Improving the Electrochemical Performance of Li 4 Ti 5 O 12 Anode through Confinement into Ordered Bimodal Porous Carbon Frameworks

Li 4 Ti 5 O 12 (LTO) was confined into bimodal mesoporous carbon (BMC) framework, and the confinement effects of BMC on the crystal structure and electrochemical performances of LTO were comprehensively investigated by means of X-ray diffraction, small-angle X-ray spectroscopy, Brunaer–Emmett–Teller analysis, transmission electron microscopy, and electrochemical analysis for the first time. In comparison to bulk Li 4 Ti 5 O 12 the rate capability and the cycling performance of Li 4 Ti 5 O 12 confined in BMC (Li 4 Ti 5 O 12 @BMC) were largely improved. The rate capability of Li 4 Ti 5 O 12 @BMC was enhanced about 50 mA·h/g at each current rate. Li 4 Ti 5 O 12 @BMC showed a good cycling performance (about 245 mA·h/g at 0.5 C and 165 mA·h/g at 10 C) and high Coulombic efficiency. The enhanced properties can be attributed to the confinement effect of the hierarchical porous carbon which offered much more electrode/electrolyte interface owing to the large surface area, favored the Li + and electron transportation due to the hierarchical bimodal pore structure, shortened the diffusion path of both Li ions and electrons, avoided the particle aggregation, and increased the conductivity of the matrix.