Improving electrochemical properties of spinel lithium titanate by incorporation of titanium nitride via high-energy ball-milling

Li4Ti5O12/TiN nanocomposites are fabricated through high-energy ball-milling of the mixture of spinel lithium titanate and TiN powder with different mass ratios of 100:1, 100:2, 100:4, and 100:8 (resultant nanocomposites are denoted as LTO–TiN-1B, LTO–TiN-2B, LTO–TiN-4B, and LTO–TiN-8B). All ball-milled samples exhibit markedly improved electrochemical properties than pristine Li4Ti5O12. Particularly, LTO–TiN-2B electrode has a high capacity of 130 mA h g−1 at a charge/discharge rate of 20C and the capacity retention was 85% after 1000 cycles at 10C, showing the best electrochemical performance and great potential as an anode material for high-rate lithium-ion batteries. The transmission electron microscopy and X-ray diffraction results indicate that amorphous TiN is generated on the surface of LTO. The improved electrochemical performance may be attributed to TiN which can significantly enhance the electronic conductivity of the nanocomposites.

► Li4Ti5O12/TiN nanocomposites were fabricated through high-energy ball-milling. ► Improved electrical conductivity by amorphous TiN conducting layer. ► Superior rate capability and cyclability for Li4Ti5O12 anodes.