One of the most exciting battery chemistries for electric vehicles is lithium-sulfur--it has the potential to store three times more energy than the lithium-ion batteries currently used in electric cars. Historically, however, it's had a number of problems. Early prototypes could only be recharged a few times, the lithium metal used in one of the electrodes caused short circuits and can react violently with water, creating a safety concern, and the carbon that makes the sulfur electrode conductive takes up too much space, decreasing storage capacity.

Earlier this year we reported on several advances geared toward addressing these problems, and noted that these advances had caught the eye of the chemical giant BASF, which is now working to bring lithium-sulfur batteries to market. But challenges remain, including bringing down costs. Now the Department of Energy has also taken an interest in the technology. This week Sion Power Cooperation (which is working with BASF) announced that it has received a three-year, $800,000 DOE grant to further develop the lithium-sulfur batteries for electric vehicles.

Maya Electric, a subsidiary of the battery maker Electrovaya, will be launching its Maya 300 electric vehicle on Tuesday. The car is an urban vehicle with a limited range (about 60 miles) and speed (25 or 35 miles per hour, depending on regulations regarding low speed vehicles). The company says that what distinguishes the car from other low-speed electric vehicles for sale is its use of Electrovaya's polymer-electrolyte batteries, which the company says store 60 percent more energy than other lithium ion batteries.

I spoke with Sankar Das Gupta earlier this year about the car and the batteries that power it.

The Fisker Automotive Karma, which looks like it will be the first plug-in hybrid sold in the United States, could be powered by lithium ion batteries from Enerdel, based in Indianapolis.

The two companies have signed a letter of intent for a supply contract, pending the results of reliability and performance testing, according to a press release from Enerdel. The battery maker also announced the opening of "the first commercial-scale production line for automotive-grade lithium-ion batteries in the U.S." The plant is in Indiana.

Enerdel uses lithium manganese oxide electrodes, the same type used in the batteries selected for GM's Volt plug-in hybrid. It was developed at Argonne National Laboratory with support from the U.S. Advanced Battery Consortium (comprising Ford, GM, and Chrysler).

Fisker had originally said that it would use batteries from Advanced Lithium Power, based in Vancouver, BC.

Plug-in hybrids use large battery packs that can be recharged by plugging them in, reducing gasoline consumption far more than ordinary hybrids, which can't be plugged in.