More on methods to measure the energetics of lithium ion batteries in thermal runaway

Abstract

Experiments have been conducted on a variety of lithium ion batteries to measure their energy output in thermal runaway. Techniques were developed to measure the internal energy release as decomposition of the battery takes place, and combustion energy that can arise from ignited battery gases released in runaway. A nitrogen bomb calorimeter was designed, constructed and utilized to measure the internal energy in runaway. Three techniques were examined for measuring the combustion energy: (1) the Cone Calorimeter, (2) the Oxygen Bomb, and (3) the using a Gas Chromatograph to measure combustion species. The results from these measurement techniques are discussed and compared to the literature for similar batteries. Results generally show for 18650 batteries that the energies in runaway depend on chemistry, decomposition tends to increase with the SOC and can exceed its electric energy by 2-times, while combustion energy can reach 6-times.