updated 04:40 pm EST, Fri November 6, 2009
Metal-air ionic liquid could extend batteries
A new development by partly government-backed Fluidic Energy could potentially extend the battery life of notebooks, cars and other devices well beyond existing lithium-ion cells. Known as Metal-Air Ionic Liquid (MAIL), it would improve energy storage beyond relatively efficient zinc-air batteries by using an ionic liquid salt to conduct electricity that is much more stable and isn't prone to drying out either by accident or by eventual decay. The move would let battery makers use metals denser than zinc and therefore hold a much larger charge in a given volume.
The researchers estimate they can boost battery efficiency to between 900 and 1,600 watt-hours (Whr) in a pack with a mass of one kilogram (2.2 pounds), or about 11 times the energy of lithium-ion. Notebook batteries are significantly smaller, but would in many cases still last for significantly longer. If the improvements scale linearly, the 1.25-pound battery in a 17-inch MacBook Pro would still hold about 511Whr, or more than five times as much as the 95Whr battery of today.
Cars are a particular focus and the reason for the government funding, as they could extend the driving range of an all-electric car to between 400 and 500 miles and thus compete with some gasoline vehicles. A modern electric car like the Tesla Roadster officially lasts for just 244 miles using lithium-ion cells.
Challenges still remain, such as picking an ionic liquid that generates the intended properties but is still inexpensive enough to make sense versus existing technology. MAIL packs nonetheless have the potential to cost less than lithium-ion and would in many ways look and feel like their predecessors.
It's not clear how soon MAIL would reach the market, but the project unlike competing university projects is intended to reach shipping products first. [via jkOnTheRun]