cathode Electrocatalysts for Lithium-Air Batteries

Non-Precious Metal Oxides as Cathode Electrocatalysts for Lithium-Air Batteries

Mariana Souza, Ayad Nacy, Suzana Meira and Eranda Nikolla

Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI, 48202

    Li-air is a promising energy storage technology due to its high theoretical specific energy and energy storage capacity.¹ Main obstacles that limit the efficiency of these systems (the ability to reach theoretical specific energies) include the overpotential losses induced by the electrochemical reactions (oxygen reduction (ORR) and Oxygen evolution (OER)) occurring at on the cathode. It has been recently shown that these overpotential losses could be lowered by incorporating an active electrocatalyst on the cathode surface.² Noble metal nanoparticles (such as gold³, platinum³ and palladium⁴) supported on porous carbon cathodes for Li-air have shown to lower overpotential losses induced by ORR and OER. However, these metals are fairly expensive, making the discovery of less expensive electrocatalysts for ORR and OER critical in order for these systems to become economically feasible.

    In this contribution, we show our efforts in designing robust non-precious metal heterogeneous electrocatalysts for Li-air cathodes. We find that the incorporation of layered nickelate oxide electrocatalysts in Li-air cathodes significantly increases the decomposition rate for Li₂O₂ (discharge product) during the charging.⁵We show using controlled electrochemical studies that nickelate oxides lower the activation energies for OER and enhance cell stability during cycling as compared to traditional carbon-based cathodes.  These findings open up opportunities for incorporation of these non-precious metal oxides as cathode electrocatalysts for Li-air batteries.  

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