Safety Insight of Li(Ni0.5Co0.2Mn0.3)O2 Based Lithium Ion Batteries with Gel Electrolyte
International Journal of Electrochemical Science
Safety is a crucial issue for large format lithium ion batteries. In this study, an attempt of thermal analysis is tried to know why the gel electrolyte is safer by understanding more about the thermal characteristics of the gel electrolyte battery and insight reason of safety enhancement. The extended volume-accelerating rate calorimetry (EV-ARC) is applied to evaluate the thermal stability of MCMB (mesoCarbon microBeads) | electrolyte | Li(Ni 0.5 Co 0.2 Mn 0.3 )O 2 batteries with gel
... s with gel electrolyte, and the battery with conventional electrolyte. The results indicate that the gel electrolyte delays the onset temperature of self-heating from 67°C to 135°C, and the onset temperature of thermal runaway from 195°C to 272°C, leading to large enhancement of the safety of the battery. The polymer of gel electrolyte shifts the temperature range of heat absorption from mainly before 180°C to higher temperature. The polymer from gel electrolyte can transform into a rigid film gradually during solvent evaporation, which prevents the polyolefin separator from shrinkage at temperatures below 225°C and thus avoids short circuit. This investigation demonstrates the confirmation of safety enhancement of gel electrolyte by thermal stability analysis. The gel electrolyte is a reasonable way towards safer LIBs.