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

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It is extremely important to develop anode materials alternative to graphite at low temperature (below 0 °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 °C). Even at −20 °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 (∼93% within 500 cycles), indicating superior electrochemical performance at low temperature. Furthermore, the as-prepared nanocomposites are able to deliver ∼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.