In this work, LiFePO4/C composites were prepared in hydrothermal system by using iron gluconate as iron source, and two feeding sequences during the preparation were comparatively studied. The morphology, crystal structure and charge–discharge performance of the prepared samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and galvanostatic charge–discharge testing. The results showed that the feeding sequences and iron gluconate seriously affected the microstructures and electrochemical properties of the resulting LiFePO4 cathodes in lithium ion batteries. The spindle-shaped LiFePO4 with hierarchical microporous structure self-assembled by nanoparticles has been successfully synthesized by synthesis route B. In addition, the cell performance of the synthesized LiFePO4 by synthesis route B was better than that of LiFePO4 by synthesis route A. Specially at high rates, the superior rate performance of the spindle-shaped LiFePO4/C microstructure (LFP/C-B) was revealed. And special reversible capacities of ∼118 and ∼95 mAh g−1 were obtained at rates of 2 C and 5 C, comparing to ∼96 and ∼68 mAh g−1 for LFP/C-A.Highlights► The spindle-shaped LiFePO4 with hierarchical microporous structure self-assembled by nanoparticles has been synthesized by synthesis route B. ► The feeding sequences and iron sources seriously affected the microstructures and electrochemical properties of the resulting LiFePO4 cathodes. ► The cell performances of the synthesized LiFePO4 by synthesis route B were superior to that of LiFePO4 by synthesis route A.