Synthesis and electrochemical properties of carbon nano-tubes modified spherical Li2FeSiO4 cathode material for lithium-ion batteries

A carbon nano-tubes (CNTs) modified spherical Li2FeSiO4 cathode material has been synthesized by a solid-state reaction method. The as-prepared Li2FeSiO4 composite has a micro-spherical morphology and is significantly constituted of a large number of nano-spheres connected by CNTs. Charge–discharge test shows that the sample exhibits discharge capacity of 153 mAh g−1 at 0.1 C rate in the voltage range of 1.5–4.6 V. When discharging at 10 C rate, the samples demonstrate a specific discharge capacity of 78 mAh g−1. Such an enhancement of the electrochemical properties has been ascribed to a reduction of the particle size, the network-like connection with CNTs and the porous micro-spherical morphology.

► The carbon nano-tubes modified spherical Li2FeSiO4 cathode material was synthesized.
► The synthesized micro-spheres contain large amount of nano-spherical primary particles.
► The nano-spherical primary particles were connected by coated carbon and carbon nano-tubes.
► The rate performance and cyclability of the material are pretty good.