Ternary Spinel MCo2O4 (M = Mn, Fe, Ni, and Zn) Porous Nanorods as Bifunctional Cathode Materials for Lithium鈥揙2 Batteries

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• 作者：Saad Gomaa Mohamed ; Yuan-Quei Tsai ; Chih-Jung Chen ; Yi-Ting Tsai ; Tai-Feng Hung ; Wen-Sheng Chang ; Ru-Shi Liu
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：June 10, 2015
• 年：2015
• 卷：7
• 期：22
• 页码：12038-12046
• 全文大小：681K
• ISSN：1944-8252

文摘

The development of Li鈥揙₂ battery electrocatalysts has been extensively explored recently. The Co₃O₄ oxide has attracted much attention because of its bifunctional activity and high abundance. In the present study, toxic Co²⁺ has been replaced through the substitution on the tetrahedral spinel A site ions with environmental friendly metals (Mn²⁺, Fe²⁺, Ni²⁺, and Zn²⁺), and porous nanorod structure are formed. Among these spinel MCo₂O₄ cathodes, the FeCo₂O₄ surface has the highest Co³⁺ ratio. Thus, oxygen can be easily adsorbed onto the active sites. In addition, Fe²⁺ in the tetrahedral site can easily release electrons to reduce oxygen and oxidize to half electron filled Fe³⁺. The FeCo₂O₄ cathode exhibits the highest discharging plateau and lowest charging plateau as shown by the charge鈥揹ischarge profile. Moreover, the porous FeCo₂O₄ nanorods can also facilitate achieving high capacity and good cycling performance, which are beneficial for O₂ diffusion channels and Li₂O₂ formation/decomposition pathways.