LG Chem Contests Reasons for Battery FireBy Cas Biekmann | Fri, 08/28/2020 - 09:19
LG Chem, the manufacturer that provided the batteries involved in last year’s grid storage fire in Arizona, is reported by GreenTech Media to have a different vision as to what caused the incident that led to an explosion. The project’s owner, Arizona Public Service (APS), concluded that a defective cell triggered a chain reaction.
APS presented a report to legislators after working together with DNV GL. The analysis included novel safety measures that could prevent dangerous situations for other battery storage facilities, relevant for Mexico’s burgeoning storage market as well. The fire at the McMicken facility in April 2019 was caused by a battery container that caught fire, argues APS. First-responders tried to open the door, which caused an explosion causing injuries to several workers. Fortunately, the fire itself did not spread out. Nonetheless, a built-in aerosol fire suppressant was unable to stop the release of explosive gasses and the explosion occurred.
LG Chem has now published a report in conjunction with Exponent, an investigation firm, which outlines a different vision of the incident. Rather than internal flaws being the cause, LG Chem argues that external factors were ultimately the cause. If this is indeed the case, it would rule out the possibility that the batteries had been damaged somehow during the manufacturing process. The wreckage, however, made research considerably more challenging. Nonetheless, LG Chem argues that the proposed cell failure could also have been caused by heating from an external source, which APS’ report did not consider. “It is impossible for a non-conductive deposit to establish an internal cell short circuit, carry current, resistively heat and cause thermal runaway,” according to Exponent’s report. While both reports struggle to piece together the limited data, the real reason might be obscured forever.
Nonetheless, both reports note that some of the real damage stemmed from the integration of a thermal runaway, as well as a build-up of explosive gas which was not vented out. Therefore, previously issued safety measures proposed by APS would still enhance safety.
Regardless, in the following decade, findings for lithium-ion batteries might well prove to be irrelevant: WoodMac predicts that a new, different battery chemistry will become the most popular for stationary energy storage. As the market begins to split between batteries used for electric vehicles and stationary storage, lithium-iron-phosphate (LFP) is to take the top spot when it comes to the latter by the year 2030.