Rechargeable lithium-ion batteries are the mobile power sources of choice today, used in everything from laptop computers, smart phones and even electric cars. For years, though, they’ve been known to overheat and, at times, catch fire.
This was made painfully clear in January, when the lithium-ion batteries in Boeing’s newest commercial aircraft, the Dreamliner, caught fire, leading to a brief grounding of the planes until the fire hazard was resolved.
This is much less likely to happen with batteries made with magnesium. And magnesium ions in the batteries’ electrolytes, which transmit electricity, carry a double positive charge, increasing the device’s energy density, or the amount of electricity the battery can store.
Still, no one’s been able to make a commercially viable magnesium-ion battery, mostly because of fears of magnesium’s high reactivity with other materials in a battery, which would interfere with the movement of the ions through the electrolyte.
Liwen Wan and David Prendergast of the Lawrence Berkeley National Laboratory in California, conducted computer simulations that show this reactivity actually isn’t a problem. In the October issue of the Journal of the American Chemical Society, they write that the interference is much lower than had been feared, and therefore that a magnesium-ion battery would be more efficient than expected.