A US startup is about to release a new kind of battery that offers twice the energy capacity of the lithium ion batteries we use in our devices today.

The doubling of capacity in these new lithium metal batteries comes from components that make the energy storage twice as dense as lithium ion, but the developers say their technology is just as safe and equally durable.

"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," Qichao Hu Hu, CEO of SolidEnergy, told Rob Matheson at MIT News. "Or we can make a battery the same size as a lithium ion battery, but now it will last twice as long."

Hu, a former researcher at MIT, founded SolidEnergy in 2012 with the goal of making 'anode-free' batteries.

The units they're just starting to commercialise swap out graphite as the anode – the electrode used in most rechargeable lithium ion devices for charging and discharging – and replace it with a much thinner lithium-metal foil, which can hold more ions, giving extra storage capacity.

When used in a smartphone, for example, the company's battery would be half the size of the lithium ion battery used in the iPhone 6, while offering a stronger electric current too – 2.0 amp hours, compared to the iPhone 6 battery's 1.8 amp hours.

Lithium metal has long been a focus for battery scientists because of the extra energy capacity it affords, but significant roadblocks have meant it's never been a serious option before now.

Previously, lithium metal was prone to forming compounds that increase resistance in the battery, reducing the life cycle of the component.

In the worst-case scenario, these kinds of compounds – including bumps in the anode called dendrites – can lead to charging issues, short circuits, and even flammable electrolytes, which can make batteries burn or explode.

Hu's team got around these issues by developing a lithium metal foil that doesn't need to be heated to function, and isn't flammable.

The foil, which is several times thinner than a conventional graphite anode – or one composed of carbon or silicon, for that matter – is also chemically modified to prevent the kind of negative reactions that previous lithium metal batteries were susceptible to.

But the most exciting thing about the lithium metal batteries is just how imminent they are. SolidEnergy says the first batteries will hit the market this November to power drones.

"Several customers are using drones and balloons to provide free internet to the developing world, and to survey for disaster relief," Hu told MIT News. "It's a very exciting and noble application."

Beyond that, the company says batteries for smartphones and wearable personal devices should become available from early 2017 – although it's unclear at this point which device manufacturers SolidEnergy might be working with, so we can't be sure what brands and products the batteries will ultimately turn up in (or when that might be).

But away from the world of smartphones and mobile devices, the biggest impact could be felt in devices that are a lot larger than personal electronics.

Hu says this kind of battery technology could make a "a huge societal impact" in electric vehicles, which isn't surprising, considering how much more energy it takes to move a car down the road than it does to power your smartphone (unless you're playing the power-guzzling Pokémon Go, of course).

"Industry standard is that electric vehicles need to go at least 200 miles (322 kilometres) on a single charge," Hu explains. "We can make the battery half the size and half the weight, and it will travel the same distance, or we can make it the same size and same weight, and now it will go 400 miles (644 kilometres) on a single charge."

Of course, we'll just have to wait and see which devices and vehicles end up incorporating SolidEnergy's batteries, but it's pretty incredible to think that even just your smartphone's staying power could double next year. In other words, we can't wait.