Axial compressive α-Fe_2O_3 microdisks prepared from CSS template for potential anode materials of lithium ion batteries

摘要

In this paper, α-Fe_2O_3 microdisks (~1.1μm in diameter, ~150nm in thickness) have been synthesized by a facile hydrothermal method using a novel NaNO_3-Na_2SO_4 crystal salts solution (CSS) containing CNTs fragments as template. Interestingly, the synthesized α-Fe_2O_3 microdisks exhibit a unique axial compressive property. The small-sized CNTs fragments in α-Fe_2O_3 microdisks could act as a robust framework for such assemblies and endow them the axial compressive property. Owing to the existence of CNTs fragments, the α-Fe_2O_3 microdisks are not easily destroyed. AFM results indicate that the α-Fe_2O_3 microdisks could be compressed to 10-50 times than the original thickness. Electrochemical studies show that the synthesized α-Fe_2O_3 microdisks exhibited good cyclic stability and rate performance. The α-Fe_2O_3 microdisks electrode delivers a reversible specific capacity of 632mAhg~(31) even at a high rate of 800mAg31. When returning to the initial rate of 100mAg~(31), the α-Fe_2O_3 microdisks electrode returns to a higher capacity (968mAhg~(31)). The unique axial compressive property of α-Fe_2O_3 microdisks endows that they could alleviate the pulverization and structural destruction of electrodes during the lithium ion insertion and extraction process.