March 11, 2009
MIT Researchers Develop Revolutionary New Lithium Batteries
U.S. scientists are unveiling an invention they believe could lead to a smaller, lighter and more power-packed lithium battery than anything available on the market today, the AFP reported.
Experts say the current batteries made of lithium iron phosphate (LiFePO4) are good at storing large amounts of electricity, but aren't so good at releasing it"”meaning they can better dispense the power in a steady flow than discharging it or gaining it in a sudden burst.This means electric cars can perform better when traveling along highways at a constant speed rather than when they are accelerating, and their batteries take hours to recharge after use.
Scientists originally thought this was due to charged lithium atoms, which, along with electrons, move too sluggishly through the battery material before arriving at the terminal to deliver their charge.
However, Massachusetts Institute of Technology (MIT) researchers say the problem isn't with the ions but how the ions gain access to nano-scale tunnels that riddle the material and transport the electrons to their destination.
The researchers were able to solve this problem with a lithium phosphate coating that prompts the ions towards the tunnels, making them zip instantly down the tunnel entrance and to the terminal.
The authors said in the British journal Nature that a small cellphone battery can be recharged in just 10 seconds due to the improved ion flow.
Therefore, the team suggests that a large battery used to power a plug-in hybrid electric car could be recharged in just five minutes, compared to current rate of up to six or eight hours.
It would only be possible, that is, with a beefed-up electricity supply, they added.
The newer LiFePO4 does not degrade as much when repeatedly charged and recharged, unlike other battery materials. MIT said in a press release the new developments could lead to smaller and lighter batteries, which will not need such heft to deliver the same power.
MIT also said two companies have already licensed the invention, which was supported by U.S. government funds.
An official statement said that because the material involved is not new"”the difference is the way it is made"”the work could make it into the marketplace within two to three years.
The U.S. and the rest of the world is on an ongoing quest to find an alternative to conventional electro-chemical batteries, which are heavy, lack energy density and take time to recharge.
So far, experts have unveiled ideas ranging from updated lithium-ion technology to hydrogen batteries and combinations of a battery with so-called ultracapacitors that harness exotic materials such as barium titanate to deliver a charge.
Image Caption: A sample of the new battery material that could allow quick charging of portable devices. Photo / Donna Coveney
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