by Julian Spector
September 16, 2020

It’s been over a year since the McMicken battery facility in Surprise, Arizona began to smoke and eventually exploded.

We’ve learned a lot since then. I spent the last several weeks digging through a series of investigations, tracing what happened, why safety systems failed, how designs should change and what approaches can better protect firefighters. (You can read those analyses here, here and here.)

But now it’s time to take a step back from the details and the theories and think broadly about what all this means for the energy storage industry.

A lot has already changed. But there’s more work to do to prevent another calamitous failure.

Battery cell failure should prompt a service event, not a catastrophe, said storage entrepreneur Christina Lampe-Önnerud. She previously founded battery manufacturer Boston-Power, but since 2012 has been working on redesigning battery cells as CEO of startup Cadenza Innovation.

Batteries need to compete on cost. Designing systems to minimize the damage from thermal runaway leads to higher embodied costs, Lampe-Önnerud explained. It also reduces energy density because installations need physical distancing to prevent potential fires from jumping between racks or containers.

“It is not enough to say, ‘We’re going to put insulation between the units,’ because you don’t stop the root cause,” she said. “In order to get to cost efficiency, you have to get to the root cause, which is thermal runaway.”

That’s easier said than done, of course. For one thing, the battery needs to identify and isolate a failing cell faster than is possible with electronic controls, Lampe-Önnerud said. Cadenza’s technology uses chemical and mechanical triggers inside the cell to shut things down immediately if something goes wrong.

After eight years working on it, Cadenza is taking its technology live with a demonstration at the New York Power Authority headquarters by the end of this year (the coronavirus pandemic pushed back the timeline of its plans). It’s too early to say when it will get to widespread commercial use, but it serves as a reminder that lithium-ion innovation is not over, and expectations around an acceptable level of thermal runaway risk could shift if better, cheaper options become available.