Toyota had hoped the next generation Prius would be equipped with advanced lithium ion batteries, the same general type as General Motors hopes to use in the production version of the Volt show car, thought to be on a timetable for 2010 introduction. But, GM’s car boss, Bob Lutz, has said that production of the Volt depends on making technological advances in batteries, and that current technology won’t support production of the Volt.
Toyota seems to agree.
Winding Road is reporting that Toyota has postponed use of lithium ion batteries in the next Prius, thought to be scheduled for a 2008 model year introduction, because the batteries pose an unacceptable safety risk. The Hybrid X show car Toyota displayed at the Geneva show this past March is believed to be a strong hint of the next generation Prius styling.
But that car was predicated on the expectation that it could use lithium ion batteries. Lithium ion batteries are the same general type as those which caused fires in Dell laptop computers, leading to a massive recall of batteries manufactured by Sony for several computer manufacturers.
Toyota has experience with automotive use of lithium ion batteries. It uses them in the Vitz, a very small van sold only in Japan. But the Vitz battery uses a different chemical technology than that contemplated for the Prius batteries and lacks the power necessary to be used in a true hybrid vehicle. Auto manufacturers have worked hard to develop a lithium ion battery for automotive use because it packs a lot more power for its size and weight than the nickel metal-hydride batteries currently used in hybrid vehicles. In 2005, Toyota took a majority stake in a joint venture with Panasonic devoted to developing an advanced lithium ion battery for hybrid cars.
Currently (pardon the pun), there are several private companies which sell Prius conversions to lithium ion batteries. Toyota, however, is unwilling to take the liability and publicity risks of using the lithium ion technology until it is far more confident about its safety.
What effect will this have on the next Prius?
Toyota isn’t addressing that question. Toyota had been targeting almost 100 miles per gallon and zero to sixty acceleration times of less than ten seconds.
Neither target would seem to be attainable without lithium ion batteries.