Pine-Leaf-Shaped α-Fe2O3Micro/Nanostructures with a Preferred Orientation along the (110) Plane for Efficient Reversible Lithium Storage

Abstract

© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Pine-leaf-like α-Fe 2 O 3 micro/nanostructures with (110)-facet orientations are prepared by a hydrothermal process using Mg 2+ as an inducer and are investigated as conversion-type anode materials for lithium-ion batteries (LIBs). The unique micro/nanostructured building blocks significantly shorten the diffusion distance for lithium ions and improve the kinetics of the lithium ion extraction/insertion process, and the unique hierarchical morphology provide buffer space for the volume change of the electrode during the charge–discharge processes. Thus, favorable performances for lithium storage are demonstrated for the micro/nanostructured α-Fe 2 O 3 electrodes. In addition, the facet orientation of the particles is also found to have a substantial impact on the electrode performance, and the growth of the micro/nanoparticles in a preferred orientation along the (110) plane facilitated the anisotropic diffusion of lithium ions along channels in the [1 (Formula presented.) 00] direction. From the dual benefits of the stable hierarchical micro/nanostructure and the preferred growth of the particles along the (110) plane, excellent electrochemical performance with a reversible capacity of up to 915 and 565 mA h g −1 at rates of 100 and 5000 mA g −1 , respectively, and a capacity retention of 690 mA h g −1 at 1000 mA g −1 after 200 cycles is demonstrated for the α-Fe 2 O 3 micro/nanostructure prepared under optimized conditions.