Carbon modified Li2Ti3O7 ramsdellite electrode for Li-ion batteries

An original carbothermal synthesis of ramsdellites phases under specific atmosphere (Ar, Ar/H2, N2, N2/H2) allowed creating in situ composites which showed good electrochemical properties as negative active materials of Li-ion batteries. The combination of chemical, XRD and electrochemical analyses enabled to identify the as-formed composite electrodes. It consists in ramsdellite/spinel for the synthesis under Ar/H2, TiO2 ramsdellite/Li2TiO3 for the synthesis under N2/H2, and Li2±xTi3O7/Li2±x′Ti3O7 for the samples prepared under both N2 and Ar. Carbon is partially inserted inside channels of titanate structure for the sample obtained under Ar/H2. For the first time, one of these composites allowed reaching a specific capacity close to the theoretical value of 198 mAh g−1.