Safety influences of the Al and Ti elements modified LiCoO2 materials on LiCoO2/graphite batteries under the abusive conditions

Under the abusive conditions, it is demonstrated that the thermal stability of LiCoO 2 and the safety of LiCoO 2 /graphite batteries are improved by doping and coating Al and Ti elements into the bulk structure and surface of LiCoO 2 . The trickle charge and the differential scanning calorimeter (DSC) results show that after coating Al and Ti oxides on the doped LiCoO 2 with 2000 ppm Al, the exothermic peak shifts to a higher temperature and the exotherm decreases, resulting in the increase of the thermal stability of LiCoO 2 . In addition, compared to the LiCoO 2 without Al doping, it is also indicated that the thermal stability of LiCoO 2 can be enhanced by doping Al, the exothermic peak of the LiCoO 2 with Al doping amount of 10000 ppm is up to 250 °C. Under the abusive testing conditions including thermal shock and overcharge, the safety evaluation results of pouch polymer LiCoO 2 /graphite batteries are in good agreement with the trickle charge and DSC results. These results reveal that the thermal stability of LiCoO 2 can be used as an indicator to evaluate the safety characteristics of LiCoO 2 /graphite batteries, and especially the introduction of Al and Ti into LiCoO 2 can effectively improve the safety of LiCoO 2 /graphite batteries under the abusive conditions.