New lithium metal batteries offer double the energy capacity of today’s smartphones, drones, and electric cars, and could keep those devices running twice as long, creators said.

Creator, and MIT spinout, SolidEnergy Systems plans to bring the batteries to smartphones and wearables by early 2017, and to electric cars by 2018. This November, they will be available for drones.

“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. Or we can make a battery the same size as a lithium ion battery, but now it will last twice as long,” Qichao Hu, who co-invented the battery at MIT, told MIT News. Hu is currently the CEO of SolidEnergy.

The battery switches the common battery anode material–graphite–for very thin, high-energy lithium-metal foil. The lithium can hold more ions, and provides more energy capacity. Typically, lithium metal batteries are short-lived and volatile, but researchers modified them to be rechargeable and safer to use.

SEE: The future of electric cars: Why the battery race will define it and Musk is a genius

The iPhone 6 currently uses a lithium ion battery that offers 1.8 amp hours. The SolidEnergy battery is half the size, and offers 2.0 amp hours.

Researchers have tried to make rechargeable lithium metal batteries for decades, with no success, Hu said. “It is kind of the holy grail for batteries,” he added. Lithium metal reacts poorly with a battery’s electrolyte–a liquid that conducts ions between the cathode (positive electrode) and the anode (negative electrode). And measures to make the batteries safer usually cost its energy performance.

The SolidEnergy team used an extremely thin lithium metal foil for the anode, that is about one-fifth the thickness of a traditional lithium metal anode and several times thinner and lighter than traditional graphite, carbon, or silicon anodes–shrinking the battery size by half. The researchers also developed a solid and liquid hybrid electrolyte solution that doesn’t need to be heated to function.

The final result was a battery with the long lasting energy of lithium metal batteries, but the safety and longevity of lithium ion batteries, Hu said.

In 2012, the SolidEnergy team won the first-place prize at the MIT $100K Entrepreneurship Competition’s Accelerator Contest, and was a finalist in the MIT Clean Energy Prize. The team also placed second at the national Clean Energy Prize competition at the White House.

SolidEnergy debuted the first-ever working prototype of a rechargeable lithium metal smartphone battery with double energy capacity in October 2015, and earned more than $12 million from investors.

If the technology works, the implications are major: Right now, electric cars can go about 200 miles on a single charge. Hu said he can make their battery half the size and half the weight, and it will travel the same distance–or, he can make it the same size and weight, and it will go 400 miles on a single charge.

Elon Musk said in June that Tesla is currently capable of making an electric car that can travel 400 miles per charge, but that doing so wouldn’t make economic sense right now. Instead, the company plans to create a car with a 500-mile range by 2025.

And, as drones continue to infiltrate everyday life and maybe even your office someday, a longer battery life could make them even more commonplace.

The 3 big takeaways for TechRepublic readers

  1. MIT spinoff SolidEnergy Systems created a high-capacity lithium metal battery that offers double the power of today’s smartphones, drones, and electric cars.
  2. The company plans to release the battery for drones this November, for smartphones and wearables by early 2017, and for electric cars by 2018.
  3. If the battery works, it could have important implications for how we use electric cars, drones, and other devices.