Constructing of hierarchical yolk-shell structure Li_4Ti_5O_(12)-SnO_2 composites for high rate lithium ion batteries

摘要

High performance Li-ion batteries require materials with well-designed and controlled structures on nano and micrometre scales, and electrochemical properties can be enhanced by manipulating structure and morphology. Here a hierarchical yolk-shell structure Li4Ti5O12-SnO2 (LTO-SnO2) composites for application of lithium-ion batteries are successfully prepared by controlling the reaction temperature of hydrothermal process. The experimental results demonstrate that the LTO-SnO2 composites prepared at 130 degrees C (Marked as LS-130) have a well hierarchical yolk-shell structure and a good electrochemical property. The LS-130 electrode exhibits the first discharge specific capacity of 556.4 mAh g(-1) at 1 C, and a stable capacity of 253.2 mAh g(-1) still maintained even after 200 cycles. Moreover, when the current rate increase to 10 C, the average discharge specific capacities of LS-130 electrode also show 154.6 mAh g(-1), indicating an excellent rate performance. The excellent electrochemical performance is mainly ascribed to the stability of unique yolk-shell structure and composition involved with the numerous ultrathin LTO nanosheets. The work described here shows that the hierarchical yolk-shell structure LTO-SnO2 composite is a promising anode material for high power and long life lithium ion batteries. (C) 2018 Elsevier B.V. All rights reserved.