Fenggang Battery Factory Battery Fire Truth

The problem arises here. The workers do not understand the internal structure of the lithium battery. It is ineffective to use the dry powder fire extinguisher after the battery is self-ignited. The best way is to use water to cool down.

For battery companies, the biggest danger is the manufacturing of internal short circuits.

——Shujun Li, Ph.D. in Physics, Graduated from Institute of High Energy Physics, Chinese Academy of Sciences

"Fenggang Town, a battery factory fire 5 women workers died" tracking

Why is the battery of Fenggang Battery Factory self-igniting? Yesterday afternoon, Dongguan Fire Department invited Shujun Li, a famous domestic lithium battery expert, to analyze the spontaneous combustion of the battery to find the chief culprit causing the fire. Shujun Li said that the internal short circuit is likely to cause a spontaneous combustion explosion. Shujun Li also pointed out that at present the country has no technical supervision standards for the production process of lithium-ion batteries, resulting in chaos in the industry. In recent years, Dongguan has poured into a large number of such battery manufacturers, and there are many hidden dangers.

"The battery is more likely to be internally shorted"

Shujun Li is a Ph.D. in physics graduated from the Institute of High Energy Physics of the Chinese Academy of Sciences. He is also one of the early researchers in the development of lithium-ion battery technology in China. In the face of the fire department investigation team, Shujun Li opened a lithium battery, only inside a layer of aluminum foil and copper foil, with a layer of plastic-like diaphragm in the middle. Shujun Li explained that during the processing of lithium-ion batteries, the pole pieces of the positive and negative electrodes are superimposed together, the separator is strictly separated in the middle, and then tightly wound together, placed in a pre-processed casing, and a liquid electrolyte is injected. And sealed the opening, a lithium battery is ready. At this time, the battery itself is not charged. Only the diaphragm and the electrolyte are flammable, but they are not flammable and are very safe. “There is no high-risk process in the entire process, and there are no special factors for fire and explosion.”

However, the battery will be charged, put on hold and tested before it leaves the factory. If there is a short circuit after charging, it will cause spontaneous combustion. "Short-circuit is divided into internal short-circuit and external short-circuit. The cause of external short-circuit may be caused by storage and transportation, and internal short-circuit is the problem of the product itself." Shujun Li further explained that these problems include: in the production process. The environment is unclean, causing the positive and negative electrodes to be contaminated with other substances; the internal diaphragm cannot effectively separate the positive and negative electrodes, and there are defects. This will cause the amount of electricity stored in the battery to be quickly released through the connection point, and a large amount of heat will be released instantaneously. The temperature of the battery will rise sharply first causing combustion of combustibles such as electrolyte and diaphragm. After the temperature rises to a certain extent, the positive and negative electrodes the substance and aluminum foil will also burn intensely, and the center temperature will rise above 1000 degrees Celsius, and a similar explosion will occur. If a large number of batteries are stored centrally inside the factory, it will cause a chain fire and explosion.

"Lithium batteries can't extinguish the fire with dry powder."

"After the Fenggang fire, I have been paying attention to it." Shujun Li said that he saw a detail from the media. One employee said that the battery was often spontaneously burned during the first charging session. Everyone was used to it, so they did not escape in time. Finally, using a dry powder fire extinguisher, but how can it not extinguish the fire. "The problem is here, because the workers do not understand the internal structure of the lithium battery, so the use of dry powder fire extinguishers after spontaneous combustion cannot work."

Shujun Li said that due to the internal combustion of the battery, the use of dry powder fire extinguishers will not work, and the best way is to use water to cool down.

Observed

Worry: lack of standards for lithium battery manufacturing

In recent years, there have been more and more self-ignition and even explosion accidents of batteries. Shujun Li said that the ultimate reason is that there are gaps in the production standards of enterprises in China, which has led to chaos in the industry. “External short circuit or improper use by consumers is rare, and it is easier to avoid due to improper stacking and transportation inside the factory. For battery companies, the biggest danger is the manufacturing flaws that cause internal short circuits,” Shujun Li said. For such defects, battery manufacturers need processing equipment with good precision and production in a low-humidity, low-dust environment, and complete monitoring and testing in each process.

At the same time, in order to avoid the self-ignition of the battery after charging, the uncharged battery must be stored separately in the fireproof compartment, and the monitoring facilities and automatic fire extinguishing devices such as smoke and spray should be installed, and the operator must leave the safe distance, there should be a smooth escape route nearby. "But due to the existence of low-end non-standard markets such as cottages and charging treasures, many small-scale battery factories use simple equipment to manufacture lithium-ion batteries, lacking the most basic quality control measures, and various internal products. There are many defects, and the hidden dangers of fire and explosion are extremely great. At the same time, the batteries after charging are piled up at random and the people and goods are adjacent, there is no fire safety measure and it is very prone to fire accidents and cause casualties.

The reason is that there is no technical supervision standard for the production process of lithium ion batteries. The relevant person in charge of the Dongguan Fire Bureau said that the number of battery companies moving from Shenzhen and other places to Dongguan has increased in recent years, and the specific number is still in statistics.

Related news

Secretary takes the lead in Fenggang pull net to check fire hazards

More than 100 employees in the battery factory received the salary, and Fenggang Town carried out a three-month investigation on fire safety hazards.

“I received the salary in October and November.” Yesterday morning, the relevant departments of Fenggang Town raised funds and distributed wages to more than 100 employees of the battery factory in the Anke Industrial Park. At the same time, Fenggang Town carried out a three-month investigation of fire safety hazards. The leaders of the town led the team to their respective villages and industrial parks to conduct comprehensive investigations on the safety hazards of the production and operation units and sub-tenant factories.

Yesterday morning, an employee of Dongguan JinMingyang Battery Technology Co., Ltd. said, “I thought it was difficult to pay wages according to the actual workload. I didn’t expect the salary I received today to be similar to my own calculation.” The interviewed employees said that the wages they received were roughly the same as the actual workload. According to the staff of the Fenggang Town Government Mission Office, a total of 670 employees were paid 670,000 Yuan on the same day. Some employees did not receive the salary on the spot.

After the "11.19" fire accident, Fenggang Town immediately launched a large-scale investigation and major rectification of fire safety hazards in the town. Fenggang Town, including the members of the leadership of the township committee, led the team to go deep into the villages and industrial areas of the town, pull the network to check and rectify fire safety hazards, and prevent similar accidents from happening again. It is understood that this fire safety hazard investigation and rectification campaign will last for three months. The hidden dangers discovered by the investigation will be rectified in a timely and resolute manner, and the rectification will be ordered. For enterprises that refuse to rectify, the town will take decisive measures and be listed and supervised rectification.

The page contains the contents of the machine translation.