High Entropy Spinel Oxide As a Bifunctional Electrocatalyst for Rechargeable Zinc-Air Battery

Abstract

Rechargeable zinc-air battery (RZAB) represents one of the ‘beyond-the-lithium-ion’ battery technologies with great potential for renewable energy storage. It is safe, environmentally benign, and excellent potential for affordable applications in resource-limited countries, ranging from residential and industrial electricity supply, transport (e.g., electric vehicles) to mobile and consumer electronics markets. RZABs possess high theoretical specific energy density of 1086 Wh/kg, which is 5 times greater than that of the conventional lithium-ion battery (LIB). The key challenge that conspires against the widespread commercialization of RZAB is the sluggish oxygen reaction kinetics that impedes reversibility of the system. Thus, it has become quite critical to develop low-cost and high-performance bifunctional electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) [1,2].High entropy materials (HEMs) have emerged as electrocatalysts for ORR and OER. HEMs contain five or more metals in equal proportions. Their unique conformational entropy and physico-chemical properties (including lattice distortion, synergistic effects amongst the different metals, and rich defect chemistries) promise to improve the kinetics of ORR / OER and electrochemical cycling stability. In this work, the high entropy spinel oxide, (CoCuFeMnNi)3O4 supported on conductive carbon has been synthesized and characterised using XRD, XPS, HRTEM, SEM and others. Preliminary electrochemistry shows improved ORR/OER kinetics. This presentation will discuss the performance of the initial lab-based RZAB using this electrocatalyst. References AB Haruna and KI Ozoemena, Manganese-based bifunctional electrocatalysts for zinc-air batteries, Opin. Electrochem. 2020, 21, 219-224AK Ipadeola, AB Haruna, L Gaolatlhe, AK Lebechi, J Meng, QQ Pang, K Eid, AM Abdullah, and KI Ozoemena, Efforts at Enhancing Bifunctional Electrocatalysis and Related Events for Rechargeable Zinc-Air Batteries; ChemElectroChem 2021, 8, 3998-4018