Will there be a winner?

I've noticed of late a number of articles reporting on events and technology enhancements relating to batteries--all types of batteries from those used in laptops to those powering hybrid vehicles. As examples, consider these news items: There are new restrictions on lithium-ion batteries which may affect your next airline flight. Lead-acid batteries for hybrid vehicles could be available in the next few years sporting much higher performance than current ones. And new nanotechnology developed for lithium-ion batteries for electric vehicles might more than triple their storage capacity as well as increase safety.

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If you traveled by air this year, you probably know firsthand about the U.S. Department of Transportation ruling that took effect on Jan. 1, 2008. It concerns lithium-ion batteries which are considered hazardous materials, especially onboard commercial airlines. You no longer can pack spare lithiumion batteries in your checked luggage. If you frequently scattered extra batteries in with your clothes and toiletries on previous flights, that practice now is prohibited.

However, it is all right to put them in your carry-on luggage if the batteries are in their original packaging or placed in individual plastic bags. Putting the batteries into individual plastic bags will prevent them from accidentally short-circuiting. However, you are limited to bringing on only two spares. Of course, the ruling does not apply to batteries installed in personal electronic devices. You still can carry on your cell phone, camera, and laptop.

According to a recent article in the MIT Technology Review, Australian researchers have developed a lead-acid battery for hybrid cars that packs more power than current batteries and does it at a fraction of the cost. Billed as the UltraBattery, it combines standard lead-acid technology with high-energy supercapacitors. The supercapacitors can generate megabursts of power over megacycles of use and not deteriorate significantly. The battery is said to last four times longer than conventional ones and can be manufactured at 25% the cost.

To support these claims, in mid-January, a Honda hybrid car was outfitted with an UltraBattery system and driven more than 100,000 miles on a test track. At the end of the test run, the batteries were inspected and found to be in perfect condition.

Moving over to electric-only vehicles, scientists at Stanford University are working on a new electrode technology for lithium-ion batteries that, according to the lead researcher on the project, is revolutionary. Initially targeted for smaller electronic devices such as laptops and cell phones, the technology replaces the traditional carbon-based anode with multiple silicon nanowires that have been embedded with lithium. The nanobattery is expected to produce 10 times more power than existing lithium-ion batteries.

Although a conventional silicon anode exhibits a higher storage capacity than carbon, it also has a much shorter life. In operation, the silicon anode swells as lithium atoms are absorbed during charging and shrinks when the battery is discharged. This expansion and contraction degrade the silicon and likewise the battery's performance. On the other hand, the nanowires are not adversely affected by the movements and last much longer. It is expected that the nanowire technology could be adopted for use in electric cars.

Whether supercapacitor lead-acid batteries or silicon nanowire lithium-ion batteries meet consumer expectations of plentiful energy at a reasonable cost, only time will tell. Hopefully, the wait won't be too long.

Paul Milo

Editorial Director

pmilo@evaluationengineering.com