Electrochemical properties of Si/LiTi2O2 nanocomposite as anode materials for Li-ion secondary batteries

Si/LiTi2O4 nanocomposite film was synthesized by a sol-gel method in combination with a following heat-treatment process. Through this process, the nanosized Si particles were homogeneously distributed in the porous composite. The electrochemically less active LiTi2O4 working as a buffer matrix successfully prevented Si from cracking/crumbling during the charging/discharging process. The Si/LiTi2O4 nanocomposite exhibited a reversible lithium storage capacity of about 1100 mA h g(-1) with good cyclability, suggesting its promising nature in anode materials for Li ion batteries. A two-parallel diffusion path model fitted well with the impedance data of porous Si/LiTi2O4 composite at different potentials. The impedance in the low-frequency region was directly related to the diffusion of Li ions, and the Li ion diffusivity was on the order of 10(-13) cm(2) s(-1) based on the semi-infinite diffusion model. (c) 2008 Elsevier B.V. All rights reserved.