FeCo2O4/CNF Prepared by Electrospinning as Bifunctional Oxygen Electrode for Alkaline Metal-Air Battery Applications

Autor: V. Baglio, C. Busacca, A. Di Blasi, O. Di Blasi, E. Modica, M. Girolamo, M. Bottari, A.S. Aricò, V. Antonucci, C. Alegre
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: 71st Annual Meeting of the International Society of Electrochemistry, Belgrade (Serbia) online, 30/08/2020-04/09/2020
info:cnr-pdr/source/autori:V. Baglio, C. Busacca, A. Di Blasi, O. Di Blasi, E. Modica, M. Girolamo, M. Bottari, A.S. Aricò, V. Antonucci, C. Alegre/congresso_nome:71st Annual Meeting of the International Society of Electrochemistry/congresso_luogo:Belgrade (Serbia) online/congresso_data:30%2F08%2F2020-04%2F09%2F2020/anno:2020/pagina_da:/pagina_a:/intervallo_pagine
Popis: A new way to produce and store electrical energy is necessary to address future energy demands and reduce polluting emissions. Rechargeable alkaline metal-air batteries are envisaged as commercially viable energy storage devices due to their high theoretical energy densities respect to lithium-ion batteries. However, they do not still offer adequate practical energy density and life cycle due to critical problems arising from the positive electrode, such as slow kinetics of the oxygen reduction (ORR) and oxygen evolution (OER) reactions. In the last few years, research was focused on the development of highly efficient oxygen reduction/evolution catalysts based on transition metals, such as Co, Fe, Mn, La, etc, in the form of mixed oxides (perovskites, spinels, etc.), or advanced carbon materials. Co-based catalysts have been thoroughly investigated for the ORR/OER, and, usually, Co3O4 is the most employed formulation. However, the electrical conductivity of bare Co3O4 is not appropriate for the application in most of these devices. Other transition metals (Ni, Fe, Mn, etc.) can partially replace Co atoms in the Co3O4 spinel structure, improving its electronic conductivity while promoting oxygen evolution. Another approach is to combine these oxides with carbon nanostructures, in particular graphitic ones, in order to maintain suitable stability under cycling operation. Recently, carbon nanofibers (CNF) synthesized by electrospinning, modified with a spinel Co3O4 [1] or a combination of cobalt oxide and metallic cobalt (CoO-Co/CNF) [2] or loaded with Nickel-cobaltite [3], were investigated in our laboratories as bifunctional air electrodes showing good reversibility and stability. In this work, Fe partially replaces Co atoms in the Co3O4 spinel structure, leading to a FeCo2O4/CNF, by using the same electrospinning preparation procedure previously reported. The FeCo2O4/CNF catalyst is physico-chemically studied in terms of structure, morphology and surface properties; these features are correlated to the electrochemical behavior for the oxygen reduction (ORR) and oxygen evolution (OER) reactions in comparison with previously developed Co3O4/CNF [1] and state-of-the-art materials. An outstanding onset potential towards the OER of 1.40 V vs. RHE is observed, which is 140 and 250 mV lower compared to the pure spinel (Co3O4/CNF) and Pt/Vulcan, respectively. A remarkable reversibility (?E = EOER - EORR) value of 495 mV is obtained, due to a good activity also for the ORR. To assess the stability of the catalysts for rechargeable alkaline metal-air batteries, cycling operation and chronopotentiometric experiments are carried out, showing promising results. References [1] C. Alegre, C. Busacca, A. Di Blasi, O. Di Blasi, A.S. Aricò, V. Antonucci, E. Modica, V. Baglio, Journal of Energy Storage 23 (2019) 269-277. [2] C. Alegre, C. Busacca, O. Di Blasi, V. Antonucci, A.S. Arico, A. Di Blasi, V. Baglio, Journal of Power Sources 364 (2017) 101-109. [3] C. Alegre, C. Busacca, A. Di Blasi, et al., ChemElectroChem 7 (2020) 124-130.
Databáze: OpenAIRE
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