A new type of battery that lasts for days with only a few seconds' charge has been created by researchers at the University of Central Florida.
The high-powered battery is packed with supercapacitors that can store a large amount of energy. It looks like a thin piece of flexible metal that is about the size of a finger nail and could be used in phones, electric vehicles and wearables, according to the researchers.
As well as storing a lot of energy rapidly, the small battery can be recharged more than 30,000 times. Normal lithium-ion batteries begin to tire within a few hundred charges. They typically last between 300 to 500 full charge and drain cycles before dropping to 70 per cent of their original capacity.
It is uncommon for a lithium-ion battery to withstand more than 1,500 charges before it fails, the Florida researchers claimed. Other estimates put the lifecycle of batteries currently on the market at a maximum of 7,000 charges.
To date supercapacitors weren't used to make batteries as they'd have to be much larger than those currently available. But the Florida researchers have overcome this hurdle by making their supercapacitors with tiny wires that are a nanometre thick. Coated with a high energy shell, the core of the wires is highly conductive to allow for superfast charging.
"For small electronic devices, our materials are surpassing the conventional ones worldwide in terms of energy density, power density and cyclic stability," said Prof Choudhary. Cyclic stability refers to the number of times a battery can be fully charged and drained before it starts to degrade.
The battery isn't yet ready to be used in consumer devices, the researchers said, but it shows a significant step forward in a tired technology.
Separate research into the technology has recently led to the creation of tiny "lithium metal" batteries that hold twice as many ions, and another nanowire battery that can withstand 200,000 charges.
Lithium-ion batteries are commonly used in smartphones, tablets and wearables, but are known for losing capacity over time and can be dangerous. It was a fault in this kind of battery that recently caused Samsung's Galaxy Note 7 device to overheat and, in some cases, explode.