关键词: 锂电池, 热失控抑制, 胺, 电解液, 开环聚合

Abstract:

The high energy density of NCM batteries with high nickel content is a key advantage in replacing fossil fuels and promoting clean energy development, at the same time, is also a fundamental cause of serious safety hazards in batteries. Primary and secondary amines can lead to ring-opening polymerization of common ethylene carbonate electrolytes, resulting in an isolation layer between the cathode and the anode, and improving the thermal safety of the battery. In this work, the safety of batteries is considered both at the material level and at the cell level, based on the chemical reactions between amines and the battery components. At the material level, the effect of the presence or absence of amine additives on the thermal stability of the different components of the lithium-ion battery was tested by differential scanning calorimetry. At the cell level, the safety of the whole battery with and without additives was tested by using accelerating rate calorimeter to extract thermal runaway (TR) characteristic temperatures. The addition of the amine resulted in an earlier onset of some of the chemical reactions between the battery components, as well as a significant reduction in total heat release and a decrease in the maximum temperature rise rate, such that TR, was effectively suppressed.

Key words: Lithium-ion batteries, Thermal runaway inhibition, Amine additive, Electrolyte, Polymerization reaction