Fire Kills - Lithium-ion batteries video transcript

Lithium-ion batteries are increasingly used in our daily lives.

Lithium-ion batteries contain several cells each cell capable of storing large amounts of energy in a small space.

When used or charged these batteries produce heat. This heat is dissipated to the battery surroundings.

Lithium-ion batteries power all kinds of devices but if poorly made or used incorrectly, this can cause the battery to overheat resulting in an extreme and dangerous reaction called thermal Runaway.

Some examples of this misuse are:

• overcharging
• charging with an incompatible or non-compliant charger
• damage caused by a harsh impact
• or water entering the battery enclosure

Thermal runaway begins when the battery suffers some kind of abuse that causes the battery to rapidly release its stored energy in the form of heat.

When the heat generated by the battery exceeds its ability to dissipate the heat, the temperature within the battery starts to rise.

If the cause of excessive heat is not removed the internal battery temperature will continue to rise until it reaches the point that causes a chemical reaction to occur inside the battery.

This chemical reaction produces even more heat which drives the temperature higher.

The internal structure of the cell becomes unstable leading to breakdown and collapse. The rise in temperature in a single cell will begin to affect cells in close proximity creating a domino effect.

Thermal runaway is now spreading to the other cells. Once this exothermic reaction gets hold, even removing external sources that may have caused it will not prevent thermal runaway and a battery fire or explosion.

The temperature of the cell accelerates uncontrollably and can reach temperatures in excess of 700 degrees Celsius.

The total heat energy that can be released from the battery can exceed 10 times the amount of energy stored inside if all combustible materials react with air.

Any remaining energy within the cells residual energy rises in temperature and may reignite.

Thermal runaway also causes the release of toxic chemicals and gases. This can cause long-term damage to a person's health.

Thermal runaway has a huge impact on the surroundings of where it occurs. Fire and smoke can lead to damage and loss of life.

If you find yourself in a situation where thermal runaway is happening, especially in an enclosed space, warn others, get out and call the fire service.

For more information visit, electricalsafetyfirst.org.uk