Toyota may be on top of the world right now having the brought the first practical modern hybrid cars to production and selling more hybrids than anyone else, but that doesn't mean they are in the lead on everything green car related. They just announced a test fleet of plug-in hybrids but thanks to their decision to stick with Panasonic as a battery supplier, they are clearly struggling with lithium ion battery technology.

At the Management Briefing Seminars this week, Toyota's Justin Ward said that lithium ion is not ready for the automotive market. More precisely, although you won't hear this publicly from Toyota, Panasonic's lithium chemistry is not ready. As Bob Lutz told the conference on Thursday not all lithium ion is created equal.

Panasonic made the odd decision to stick with the same cobalt-oxide cathode chemistry that's used in most consumer electronics batteries. That's the same chemistry that has an unfortunate tendency toward thermal runaway (fiery explosions) if not handled properly. A123 uses iron-phosphate that is much more stable and like Altairnano's titanate chemistry is able to handle faster charging and more temperature variation.

It looks like Toyota made the wrong choice of technology and is now paying the price by having to delay the next generation Prius and also playing down the overall prospects for plug-in hybrids and EVs to cover their tracks.

[Source: Automotive News]