Preventing Thermal Runaway in Lithium‑Ion Batteries: Proven Strategies

Lithium-ion batteries are everywhere, from electric vehicles to your phone, but the electronics component can fail in big ways. In fact, the battery continues to be a bit of a mystery.

"We are still in a learning process," said Roeland Bisschop, project manager at RISE Research Institutes of Sweden , in a live presentation Tech Briefs presentation this month. "There are still many things that we don't understand about lithium-ion batteries."

Collaborating with industry, academia, and the public sector, RISE Research tests the limits of technologies, including batteries.

When you exceed the safe operating conditions of a cell, you may end up with a thermal runaway, an event characterized by increasingly elevated temperatures.

If pressure builds up in the battery cell, the heat could lead to a rupture in the battery casing, which releases flammable, toxic gases that may or may not ignite.

To reduce these kinds of explosive risks, testing must be performed to ensure these batteries are safe in the event of thermal runaway, says Bisschop, and simulation can fill in the gaps where testing isn't possible.

In a live Tech Briefs presentation titled Reducing Battery Thermal Runaway Risks Through Testing and Simulation, a reader asked:

"How do you ensure that runaway is contained to as few cells as possible and does not go beyond the module?"

Read Bisschop's edited response below.

Roeland Bisschop, Project Manager, RISE: I think it will depend on the combination of both testing and performing simulations, to have an understanding of the characteristics of your specific battery cell that you're using and the challenges that you're facing and if it may fail. Regardless, you should be designing your systems, expecting that one of your cells may fail at some point in time.

When it comes to specifics: One can look at distancing between the cells, applying some heat sinks in your battery modules, or in between the cells, or having some emergency cooling systems. In our specific tests, we looked at injecting fire-suppressant agents directly into a battery pack, and that way we were able to reduce the risk for thermal runaway propagation, but that's kind of a last-resort method.

How have you dealt with thermal runaway risks? Share your questions and comments below.