Template-free synthesis of hollow α-Fe₂O₃microcubes for advanced lithium-ion batteries

Abstract

Hollow α-Fe2O3 microcubes were fabricated by a facile hydrothermal method in an ethanol–water co-solvent system. The as-synthesized microcubes have a uniform size with an edge length of about 1.5 μm. Time and solvent proportion dependent experiments reveal that the ethanol adsorption and surface-protected etching mechanisms play key roles in the formation hollow cubic structures. Compared with their solid counterparts, hollow α-Fe2O3 microcubes show an enhanced electrochemical performance in terms of long-term cycling (458 mA h g−1 at a current density of 100 mA g−1 after 100 cycles) and high rate capability (859, 855, 688 and 460 mA h g−1 at current densities of 100, 200, 500 and 1000 mA g−1, respectively). These remarkable electrochemical properties can be attributed to the unique hollow microstructure, which could retain structural stability, relieve stress and increase reaction areas.