To avoid thermal runaway, some battery cells are now being submerged in fluid

Batteries are the clean tech of all trades: They can help the electrical grid function, provide emergency power, and store renewable energy. But they have a flammability problem—and, depending on the scale, battery fires can be fatal.

Now, some manufacturers are creating batteries that can’t catch on fire because they’re surrounded by fluid.

One such battery comes from EticaAG, which manufactures lithium iron phosphate and nickel manganese cobalt batteries submerged in dielectric fluid, an electric-resistant liquid. The fluid prevents cells from catching on fire, so the “thermal spike” in the battery is contained, EticaAG President Matthew Ward told Tech Brew.

“If a cell has a thermal event, [it] doesn’t go to flame, and that thermal spike is just kept right there at the cell,” Ward said. “That one cell now has gone bad. But instead of cascading and the heat causing another cell to go off—and another and another—that doesn’t happen.”

EticaAG’s proprietary “special mix” of dielectric fluid is the result of “years and years of research,” Ward said. According to the company, it’s non-conductive, non-toxic, non-corrosive, and non-volatile.

XL Batteries also manufactures batteries that contain fluid, specifically pH neutral salt water. The company produces flow batteries, a type of rechargeable battery in which the molecules that store energy are dissolved in vanadium. XL Batteries replaces the vanadium and sulfuric acid in traditional flow batteries with pH neutral salt water, which prevents battery cells from igniting.

“It’s a literal water-based electrical solution,” XL Batteries CEO and co-founder Tom Sisto told Tech Brew. “[The batteries] could not catch on fire even if you tried.”

Sisto said non-flammability has become a “key differentiator” in batteries, especially in cases where AI chips are involved, like data centers.

“People just can’t tolerate the risk,” Sisto said. “These are $10 billion buildings full of irreplaceable Nvidia chips. Even if insurance wrote you a $10 billion check to replace the building if it caught on fire and burned down, you couldn’t get the chips even if you wanted to.”

And Prometheus Hyperscale, a data center developer, seems to agree: It just signed a multi-year agreement with XL Batteries to deploy the pH neutral salt water flow batteries at its data centers.

“We need batteries that offer performance at or above lithium,” Prometheus Hyperscale CEO Trenton Thornock said in a statement, “without the risk of overheating to deploy at our data halls.”