Five questions about exploding batteries

It happened again this week. A power bank (in Dutch) in the back pocket of a traveler exploded in Melbourne Airport. The man caught fire but was quickly helped and put into a shower. Erik Kelder, a battery researcher, is not surprised.

Are lithium-ion batteries unsafe?

“Lithium-ion batteries in themselves are safe. It is about how they are handled. A power bank in a bag that is chucked somewhere, or an electric bicycle that accidentally falls over can cause internal damage. This in turn can lead to a short circuit whereby a lot of power suddenly surges through the battery, it gets extremely hot, and falls apart. Stored energy is not dangerous. A bottle of methylated spirits is one example. But if the methylated spirits is suddenly released and catches fire, you have a problem. Lithium-ion batteries can store three times more energy than car batteries. In their case the whole process goes very fast as they contain liquid that will also catch fire and emit hazardous gases.”

Is the number of incidents with lithium-ion batteries rising?

“Yes, but this more related to the exponential increase in usage of the batteries – for electric bicycles, electric cars, laptops, telephones and so on – than that the batteries in themselves are less safe.”

What should you do in case of a lithium-ion fire?

“Do not put it out with water, that only makes it worse. Put it out with CO₂ which cools the device. Then you can move it to an isolated place and let it burn itself out safely. If it’s a small battery, such as in your phone, you can also immerse it in water, in a bucket for example, or throw it in a ditch, though the latter is not good for the environment. Electric cars that have caught fire are sometimes hoisted into a shipping container full of water.”

How can we solve the problem of exploding batteries?

“It’s really hard to solve. Nobody keeps a record of the history of their devices and how often they have been banged. The only things that are monitored are electric vehicles.”

Are there any alternatives to lithium-ion?

“I am working on large-scale batteries, such as for wind farms, to store energy. Lithium-ion is less suitable for this as if a batter of this size catches fire, you definitely do not want to be around. Large-scale lithium-ion storage is not suitable for built-up areas. It is used in the Maximacentrale in the town of Lelystad, but that is on an island. I would not want a system like that in the surroundings of Delft.

We are working on new systems that use redox flow batteries. They do not store energy in fixed electrodes, but in liquid. They are expected to become cheap safe systems made from materials that can be mined in Europe. This is a disadvantage of lithium-ion as the raw materials come from countries with which we do not have the friendliest of relationships.”

We are working on a zinc-air battery called Rezilient – resilient with a ‘z’ from zinc. It’s a European project and we are still in the development phase, but the initial results are positive. But it will not be a solution for your phone’s battery.”