Apr 13, 2010

New Small and Large Scale HOPE for Batteries MIT

The search for the more efficient and more electrical energy stored batteries are continues to be developed.
The lightweight rechargeable lithium-air or lithium-oxygen batteries are also being developed by the scientists with reason of its ability to store electrical energy three times higher than current conventional lithium-ion batteries.

Lithium-air battery concept actually has long been found by the researchers, but the development is hampered by the search for electrode materials that can cause an electrochemical reactions. The MIT ( Massachusetts Institute of Technology ) researchers have now come up with solutions for gold and platinum electrodes as a catalyst that have higher level of activity and efficiency than conventional carbon electrodes. This new discovery will also pave the way to find the type of electrode material that is cheaper and more efficient.

It makes lithium-air battery has three times higher energy density because of the lighter cathode. In addition, oxygen is easy and freely to get and doesn't need to be stored in the battery.

Molten Metal Battery MIT professor Donald Sadoway and graduate student David Bradwell observe one of their small test batteries in the lab. Patrick Gillooly/MIT
Molten metal may not be what you want in your smartphone battery, but it turns out to work great for larger grid-scale batteries. MIT engineers have created devices that can provide up to 20 times as much current as lithium-ion batteries with the same electrode area, according to New Scientist.
The new battery simply consists of tanks filled with three liquid layers kept at 1,292 degrees F (700 degrees C). Molten magnesium sits on top, and antimony sits on the bottom. The middle layer consists of a compound mixture of the two outer layers.

Charging the battery with electricity breaks down the middle layer, and thus enlarges the upper and lower layers, while discharging reverses the process, in a chemical reaction that releases electrons to provide power. Once running, the battery also creates enough self-sustaining heat to keep everything deliciously molten.
A battery as large as a shipping container could deliver a megawatt of electricity, or enough to power about 10,000 100-watt light bulbs for several hours. 

Its cheaper material costs compared to lithium make it a more cost-effective candidate for scaling up the power grid.

Some utility companies and cities have already turned to sodium sulfur batteries as backup power that can ease reliance on the aging transmission grid -- the Texas town of Presidio recently charged up the largest battery of this type in the U.S. But the molten metal battery technology could provide part of a newer energy infrastructure that supports a growing variety of renewable energy sources.