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Safety study of three types of lithium ion batteries

Safety is the first priority of any energy storage system. In this paper, safety studies are performed on three types of 2.6 Ah lithium ion batteries: high-drain thin-electrode battery (Cell 1), cellphone battery (Cell 2) and 18650 type battery (Cell 3), which are different in geometry and internal parameters. The batteries' discharge behaviors are tested on a battery analyzer, and their performances in nail penetration are simulated with an electrochemical-thermal coupling model. It is found that both the battery geometry and internal parameters have significant effects on the performance and safety of battery. Cell 1, with the lowest internal resistance among all, has the minimal temperature variations during discharges, but its simulated temperature rise in penetration is dramatic, especially at the nail point. As the internal resistance of battery increases, Cell 2 and Cell 3 experience severer temperature elevations and significant losses of available power and capacity at high-rate discharges, but meanwhile, they show better thermal behaviors in penetration simulation, with the maximum temperatures of both keeping below 200oC.