Tetragonal hematite single crystals as anode materials for high performance lithium ion batteries

Abstract

Understanding the correlation between the desired morphology of nanostructures and its electrochemical properties is a prerequisite for widespread application of advanced energy materials. Herein, two types of tetragonal α-Fe2O3 single crystals with a mean size of ca. 200 nm, including cubic and thorhombic shapes, have been synthesized via a facile hydrothermal approach. The as-obtained shape of α-Fe2O3 nanocrystals depends on the addition of the metal ions precursor, the Zn2+ ions result in the cubic shape and the Cu2+ ions result in the thorhombic shape, respectively. These two different tetragonal α-Fe2O3 single crystals are used as anode materials for lithium ion batteries (LIBs), and the results reveal that cubic α-Fe2O3 single crystal exhibits a better performance than thorhombic α-Fe2O3 single crystal. The discharge capacity of cubic α-Fe2O3 single crystal is up to 1028 mAh/g, and the current density is up to 1000 mA/g (1C) after 222 cycles. Clearly, the α-Fe2O3 single crystal with controlled shapes would improve the electrochemical performance of LIBs as superior anode materials, and this approach could pave a way to develop high performance LIBs.