Nanostructured cation disordered Li₂FeTiO₄/graphene composite as high capacity cathode for lithium-ion batteries

Nanostructured Li₂FeTiO₄/graphene composite with a cation disordered rock salt structure (Fm-3 m) has been synthesised via a solgel process using graphene oxide (GO) as a template. The as-prepared Li₂FeTiO₄ nanoparticles with a particle size of 20–50 nm are uniformly distributed on the graphene substrate. The Li₂FeTiO₄/graphene cathode shows phase transformations of Fe²⁺/Fe³⁺ and Fe³⁺/Fe⁴⁺ in a wide potential range from 1.5 to 5.0 V and possesses a high discharge capacity of 218.6 mAh g⁻¹ (equivalent to 1.4 Li per formula unit). A reversible capacity of 176.9 mAh g⁻¹ is maintained after 50 cycles. High capacity retention rate at 1C after 200 cycles is obtained. The Li₂FeTiO₄/graphene should be of great interest as a potential cathode material for high-performance lithium-ion batteries.