Enhancement of Electrochemical Performance of Li4Ti5O12/C Composite Prepared by Sol-Gel Method
Phase pure Li4Ti5O12/C composite was synthesized by sol-gel method using lithium acetate CH3COOLi•2H2O and tetrabutyl titanate [Ti(OC4H9)4] as starting materials, oxalic acid as chelating agent and sucrose as an additional carbon source. The as-prepared samples were characterized by means of TG-DTA, XRD and SEM. The electrochemical properties were investigated in terms of constant-current charge/discharge cycling and high-rate dischargeability. SEM analysis indicated that the prepared Li4Ti5O12/C composite using sucrose and oxalic acid as carbon source showed a spongy nano-particle aggregate structure, with average nano-particle size of 80-100 nm. Electrochemical results showed that the Li4Ti5O12/C composite prepared in the presence of sucrose exhibited better electrochemical performance with specific discharge capacities of 204.7, 171.6, 155.3 and 154.6 mAh/g at 0.2C, 1C, 2C, and 5C rates, respectively. And the discharge capacity could still reach 143.9mAh/g after 80 cycles at 1C rate, exhibiting excellent cycling performance.
Jinsheng Liang and Lijuan Wang
L. Wang et al., "Enhancement of Electrochemical Performance of Li4Ti5O12/C Composite Prepared by Sol-Gel Method", Advanced Materials Research, Vol. 178, pp. 143-150, 2011