A novel bifunctional catalyst of Ba_0.9Co_0.5Fe_0.4Nb_0.1O_{3鈭?span style='font-style: italic'>未} perovskite for lithium-air battery

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• 作者：Chao Jin ; Zhibin Yang ; Xuecheng Cao ; Fanliang Lu ; Ruizhi Yang
• 关键词：Bifunctional catalyst ; Oxygen reduction reaction ; Oxygen evolution reaction ; Perovskite oxide ; Lithium&ndash ; air battery
• 刊名：International Journal of Hydrogen Energy
• 出版年：14 February, 2014
• 年：2014
• 卷：39
• 期：6
• 页码：2526-2530
• 全文大小：761 K

文摘

Ba_0.9Co_0.5Fe_0.4Nb_0.1O₃ (BCFN) perovskite has been synthesized by a solid-state reaction method, and characterized by XRD, SEM, BET. This oxide has a porous structure and a specific surface area of 10.24聽m²聽g^鈭? after ball-milled 24聽h. The catalytic activity of the oxide for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) in 0.1聽M KOH solution has been studied by using a rotating ring-disk electrode (RRDE) technique. RRDE results show that the ORR mainly favors a direct four electron pathway, and a maximum cathodic current density of 鈭?.70聽mA聽cm^鈭? at 2500聽rpm was obtained, which is close to that of Pt/C (20聽wt.% Pt on carbon) electrocatalyst in the same testing conditions. Compared with behaviors of pure C and Pt/C electrode, a lower onset potential of BCFN for OER is observed, and a bigger anodic current at the same applied potential is obtained. Considering small surface area of the BCFN catalyst, a big overpotential is given in the discharge-charge curves. However, the outputs of 2032 coin Li-air batteries in a dry gas mixture composed of 80聽vol.% pure N₂ and 20聽vol.% pure O₂ demonstrated that BCFN could be a potential bifunctional catalyst for the Li-air battery.