Fire protection design of a lithium-ion battery warehouse based on numerical simulation results

Due to its instability and thermal runaway, a lithium-ion battery (LIB) has always been at severe risk in the process of transportation and storage. Recently, numerous studies have been conducted on the risk of thermal runaway in LIB storage, but most of them have focused on small-scale micro mechanisms. However, there has still been a lack of research on the risk of thermal runaway in large-scale scenarios, such as LIB factories and warehouses. In this study, the fire dynamics software (FDS) is used to simulate different fire conditions in a LIB warehouse numerically and determine the optimal battery state of charge (SOC), shelf spacing, and warehouse layout scheme of fire extinguishing facilities. The results show that when 50%- and 100%-SOC batteries are stored in a warehouse, the risk of thermal runaway fire spread and smoke diffusion is much higher than that under the zero-SOC condition. The results also indicate that an automatic fire-fighting water spray system has an obvious inhibitory effect on the fire in a LIB warehouse, and under the 100%-SOC condition, an automatic water sprinkler device with a quick-response sprinkler should be installed. The shelf spacing in a warehouse is also an important factor affecting the fire spread in a warehouse. Therefore, to prevent the spread of fire, a critical value of shelf spacing under different working conditions is defined, that is, when there is no automatic water sprinkler system under the 100%-SOC condition, the critical value of shelf spacing is 8.3 m, which is not economically practical. Therefore, when a warehouse stores lithium-ion batteries (LIBs) with medium and high SOC values, an automatic water sprinkler system should be set to reduce the critical value of shelf spacing.