Multiple phase N-doped TiO2 nanotubes/TiN/graphene nanocomposites for high rate lithium ion batteries at low temperature

It is extremely important to develop anode materials alternative to graphite at low temperature (below 0 degrees C) from the viewpoint of safety and capacity for lithium ion batteries. TiO2, as a promising anode material, has poor electronic conductivity and ionic conductivity, thus limiting its rate performance at low temperature. Herein, we have designed a novel multiple-phase composites composed of N-doped TiO2/TiN/graphene to improve the ionic conductivity and electronic conductivity and then ameliorate its electrochemical performance at low temperature. The as-prepared nanocomposites show excellent performance as anode in lithium ion batteries at low temperature (0, -10 and -20 degrees C). Even at - 20 degrees C, the optimized nanocomposites exhibit high reversible specific capacity (211 mAh g(-1) at 0.1 A g(-1)), excellent rate performance (150 mAh g(-1)at 1 A g(-1) ) and good cycling stability (similar to 93% within 500 cycles), indicating superior electrochemical performance at low temperature. Furthermore, the as-prepared nanocomposites are able to deliver similar to 154 mAh g(-1)at 20 A g(-1) at room temperature. Considering the intrinsic safety, excellent electrochemical performance and good adaptability at both low and room temperature, the prepared nanocomposites can have great potential in lithium ion batteries.