A new electrolyte mixture may prevent EV batteries from catching fire

Lithium-ion battery fires may not be all that common, but they are a concern — just ask electric vehicle makers and Samsung. Thankfully, research at Stanford might reduce the chances of those devices lighting up. Scientists have developed an electrolyte (the substance that carries lithium ions between electrodes) that won’t catch fire even at temperatures of 140F or more. The trick, it turns out, was extra lithium salt.

The team added as much of a particular lithium salt (LiFSI) as possible to a polymer-based electrolyte, bumping the mix from less than half of the electrolyte’s weight to 63 percent. The LiFSI served as an “anchor” for flammable solvent molecules, preventing them from catching fire. The combination lets a lithium-ion battery continue functioning at temperatures as high as 212F.

Unlike other attempts at non-flammable electrolytes, the polymer-based design is gooey and can fit into existing lithium-ion battery components. That lowers the costs and lets companies use their current manufacturing processes. You could see the technology reach real-world products quicker than rivals that would require custom (and potentially expensive) production methods.

There’s no mention of near-term attempts to commercialize the new battery tech, which was funded by the Energy Department. However, the researchers already see multiple benefits for electric cars. The design could not only lower the risk of EVs catching fire, but increase their range. Automakers frequently need to space lithium-ion battery cells to prevent them from heating each other. This advancement would let companies safely pack more batteries into a given area, allowing either higher capacities or more spacious interiors.

This could also prove useful for phones, laptops and other mobile devices where space and safety are priorities. You might eke out more runtime on a charge, or worry less about a fire in your pocket. This discovery wouldn’t prevent fires resulting from damage, but it could prove reassuring in everyday use.