Fire characteristics of lithium batteries

With the rapid growth of lithium (ion) battery applications, the risk of fire is also flooded throughout its life cycle. From manufacturing, logistics, warehousing, to end users, we should be more aware that this tool not only provides energy, but also brings fire risks. Responsible measures should be taken to ensure safety at every link in the battery supply chain.

      Lithium batteries can ignite spontaneously and then explode due to overheating. Causes of overheating include electrical shorts, rapid discharges, overcharges, manufacturing defects, poor design or mechanical damage, and more. Overheating will lead to the "thermal runaway" process, that is, the exothermic reaction inside the battery will cause the internal temperature and pressure of the battery to rise at a rapid rate, thereby wasting energy.

      Once a battery cell enters a thermal runaway state, it generates enough heat to cause adjacent battery cells to also enter a thermal runaway state. As each battery cell ruptures in turn and releases its contents, a repetitive flame is created. This causes the flammable electrolyte in the battery to leak, and if a disposable lithium battery is used, it will also release combustible lithium metal. Then there will be a huge problem. These fires cannot be treated like "normal" fires, and targeted training, prevention and control planning, reasonable storage and establishment of fire suppression systems are needed.

      Data on the fire characteristics of large batteries are currently limited. However, we can predict that when the battery enters thermal runaway, thermal runaway propagation will produce identifiable marks; the battery will also show corresponding characteristics in some way. The fire may gradually burn out or explode. Both types of accidents, as well as the negative by-products they produce (sprayed shrapnel, molten metal, burning electrolytes, and other substances, etc.) can be managed and controlled by setting appropriate storage measures and transportation environments for the battery.

      Lithium (ion) battery-based systems may need to continue to use and develop some suppression and fire suppression systems to reduce the chance of negative accidents, thereby controlling risks, so that the battery system can be assured for users.

      Lithium (ion) battery fire accidents occur from time to time around the world. These fires have occurred in energy storage systems (wind, solar, etc.), battery test environments, transportation and storage, and many other areas. Many electric vehicles have experienced spontaneous battery pack fires, many of which involved fires or explosions. Although in the automotive, fire research, and emergency response industries, many people believe that the fire risk of lithium battery-powered vehicles will not be greater than that of conventional vehicle systems, it is widely recognized that by-products, heat, and flames caused by lithium battery fires can cause extreme fire Big danger. These hazards include its ability to release toxic substances and produce volatile combustion. In other words, compared to conventional fires, although lithium battery fires may not create "more" dangers, they are different from conventional fires and have unique hazards.

      Organizations that manufacture, transport, and store lithium (ion) batteries are also not considered immune from fire accidents. Thermal runaway incidents have also caused some large-scale fires in many facilities that store lithium (ion) batteries. These fires have a particularly large impact because the large number of lithium (ion) batteries usually stored in these facilities will further accelerate the spread of the fire.