An experimental investigation on the burning behaviors of lithium ion batteries after different immersion times

The seawater immersion test is an important indicator of the lithium ion batteries (LIBs) safety, and the fire behavior of LIBs is affected by immersion time t(im). In this study, 3.5 wt% NaCl solution as surrogate seawater is used to perform LIBs immersion test. Several parameters are measured to evaluate the fire hazards of LIBs, such as ignition time t(ig), surface temperature, mass loss, heat release rate and total heat release. The fire hazards of batteries immersed under different t(im) is assessed by a conical calorimeter. The experimental results demonstrate that t(ig) reaches a minimum value when t(im) is 3 h, and t(ig) changes slightly with further increase of t(im). The heat release rate reaches a maximum value when t(im) is 3 h for 100% stages of charge (SOC), and 2 h for 50% SOC. The ejection temperature T-ej remains constant with the increase in t(im), while the maximum temperature T-max decreases with the increase in t(im). (c) 2019 Elsevier Ltd. All rights reserved.