In this paper, we report on the facile preparation of porous Li2FeSiO4/C nanocomposites by tartaric acid-assisted sol–gel method and their electrochemical properties as the cathode materials of Li-ion batteries. The structure, morphology, and texture of the as-prepared samples are characterized by means of XRD, Raman, SEM, TEM/HRTEM, and N2 adsorption/desorption techniques. The results show that the porous Li2FeSiO4/C nanocomposites are consisted of nanoparticles, which have been coated with in situ carbon on the surface. The electrochemical properties of the as-prepared Li2FeSiO4/C nanocomposites have been investigated using galvanostatic charge/discharge and cyclic voltammograms. It is found that porous Li2FeSiO4/C nanocomposite with 8.06wt% carbon shows a high capacity of 176.8mAhg−1 at 0.5C in the first cycle and a reversible capacity of 132.1mAhg−1 at 1C (1C=160mAg−1) in the 50th cycle. This high capacity indicates that more than one electron reaction may be occurred. These results illustrate that the porous Li2FeSiO4/C nanocomposite with 8.06wt% carbon is potential in the application of high-rate cathode material of Li-ion batteries.