Using Process Safety Principles to Mitigate the Hazards of Battery Energy Storage Systems

Lithium-ion batteries are increasingly being used in large-scale energy storage systems. These Battery Energy Storage Systems (BESSs) present unique fire and explosion hazards due to the use of flammable electrolytes and the large stored energy density. Principles commonly used in the chemical process safety field can also be adapted to assess and mitigate the hazards of BESSs. In this work, we summarize methods that have been developed to characterize the self-heating and flammability properties of cells and batteries of varying scales. Measured properties include thermal runaway onset temperature, vent gas composition, heat release rate, maximum overpressure, rate of pressure rise, flammability limits, and limiting oxidant concentration. These properties are then used to design fire and explosion mitigation systems for BESS installations. Finally, Process Hazard Analysis (PHA) methodologies can be used to perform a Hazard Mitigation Analysis (HMA) required by the new NFPA 855 Standard for the Installation of Stationary Energy Storage systems.