Lithium-ion batteries are becoming more and more predominant in society. Almost every cell phone, laptop and portable electronic device today is powered using a lithium-ion battery. Lithium-ion batteries are also found in power tools, e-bikes, e-scooters, drones, electric vehicles, energy storage systems, and even spacecraft. If it is rechargeable, the chances are it’s powered by a lithium-ion battery. The current push towards electrification will result in an increasing prevalence and reliance on this technology. Most of the lithium-ion batteries manufactured today are made in China, South Korea, and other Asian countries. However, there is a significant push to build more lithium-ion battery manufacturing facilities in North America and Europe. In fact, at the time of this writing, there are more than 30 ‘giga-factories’ under construction in North America and Europe.
The fire hazards associated with lithium-ion batteries are well publicized. However, despite a clear recognition of the hazards associated with them, to date very little sprinklered large scale fire testing has been conducted to develop appropriate fire protection strategies when present in significant quantities (e.g., storage, manufacturing, etc.).
This presentation will begin with the fundamental hazards associated with lithium-ion batteries. It will discuss the publicly available large-scale fire testing of lithium-ion batteries conducted to date. It will then describe a recent project wherein a unique fire sprinkler protection scheme was tested at UL Solutions to assess its ability to mitigate cell-to-cell thermal runaway propagation in small format lithium-ion batteries at 100 percent state of charge within a rack-storage configuration. The test involved approximately 8000 cylindrical cells (18650 form factor) in polypropylene trays. The array of cells was forced into thermal runaway and the performance of the sprinkler protection scheme was assessed.