Fabrication of Core–Shell α-Fe2O3@ Li4Ti5O12 Composite and Its Application in the Lithium Ion Batteries
2014
Chen, Ming | Li, Wei | Shen, Xiao | Diao, Guowang
In this work, a novel carbon-free core–shell α-iron oxide (α-Fe₂O₃)@ spinel lithium titanate (Li₄Ti₅O₁₂, LTO) composite has been synthesized via a facile hydrothermal process. Element mapping confirmed the core–shell structure of α-Fe₂O₃@LTO. The effects of various experimental parameters, including thickness of TiO₂ coating, reaction temperature, and time on the morphologies of the resulted products, were systematically investigated. The electrochemical measurements demonstrate that uniform α-Fe₂O₃ ellipsoids are coated with LTO to avoid forming a solid electrolyte interface (SEI) layer, to reduce initial capacity loss, and to improve the reversibility of α-Fe₂O₃ for Li ion storage. Compared with naked α-Fe₂O₃ ellipsoids, the α-Fe₂O₃@LTO composites exhibit lower initial capacity loss, higher reversible capacity, and better cycling performance for lithium storage. The electrochemical performance of α-Fe₂O₃@LTO composite heavily depends on the thickness and density of LTO coating shells. The carbon-free coating of LTO is highly effective in improving the electrochemical performance of α-Fe₂O₃, promising advanced batteries with high surface stability and excellent security.
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