In November, SolidEnergy Systems will launch their first commercially available rechargeable lithium metal battery. While the initial battery will be used in drones, the company says the technology could be used in a variety of different consumer devices, from small devices like cameras and smartphones to electric cars.
Lithium metal batteries have long been toyed with because of their larger capacity over lithium ion, but they have a history of overheating and experiencing drastically reduced cycle life when recharged.
While working with professor Donald Sadoway, however, MIT student Qichao Hu found a way to replace the batteries anode with a thin metal foil. That thin material allowed the battery to shrink to about half the size — and while there were several more obstacles to work through, the project helped launch SolidEnergy Systems.
Along with being thinner than the traditional material, the metal foil can also hold more ions, leading to a larger capacity despite the smaller profile. The company demonstrated the first prototype in October 2015, which resulted in $12 million from investors. That prototype is half the size of the battery in the iPhone 6, but packs in more amp hours.
“With two times the energy density, we can make a battery half the size, but that still lasts the same amount of time, as a lithium ion battery,” Hu, now the SolidEnergy Systems CEO, said. “Or we can make a battery the same size as a lithium ion battery, but now it will last twice as long.”
While the initial change to the metal foil worked, that battery only worked at 176 degrees Fahrenheit or higher. The solution? A liquid electrolyte solution added to the foil allowed the battery to work without heat.
The years of development lead to a rechargeable lithium metal battery that’s non-flammable and can operate at a wide range of temperatures. According to SolidEnergy Systems, they can also be manufactured using the same equipment for traditional lithium ion batteries.