Bigger, better batteries

IBM is currently working on the development of a new type of battery. The technology is called lithium-air or lithium oxygen. Their goal is to create a powerful new battery for electric cars with a greater range per charge. The systems would also be comparable in size, weight and cost to a standard gasoline system.

Winfried Wilcke is the senior manager for IBM’s “Battery 500 Project” at the Almaden Research Center in San Jose, California, whose goal is to create a battery that is 10 times more efficient than more common lithium ion batteries. Currently, a typical battery powered car has a range of 160 km and their goal is to extend that to 800 km.

Litium ion batteries use air drawn from outside of the battery as a reactant. Lithium-air batteries electrochemically couple a lithium anode to atmospheric oxygen through a carbon based air cathode. By comparison, lithium ion batteries use much heavier compounds to induce the same reaction.

Not only will this weight savings improve the efficiency of the cars they are installed in, but it also increases the efficiency of the battery due to it’s higher energy density thanks to the lighter cathode. As another benefit, since oxygen is available in the atmosphere, it does not need to be stored in the battery.

MIT is also working on developing this technology.

Lithium-air batteries have yet to become commercially available because there is a lack of understanding about what kinds of materials could be used for an electrode to promote the reactions that take place in this kind of battery. Early studies have demonstrated that electrodes with gold or platinum as a catalyst produce a higher level of electrochemical activity than more common carbon electrodes.

The MIT team is aware that many issues need to be addressed before the public can use this genre of battery.

As reported by Gizmag.com, “Lithium in metallic form, which is used in lithium-air batteries, is highly reactive in the presence of even minuscule amounts of water. This is not an issue in current lithium-ion batteries because carbon-based materials are used for the negative electrode.”

“MIT associate professor of mechanical engineering and materials science, Shao-Horn, says the same battery principle can be applied without the need to use metallic lithium; graphite or some other more stable negative electrode materials could be used instead, she says, leading to a safer system.”

The biggest difficulty research teams have to face is the rechargeability of these batteries. In order for any battery to be useful for cars or portable electronics it must be able to sustain multiple charge and discharge cycles.

Also, recharge time is an issue yet to be solved. The goal would be able to have fast charging stations capable of charging a battery to 80 per cent within 30 minutes. Currently it is not certain if the batteries could handle such rapid charge cycles.

Lawrence Seeff, head of global alliances for Better Place argued the feasibility of such charging stations, reported the NYTimes.com.

“It’s physically possible to have a fast-charge mechanism and a fast-charge outlet, but can the grid support it?” Mr. Seeff said. “And what do we define by fast-charging? Is it 20 minutes, 10 minutes, 30 minutes? Because if you have two people waiting to fast-charge, you could be waiting an hour.”

Only time will tell as progress is made surrounding this project. There are multiple companies working on developing lithium-air batteries but no definite project completion date has been set.