Synergistic effect of TiO2 and TiN on the electrochemical performance of SiO as anodes for lithium ion battery

In order to investigate the synergistic effect of TiO2 and TiN on the electrochemical performance of SiO as anodes for lithium ion battery, a series of SiO/TiO2-TiN hybrid materials with different compositions are synthesized through simple high-energy mechanical ball milling using SiO, nano-TiO2 and nano-TiN as raw materials. Compared with TiO2 or TiN alone, the combination of TiO2 and TiN can significantly improve the utilization and cycle stability of SiO. Among them, the 65%SiO/35%(TiO2-TiN(8:2)) hybrid exhibits the best comprehensive electrochemical performance. Even at a relatively high mass loading and compaction density, the stable discharge capacity of the electrode is about 920 mAh g−1 at 100 mA g−1. At 500 mA g−1, the stable discharge capacity is kept at about 760 mAh g−1 until 250 cycles. When the current density increases to 1600 mA g−1, the stable capacity is still as high as 480 mAh g−1. The improved electrochemical performance is attributed to the synergistic effect of TiO2 and TiN in buffering the volume effect of Si and improving the conductivity of SiO. Different from the previous report, it is found that although the crystal structure of TiN is not destroyed during cycling, its initial reversible pseudocapacitance capacity reaches 80 mAh g−1 at 500 mA g−1.