Abstract
Lithium-ion batteries are increasingly adopted in stationary applications such as uninterruptible power supply (UPS) systems, introducing complex fire safety challenges, particularly in confined and heritage-sensitive environments. One of the most critical hazards is thermal runaway, a self-sustaining electrochemical failure process capable of releasing, in a very short time, large amounts of energy, flammable gases, and toxic by-products, with potential cascading propagation between adjacent cells. This study presents a performance-based fire engineering assessment of a nitrogen inert gas suppression system designed to protect a basement technical compartment within a historic Venetian villa. A lithium-ion battery runaway scenario with cascading potential is analysed through computational fluid dynamics (CFD) modelling; input parameters and modelling assumptions are derived from institutional and experimental literature and the effectiveness of early nitrogen inertization in preventing ignition and arresting runaway propagation is evaluated. Results confirm that oxygen depletion represents an effective mitigation strategy for confined lithium-ion battery installations where conventional water-based systems show significant limitations.
