Thermal runaway analysis and model of nickel-rich lithium-ion batteries in different overcharging states

Lithium-ion power batteries are favored for their light mass, high energy density and low pollution, but repeated thermal runaway accidents have prevented the large-scale use of lithium-ion power batteries. The thermal safety of lithium-ion batteries is also receiving increasing attention. In this paper, the thermal runaway characteristics of 18650 nickel-rich lithium-ion batteries triggered by heating in different overcharge states are investigated using an extended volume accelerated calorimeter $(\text{EV}+-\text{ARC})$. And the voltage data is collected. The battery's self-heating temperature was examined based on the experimental findings. The time required for the lithium-ion battery from safety valve opening to complete thermal runaway is compared. A thermal reaction kinetics TR model of the thermal runaway of Lithium-ion batteries is developed, and the model curves are in high agreement with the experimental curves.