Gas release rates and properties from Lithium Cobalt Oxide lithium ion battery arrays

Lithium-ion batteries are increasingly being used for residential, commercial, and utility scale energy storage applications, any of which could include hundreds or thousands of individual cells, depending on the capacity of the individual cell. Hazard mitigation for multi-cell batteries should rely on data on the rate of cell-to-cell failure (i.e., thermal runaway propagation) and the rate and composition of flammable gases vented during such failure events. To generate such critically important data, experiments were conducted in a 53.5 L pressure vessel to characterize the gas vented from Lithium Cobalt Oxide (LCO) lithium-ion batteries, including rate of gas release, total gas volume produced, and gas composition. Experiments were conducted at three different states of charge (SOC) for single cells and arrays of five and ten cells. Three cell capacities were studied (5 Ah, 10 Ah, and 18.5 Ah). The data presented on the rate of release of vented gas are a significant addition to the literature. This paper also identifies key differences between single cell and cell array testing. The data provided in this paper can be used to make better decisions for ventilation and other safety systems for lithium-ion battery deployments.