A Battery That Charges in Seconds
Imagine being able to charge your cell phone in a matter of seconds or your laptop in a few minutes. That might soon be possible, thanks to a new kind of nanostructured battery electrode developed by scientists at the University of Illinois, Urbana-Champaign. The researchers found that their electrode can charge and discharge up to 100 times faster than existing devices while holding the same amount of energy.
High-storage batteries that could charge and discharge quickly might make a number of still-marginal technologies much more attractive. For example, if you could recharge an electric car in minutes rather than hours, filling up your battery at a charging station would take no longer than the amount of time it takes to buy a tank of gas. And batteries that gave up their stored energy quickly could mean uninterrupted solar power, pitching in when the sun goes behind a cloud and solar cells stop producing.
Electrical storage devices known as capacitors charge and discharge very quickly, but because they hold their charge on the surface of metal plates, their storage capacity is limited. Batteries, on the other hand, can store much more energy because they hold their charge inside the bulk of a material, usually an oxide or a phosphate compound located inside the cathode. Unfortunately, because these materials are not good conductors of electric charge, it takes a long time to get the charge in or out of a battery.
Scientists have tried to get around this problem in the past by adding electrical conductors to the energy-storage material, but this reduces the material's volume, so it tends to lower the batteryâ€™s capacity. University of Illinois materials scientist Paul Braun and his colleagues came up with a novel solution, published online this month in Nature Nanotechnology. They built a tiny metal lattice with so many nooks and crannies that when it's filled with a charge-storage material, the electrons in the material never have far to go before reaching the metal and being conducted away.