Effect of carbon nanotubes addition on electrochemical performance and thermal stability of Li4Ti5O12 anode in commercial LiMn2O4/Li4Ti5O12 full-cell

Li4Ti5O12 (LTO)/carbon nanotubes (CNTs) composite material is synthesized based on a solid-state method by sand-milling, spray-drying and calcining at 850 °C under N2 flow. The LTO/CNTs samples with 1 wt% and 3 wt% weight ratio of CNTs addition and the pristine LTO sample are prepared. The rate performance and the thermal stability of these samples are investigated based on LiMn2O4 (LMO)/LTO full-cell. The results show that the weight ratio of CNTs addition has distinct effect on LTO performances. The composite materials of LTO composited CNTs have better performance at high-rate due to the intercalation enhancement by conductive network of CNTs. At second, the overcharging temperature response of the cell's surface with 1 wt% CNTs addition is the lowest. The particle size distribution is measured and the most uniform particles are obtained with 1 wt% CNTs addition. This trend could explain that the medium quantity of CNTs is optimal to improve the heat and mass transfer and prevent the problems of crystallite growing interference and aggregation during the calcination process.

This solid-state based synthesis route of LTO/CNTs composite materials is suitable for commercial production. Medium quantity of CNTs addition is optimal to improve the thermal stability of LMO/LTO full-cell, and excessive CNTs addition could interfere with the crystallite growing of LTO during calcination process.Figure optionsDownload as PowerPoint slide