Fabrication of N-doped carbon-coated Li4Ti5−xCoxO12 anode for lithium-ion batteries

Abstract

In this work, the Co2+-ion doping and N-doped carbon coating are adopted to improve the intrinsic and apparent electronic conductivities of Li4Ti5O12. This co-modified composite is fabricated through a ball-milling process followed by one-step solid-state reaction. XRD results demonstrate that the doped Co2+ does not destroy the spinel-type structure and it has successfully doped into the crystal structure of Li4Ti5O12. TEM images reveal that the surface of Li4Ti5-xCoxO12 particle is coated by a thin N-doped carbon layer with a thickness of 3–4 nm. Benefiting from the improved conductivity, the obtained composite displays an excellent rate capability and a stable cyclic property. Thus, the Co2+-ion doped and N-doped carbon-coated Li4Ti5O12 anode has great potential for the application of lithium-ion batteries.