Lithium is a volatile material, and when it is densely packed into cells as it is in lithium ion batteries, an internal short can cause a chain reaction and result in a fire. Although Sony Electronics touted the energy density and subsequent energy capacity of lithium ion batteries in the past, company President Stan Glasgow said lithium polymer batteries would "likely" replace their more dangerous ion counterparts. Sony is now working with Dell, Toshiba, Apple Computer, Lenovo and others to take back millions of lithium ion batteries that they have supplied with their notebooks during the last two years.
There is not too much more power we want to cram into lithium ion," Glasgow said.
Lithium polymer batteries are safer because the lithium is contained in a polymer gel instead of cells, which means they are less energy dense, but not prone to catching fire during a short. Also, lithium polymer has always had its supporters because the gel can easily be fitted into tight empty spaces in a notebook case. Unfortunately, the battery is not known for its long lifespan. When Mitsubishi used lithium polymer batteries in its Pedion notebook in 1997, it was a commercial failure, although the $6,000 price tag and mechanical issues likely contributed to the computer's downfall.
Some companies have decided to make their laptops safer by eliminating lithium altogether. MTI Micro Fuel Cells and other companies are hoping that their fuel cells -- which pass methanol through a membrane in order to obtain electricity -- are the next laptop battery, while Zinc Matrix Power and PowerGenix are moving to zinc-based batteries for notebooks and other devices. Glasgow said that these technologies are still a bit down the road.
"I don't think anything new is going to be available in the next 12 to 18 months," he said.
Zinc Matrix Power has said it hopes to start shipping zinc-based batteries next year.