High rate performance of the composites of Li4Ti5O12aKetjen Black and Li4Ti5O12aKetjen Blackamulti-walled carbon nanotubes for Li-ion batteries

• Published in: Solid state ionics Vol. 233; pp. 1 - 6
• Main Authors: Chen, Shuli, Wu, Hongbin, Hu, Huachong, Mo, Yinghua, Yin, Jinling, Wang, Guiling, Cao, Dianxue, Zhang, Yiming, Yang, Baofeng, She, Peiliang
• Format: Journal Article
• Language: English
• Published: 21.02.2013
• Subjects: Asymmetry; Carbon; Carbon nanotubes; Diffraction; Discharge; Lithium-ion batteries; Particulate composites; Scanning electron microscopy
• ISSN: 0167-2738

Composites of Li4Ti5O12aKetjen Black (Li4Ti5O12aKB) and Li4Ti5O12aKetjen Blackamulti-walled carbon nanotubes (Li4Ti5O12aKBaMWCNTs) are prepared by a simple solution method. Their morphologies and structures are characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis. Their electrochemical properties are investigated by galvanostatic charge-discharge test. Li4Ti5O12 particles in Li4Ti5O12aKB and Li4Ti5O12aKBaMWCNT composite have a diameter of ca. 40a60 nm. The discharge specific capacity is 157 (0.1 C), 110 (20 C) and 93 (30 C) mAh g- 1 for Li4Ti5O12aKB composite, and 157 (0.1 C), 133 (20 C) and 105 (30 C) mAh g- 1 for Li4Ti5O12aKBaMWCNT composite. After 100 cycles at 5 C, the discharge capacity retention of Li4Ti5O12aKB and Li4Ti5O12aKBaMWCNTs is 94% and 96%, respectively. Li4Ti5O12 shows asymmetric behavior between charge and discharge. The excellent high rate performance of Li4Ti5O12aKB and Li4Ti5O12aKBaMWCNT composites can be attributed to the reduction of Li4Ti5O12 particle size and the improvement of electronic conductivity due to the uniform distribution of Li4Ti5O12 particles within the carbon matrix conductive network.