November 11, 2021

Managing UL9540A Using Intumescent Composite Thermal Barrier Design

PyroPhobic Systems, Ltd.

This is a guest blog post from PyroPhobic Systems. Connect with PyroPhobic Systems at #ESACon21 in Phoenix, AZ, December 1-3. Registration is open!

PyroPhobic Systems Ltd. recently achieved a major product validation milestone using its proprietary Lithium Prevent fire-resistant intumescent composite as part of a battery energy storage system (BESS) design to contain thermal runaway lithium-ion battery fire events during UL 9540A full installation testing. The test was developed and performed by Energy Safety Response Group (ESRG), a global energy safety testing and risk management firm specializing in lithium-ion energy storage systems.

Lithium Prevent is an intumescent composite solution that is proven to contain runaway lithium-ion battery fire events, mitigating propagation. Lithium Prevent reacts to the heat of such a fire event by intumescing, creating an endothermic reaction that provides thermal separation between lithium-ion battery cells and/or modules actively on fire, thereby thermally separating adjacent cells/modules from the cascading event. Deep-seated thermal runaway events are not always easily accessible to active suppression and fire fighting hose stream water or to gas suppression systems. Panels of Lithium Prevent are integrated deep within the battery between cells and modules to provide thermal separation, preventing propagation and fire spread. Appropriately designed BESS systems have achieved superb results based on UL 9540A testing programs.

Building and fire codes throughout the US require fire protection from the risk of lithium-ion battery fire events. NFPA 855 references UL 9540A, a test method for evaluating thermal runaway fire propagation in battery energy storage systems.

Lithium Prevent passive fire containment barriers are used to achieve containment at the module and unit level. Lithium Prevent demonstrates the capacity to control propagation and prevent cascading thermal events, which in turn involves fewer cells resulting in less heat, and less vented hazardous gas. Based on these favourable outcomes, authorities having jurisdiction can waive the requirement to provide three feet separation between racks – a system modification that impacts the need for oversized ventilation and active fire suppression systems and affords the BESS designer greater energy density in a given footprint. In addition, through collaboration with authorities having jurisdiction, Lithium Prevent can unlock development and operating efficiencies by reducing or eliminating the reliance on water or gas suppression.

UL 9540A testing occurs at 4 different levels; beginning at the cell level, progressing to the module level, then advancing to the unit level and finally if required, then testing at the installation level. If fire propagation and deflagration hazards are not demonstrated by the test, fire code review and installation requirements are modified. Fire protection of the installation is matched to the fire performance of the BESS.

PyroPhobic Systems manufactures a range of intumescent composite technologies and routinely collaborates with equipment manufacturers working with accredited testing facilities to obtain code compliance in accordance with specific industry testing standards and regulations. With a focus on the renewable energy sector, PyroPhobic reduces the risk that lithium-ion battery fires pose to energy storage systems, contributing to the reduction of risk to first responders, and the health and safety of green energy infrastructure.

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