A paper published today by Stanford University researchers outlines a way to make lithium batteries a lot safer, opening the door to a host of new applications in everything from smartphones to electric cars.
The paper, which ran in the journal Nature Nanotechnology, details the use of a carbon nanotube layer to isolate a lithium battery's anode, protecting it from the rigors of heavy use.
Lithium-ion batteries are one of the most efficient ways to pack a lot of power into a small space, and they're consequently in heavy use -- one of them is probably powering your smartphone as you read this. The Tesla Model S also uses a lithium ion cell for power. But lithium-ion batteries use several other materials as anodes, even though a lithium anode would be substantially more efficient.
The reason for this? A lithium anode tends to form irregular, "mossy" metal deposits with use, rapidly decreasing efficiency and causing potential safety issues. But the Stanford team, led by Professor Yi Cui, used a coating of amorphous hollow carbon nanospheres to isolate the anode and prevent the formation of the unwanted deposits.
The effect is more efficient batteries that last roughly 50% longer than units without the carbon nanosphere treatment, with consequently broad implications. Safe lithium batteries could mean longer ranges for electric cars, longer lives for portable electronic devices and much more.
Some of the same team members were responsible for a another potential Li-on battery advancement, outlined in another paper last year, this time of a flexible carbon nanotube "skin" for existing silicon anodes, which helps stop them from cracking and losing efficiency.