Mixed-solvothermal synthesis and morphology-dependent electrochemical properties of α-Fe2O3 nanoparticles for lithium-ion batteries

A mixed-solvothermal method was used to synthesize the α-Fe 2 O 3 nanoparticles with nearly spherical, rod-like, disk-like morphologies by varying the precipitant or solvent. When used as the anode material for Li-ion batteries, the nearly spherical α-Fe 2 O 3 nanoparticles with a high monodispersity and an average diameter of about 50.5 nm exhibited much better cycle stability and rate performance than their disk-like and rod-like equivalents. Their reversible capacity reached up to 1500 mAh/g that far exceeded their theoretical value (1007 mAh/g) at a current density of 0.1 A/g. Even after 100 cycles, there was still a capability retention of about 1200 mAh/g. Moreover, the analysis of the Nyquist plots revealed that the nearly spherical α-Fe 2 O 3 nanoparticles presented the lowest charge-transfer resistance among the three samples. The present study provides an effective way to control the morphologies of nanoparticles, and these nanostructures would present great potentials for the applications in LIBs or some other fields.