Effect of carbon nanotubes addition on electrochemical performance and thermal stability of Li_4Ti_5O_(12) anode in commercial Li Mn_2O_4/Li_4Ti_5O_(12) full-cell

摘要

Li_4Ti_5O_(12)(LTO)/carbon nanotubes(CNTs) composite material is synthesized based on a solid-state method by sand-milling, spray-drying and calcining at 850 8C under N2 flow. The LTO/CNTs samples with1 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 Li Mn_2O_4(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.