The fire that broke out at Aricell’s battery manufacturing factory in Hwaseong, South Korea, on June 24. has raised concerns about the dangers associated with lithium batteries. Firefighters initially struggled to extinguish the blaze, and it was only after all 35,000 lithium-ion batteries in the factory exploded and burned out that full-scale firefighting efforts could begin.
Lithium batteries are widely used in smartphones, laptops, electric vehicles and military equipment. While these batteries are generally safe during normal use, they pose fire risks when overcharged, short-circuited, or damaged because they are sensitive to high temperatures and inherently flammable. Once lithium batteries catch fire, it is hard to put out, causing considerable damage as seen in the tragic Aricell factory fire.
Lithium batteries generate electricity through a chemical reaction involving lithium, the least dense metal under standard conditions. These batteries consist of an anode and cathode made of lithium and graphite, an electrolyte that serves as a pathway for electron movement, and a separator made of synthetic resin. Electricity is generated as electrons move between the anode and cathode, but the electrolyte, often composed of volatile solvents, makes the batteries particularly prone to fire or explosion.
Aricell manufactures primary lithium batteries, which cannot be charged. The lithium batteries used in everyday life, such as smartphones and laptops, are secondary lithium batteries, which are portable and rechargeable.
Non-rechargeable primary batteries tend to be more susceptible to catching fire. Primary batteries use lithium metal as the anode, which can cause a reaction close to explosion when it contacts water or moisture. Since these products are manufactured in a fully charged state, the damage is greater in the event of a fire. Aricell manufactures lithium thionyl chloride (LiSOCL2) cells, which produce toxic substances such as hydrogen chloride and sulfur dioxide when they react with water. At high temperatures, they can produce chlorine, making them particularly dangerous.
Despite the potential hazards, lithium batteries are integral to modern life due to their high energy density and long cycle life.
South Korea’s battery giants, including LG Energy Solutions, Samsung SDI, and SK On are working on enhancing battery safety. They are implementing the ‘Z-stacking method’ to tightly stack separators, and reduce the risk of damage. Battery makers are also coating the separators with ceramics to strengthen them and using new materials, such as carbon nanotubes, to prevent the volume expansion of anode and cathode materials.
Battery makers are researching and developing next-generation all-solid-state batteries that are expected to significantly reduce the risk of inflammation. These batteries replace the liquid electrolyte with a solid one, eliminating the need for a separator. Even in the event of an external shock, the solid electrolyte prevents direct contact between the anode and cathode, greatly reducing the likelihood of a short circuit.
At least 23 people were killed in a devastating fire at Aricell’s manufacturing plant on the morning of June 24. The fire reportedly broke out around 10:31 a.m. after a lithium battery combustion ignited a massive fire, but what triggered the explosion remains unclear. Among the dead, 5 were Korean and 18 were foreigners, officials said.
