Why firefighters struggled to put out the battery blaze

Fire accidents involving lithium batteries, like the one at Korean lithium battery manufacturer Aricell's facility, are challenging to extinguish due to the batteries’ potential for water to exacerbate the situation.

Primary, or single-use, lithium batteries differ from more commonly known lithium-ion batteries in several fundamental ways. They use lithium metal or lithium compounds as the anode and are ready-charged and non-rechargeable. While they do not suffer from issues like thermal runaway, which is typical in lithium-ion batteries, primary lithium batteries can still pose fire risks if physically damaged or overheated.

Fire incidents involving primary lithium batteries can occur due to a direct short circuit if the metallic lithium comes into contact with moisture, causing it to react and potentially ignite. Unlike lithium-ion batteries, primary lithium batteries do not emit flammable gases like hydrogen during typical failure scenarios, but they can release lithium fumes and other toxic substances if burned.

The challenges in extinguishing fires that involve lithium batteries stem from their ability to burn fiercely and to react with water. Therefore, the firefighters at the Aricell site initially focused on containing the blaze to prevent it from spreading to nearby factories. They surrounded the building in order to prevent the fire from reaching adjacent structures while waiting for the batteries to burn out completely.

However, later in the afternoon, it was revealed that the batteries in the factory contained only a small amount of lithium, and in solution rather than in a metallic state. As a result, the firefighters used water to extinguish the fire as they would with regular fires, and succeeded in completely extinguishing the blaze.

“The batteries at the factory used electrode material soaked in a lithium solution and layered into a structure similar to rolled paper, rather than traditional lithium powder. With about 5 kilograms of lithium in the solution compared to 200 kilograms of water, the risk of explosion was very low," said Na Yong-woon, a researcher at the National Fire Research Institute of Korea.

Aricell, a subsidiary of the Kosdaq-listed S Connect, occupies a three-story, reinforced concrete building with a total floor area exceeding 2,300 square meters. Established in May 2020, the factory employs around 50 workers and specializes in producing lithium primary batteries, particularly for smart meters used in smart grids. S Connect itself is known for manufacturing metal components for smartphones and other electronic devices.