A facile synthesis of Li2Fe1/3Mn1/3Ni1/3SiO4/C composites as cathode materials for lithium-ion batteries

The novel Li2Fe1/3Mn1/3Ni1/3SiO4/C has been successfully synthesized by a feasible solution process in ternary system. The spherical carbon-coated composites are obtained using a heat treatment in the presence of sucrose. X-ray diffraction (XRD) diffractogram displays that the Li2Fe1/3Mn1/3Ni1/3SiO4/C crystallized in an orthorhombic structure with a space group of Pmn21. The energy-dispersive X-ray spectroscopy mappings indicate that Fe, Mn and Ni elements are distributed homogenously in Li2Fe1/3Mn1/3Ni1/3SiO4/C nano-spherical particle with size less than 50 nm. The lithium storage capacity and cycling performance of the Li2Fe1/3Mn1/3Ni1/3SiO4/C presents good results when tested as cathode materials in lithium cells at room temperature. It delivers an initial discharge capacity of 181.4 mAh g−1 and a discharge capacity of 172.9 mAh g−1 after 20 cycles at 0.1C in the voltage range of 1.5-4.6V. Furthermore, it also exhibits an excellent rate capability with a capacity under different current densities of about 144.0 mAh g−1 (0.2 C), 117.9 mAh g−1 (0.5 C), 106.1 mAh g−1 (1 C), respectively and a good capacity cycling maintenance of 153.7 mAh g−1 after 60 cycles. Above results indicate that the spherical Li2Fe1/3Mn1/3Ni1/3SiO4/C becomes a very promising candidate for cathode material in lithium-ion batteries.