The cause of a lithium-ion energy storage system explosion that killed two firemen in China earlier this year has proved inconclusive.
A report by Beijing Fire Station noted that cell quality, battery management, electrical topology, external dust storms, and even wire arrangement could have led to the fire.
The lithium–ion phosphate battery formed a 25MWh system connected to 1.4MW photovoltaic array used at a public electric vehicle charging station Beijing Gotion Full-Service, in Beijng.
The fire happened on 16 April, and took 47 fire trucks and 235 fire fighters from 15 local fire brigades to control the blaze. A sudden explosion happened in the early hours of the next morning, killing two fire fighters and injuring one.
The report into the fire can be found here.
The report noted: “The sudden explosion of the power station in the north area could be explained by the safety accident induction mechanism of lithium batteries, which is the thermal failure of the batteries in the extreme conditions when they were significantly affected by internal and external sources.
“Due to the limitation of accidental information, it is hard to determine the fire accident was initiated by the poor quality of the batteries or the overloading input to the batteries which exceeds the limitation of the batteries. Several possible reasons are proposed.”
The project was developed and operated by Beijing Fuweisi Oil & Gas Co and commissioned in 2019.
The batteries were supplied by Guoxuan High-Tech Co, with 225 single cells connected in parallel and then in series to form a string, then 18 strings were connected in parallel to construct a 720V and 189Ah battery module.
The report follows news that China is on the verge of banning the use of second-life lithium-ion batteries in large-scale energy storage systems (ESS) until a “breakthrough in battery consistency management technology and a sound power battery performance testing and evaluation system” is developed.
Last week, BEST reported how toxic fumes and smoke from a fire involving up to 100 tons of lithium-ion batteries prompted emergency services to evacuate up to 4,000 people in Illinois, US.
Firefighters battled for more than three days to bring the fire involving around 180,000 to 200,000 pounds of lithium batteries under control.