A porous Li2FeSiO4/C composite is synthesized via a hydrothermal-assisted sol-gel method. The porous Li2FeSiO4/C composite consisted of nanoparticles with only 20-30 nm size, surrounded by a nitrogen-doped carbon coating layer. Hydrothermal treatment plays a key role to control the crystallite size of the Li2FeSiO4 particles and to form the porous structure. The Li2FeSiO4/C composite obtained via a hydrothermal treatment exhibited a large surface area (50.2 m(2). g(-1)), which not only effectively prevents the agglomeration of Li2FeSiO4 particles, but also facilitates fast electron and Li+ transport More than 1 mol Li+ can be extracted from the Li2FeSiO4/C electrode, which exhibits excellent electrochemical performance with a high discharge capacity of 195.5 mAh.g(-1) at 0.1 C and 127.1 mAh.g(-1) at 5 C (1 C = 166 mA.g(-1)). These results illustrate that the porous Li2FeSiO4/C composite is a promising cathode material for lithium ion batteries. (C) 2015 Elsevier B.V. All rights reserved.