Solvothermal synthesis of monodisperse micro-nanostructure starfish-like porous LiFePO4 as cathode material for lithium-ion batteries

Abstract

A novel micro-nanostructured starfish-like LiFePO4/C with an open mesoporous structure is successfully synthesized via a solvothermal route with triethylamine. The structure and morphology of the samples are examined by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM). The electrochemical performance of the samples is characterized by charge–discharge tests and cyclic voltammetric (CV) measurement. The results show that the as-synthesized LiFePO4/C sample exhibits a monodisperse starfish-like morphology with a particle size of around 10 μm, open mesoporous structure with average pore diameters of 3.0 nm and high tap density of 1.34 g cm−3. Although the particles size is large upto micron scale, the sample displays excellent electrochemical performance due to its open mesoporous structure which is beneficial to the Li+ diffusion and electron transportation. Besides, it exhibits a specific capacity of 157.5 mAh g−1 at 1 C, even the discharge rate increases to 20 C, it still exhibits a high initial discharge capacity of 86.7 mAh g−1.