Solid-state synthesis and electrochemical performance of Li4Ti5O12/graphene composite for lithium-ion batteries

•Homogeneous Li4Ti5O12/graphene composite is prepared via an in situ solid state reaction with the help of carbon pre-coating.•Carbon coating confines agglomeration of the Li4Ti5O12 particle and enhances the combination between Li4Ti5O12 particles and graphene sheets.•The homogeneous Li4Ti5O12/graphene composite delivers a quite high capacity of about 136mAhg−1 at 120C. Homogeneous Li4Ti5O12/graphene composite is prepared via an in-situ solid state reaction, after carbon pre-coating has been carried out. Its microstructure is compared with the materials prepared by a similar way, but without carbon coating. The results reveal that the carbon coating not only effectively confines aggregation and agglomeration of the Li4Ti5O12 particles, but also enhances the combination between Li4Ti5O12 particles and graphene sheets. The Li4Ti5O12/graphene composite presents excellent rate capability and low-temperature performance. Even at 120C, it still delivers a quite high capacity of about 136mAhg−1. When the charge–discharge tests are performed at −10°C and −20°C, its specific capacities are as high as 149 and 102mAhg−1, respectively. In addition, the full-cells using LiNi1/3Co1/3Mn1/3O2 as cathode material exhibit good rate capability.