Active site-engineered bifunctional electrocatalysts of ternary spinel oxides, M0.1Ni0.9Co2O4 (M: Mn, Fe, Cu, Zn) for the air electrode of rechargeable zinc–air batteries. Issue 39 (28th September 2017)

• Record Type: Journal Article
• Authors: Lu, Yi-Ting; Chien, Yu-Ju; Liu, Ching-Fang; You, Ting-Hsuan; Hu, Chi-Chang
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 39(2017)
• Page Start: 21016
• Page End: 21026
• Publication Date: 2017-09-28
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c7ta06302d
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : The active sites of M0.1 Ni0.9 Co2 O4 for the OER and ORR are successfully engineered for its application in rechargeable Zn–air batteries. Abstract : Discovering efficient and cost-effective catalysts for rechargeable metal–air batteries is one of the major scientific challenges in future energy storage/conversion technologies because of the sluggish kinetics of the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). Based on the octahedral site preference energy (OSPE) model, engineering the active sites of ternary M0.1 Ni0.9 Co2 O4 for the OER and ORR in alkaline solutions is demonstrated in this work. From the X-ray photoelectron spectroscopy (XPS) and OSPE models, Fe-doped NiCo2 O4 (Fe0.1 Ni0.9 Co2 O4 ) provides the highest Co 2+ /Co 3+ ratio and the lowest Ni 2+ /Ni 3+ ratio, leading to enhanced electrocatalytic activities toward both the OER and ORR in alkaline electrolytes from rotating ring disk voltammograms. In addition, all ternary oxides are examined as bifunctional electrocatalysts for the air electrode of rechargeable zinc–air batteries using the polarization curves of the ORR and OER in 6 M KOH in ambient air. The full-cell configuration using a Fe0.1 Ni0.9 Co2 O4 -coated air electrode exhibits a maximum power density of 150 mW cm −2 at a current density of 250 mA cm −2 in ambient air and facilitates long-term cycling stability (over 66.7 h at 10 mA cm −2 ). These results confirm the excellent bifunctional electrocatalytic activity of Fe0.1 Ni0.9 Co2 O4, which is considered to be a practical catalyst for the air electrode of rechargeable Zn–air batteries.