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

Abstract

A porous Li2FeSiO4/C composite is synthesized via a hydrothermal-assisted sol–gel method. The porous Li2FeSiO4/C composite consisted of nanoparticles with only 20–30nm 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 (50.2m2·g−1), which not only effectively prevents the agglomeration of Li2FeSiO4 particles, but also facilitates fast electron and Li+ transport.More than 1mol Li+ can be extracted from the Li2FeSiO4/C electrode, which exhibits excellent electrochemical performance with a high discharge capacity of 195.5mAh·g−1 at 0.1C and 127.1mAh·g−1 at 5C (1C=166mA·g−1). These results illustrate that the porous Li2FeSiO4/C composite is a promising cathode material for lithium ion batteries.