Hold onto your hats: Graphene, the one true savior, has now found a use in the one technological arena that needs it most: batteries. Namely, engineers at Northwestern University have found that a specially-crafted graphene electrode can allow a lithium-ion battery to store 10 times as much power and charge 10 times faster -- and last longer, too.
In state-of-the-art lithium-ion batteries there is a graphite anode, a metal oxide cathode, and an electrolyte containing a lithium salt. When discharging, lithium is forced out of the anode (+) and into the cathode (-), and during charging the reverse occurs. In essence, anode's capability to handle and store lithium dictates the output voltage, total capacity (mAh), and charging speed. The Northwestern researchers, using graphene, have completely upended the very restrictive limitations of commonly-used anodes.
The new anode is still made from sheets of graphene (graphite is simply millions of layers of graphene) but the researchers have punched millions of tiny (10-20nm) holes through each layer of graphene (pictured right). Instead of each lithium ion having to travel around the outer edge of each graphene layer, they can now just jump through the holes (or nanoholes, as they're being called). Furthermore, the engineers introduced clusters of silicon between each layer of graphene; graphene on its own can only carry one lithium ion per six carbon atoms, but each silicon atom can hold four lithium ions. The combined effect is an anode that can store 10 times more power (30,000 mAh instead of 3,000) and 10 times the charging speed (15 minutes instead of two hours). If you haven't already shuffled slightly further under your desk to hide your excitement, get this: the Northwestern battery, after 150 charge/discharge cycles, is also five times more effective than any lithium-ion battery currently on the market.
As always, we have to ask the question: When will this new tech find its way into a battery near you? Northwestern doesn't give a clear answer -- it only goes on to say that the team is now working on improving the cathode and electrolyte. If we go on previous battery-related discoveries, though, and assuming this discovery can be repeated at an industrial scale, we might see week-long smartphone batteries within a couple of years.
Suffice it to say, the flip side of this discovery is that batteries could be made 10 times smaller and yet have the same capabilities of today's offerings. If you've ever seen the battery in an iPad or smartphone, you'll understand that batteries are really the only significant hindrance in the miniaturization of gadgets. If the Northwestern battery comes to fruition, the bulky battery pouches on everything from remote controls to laptops to hearing aids would simply go away.
Read more at Northwestern University(Opens in a new window)
