Synthesis of Li2FeSiO4/C nanocomposite via a hydrothermal-assisted sol–gel process

Abstract A porous Li 2 FeSiO 4 /C composite is synthesized via a hydrothermal-assisted sol–gel method. The porous Li 2 FeSiO 4 /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 Li 2 FeSiO 4 particles and to form the porous structure. The Li 2 FeSiO 4 /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 Li 2 FeSiO 4 particles, but also facilitates fast electron and Li + transport. More than 1 mol Li + can be extracted from the Li 2 FeSiO 4 /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 Li 2 FeSiO 4 /C composite is a promising cathode material for lithium ion batteries.