According to this article Lithium Ion batteries will take over from the current Nickle Hydride for hybrid cars within the next five to eight years because it has better characteristics (saying GM. Toyota, and Ford agree on this point). Toyota already has a Lithium Ion battery in a car sold in Japan (not a hybrid, but used for start/stop ICE operations). A high executive in Toyota implies they may use it sooner. Article states that the Prius will be updated in 2008. Here is the article==> http://www.carlist.com/autonews/2005/autonews_188.html Other articles (not this one) indicate that more energy can be captured by Lithium Ion from regenerative braking and that it makes plug-in capability more possible.
Maybe Lexus hybrids will have Li-ion and Toyota hybrids (exception of the next Prius) will have NiMH until prices come down. "The Maganese Lithium-Ion battery has a durability problem." The info in that article is kinda outdated. According to autoweek article, these manganese lithium ion battery are to last 15 years / 150,000 miles. If you remember, Toyota recently bought 20% of Fuji Heavy Industries Ltd (Parent of Subaru) to gain access to their manganese lithium ion battery.
There was a good article in the Fall, 2005, issue of Green Car Journal, regarding the use of Lithium-Ion batteries in the plug-in modification of the Prius, which is supposed to be available as an aftermarket conversion beginning in 2006 (for a considerable price). The company offering the conversion is using a 9 kWh battery developed by Valence Technologies. The information from that company claims that they have solved the safety issues for the battery with the development of their Saphion technology, which is being used for smaller batteries such as for lap top computers. Sounds like a promising technology.
