Lithium-ion is the best battery technology now available for vehicles, but could tap out its promise by the end of the next decade.

That's the view of Ted Miller, senior manager of energy storage research for Ford Motor Co., who was speaking Wednesday at an energy storage conference at IBM's Almaden laboratory near San Jose, Calif.

"There are foreseen limits of lithium ion technology," Miller told the audience, showing a chart that put a rough 2017 endpoint on squeezing improvements out of that particular battery chemistry.

"That will limit everything from driving range to how much we can decrease the package size," he added - the latter an important consideration when designing batteries for passenger cars.

That's why Ford is researching next generation battery chemistries, such as lithium-air, Miller said.

That's also IBM's focus into battery research, which hasn't been a focus of the IT giant, but has grown out of work it has done on nanoscale membrane technology (see IBM Delves Into Lithium-Air Batteries, Water-Cooled Supercomputers).

Lithium-air and zinc-air batteries generate power by exposing metal and an electrolyte to oxygen, oxidizing the metal and releasing energy (see Electricity From Air and Zinc? A Growing Chorus Says Yes).  

Theoretically at least, lithium-air batteries could provide about 10 times the energy density - the amount of energy stored per kilogram – than the roughly 200 kilowatts per kilogram of today's lithium-ion batteries, IBM's Spike Narayan has said.

In the meantime, Ford is looking to lithium-ion as the best technology for the electric and plug-in vehicles it plans to start releasing next year. An electric Transit Connect van is scheduled for 2010, followed by the electric Focus in 2011 and the plug-in hybrid in 2012.  

While Ford hasn't disclosed the model for the plug-in hybrid, it is testing plug-in versions of its Escape hybrid right now, and earlier this month unveiled its technology for connecting plug-in vehicles to utilities to control when and how much they charge (see Ford Deploys Electric-Car-to-Grid Communication System).