While I was looking for other information a couple of days ago, I ran across something on the web that surprised me. I didn't follow up at the time and now I've lost track of where it was, but maybe someone else here knows something about it.
The post or article I saw claimed that Tesla's supposedly-upcoming much- discussed "million mile battery" is lithium iron phosphate chemistry. LiFePO4 was something of an EV holy grail 15-20 years ago. Valence was offering their Saphion phosphate-based lithium modules around 2002. A123 was also an early LiFePO4 booster. Both claimed long cycle life and improved safety, and A123s were also known for ferocious specific power. When the cheap and cheerful Chinese low-power versions from Thundersky, CALB, and others started to appear in the States, a lot of them went into EV conversions. You can find discussions about this in the EVDL archive around 2006-2009. If memory serves, the main downside to LiFePO4 was specific energy. It just wasn't as good as what cobalt and manganese based chemistries offered. I also seem to recall some kind of patent-related LiFePO4 problem. This may have been the reason that hobbyists jumped on the cheap and cheerful Chinese LiFePO4 cells from Thundersky, CALB, and the like. Again dredging up from memory, I think that hose companies somehow (allegedly) made an end run around the patent and licensing concerns. Now, if I'm not mistaken, Tesla's development partner in the "million mile battery" is a Chinese firm. That's ... uh ... interesting. So has the EV world rehabilitated lithium iron phosphate's reputation? Has its specific energy problem been solved? What about licensing and patents? David Roden, EVDL moderator & general lackey To reach me, don't reply to this message; I won't get it. Use my offlist address here : http://evdl.org/help/index.html#supt = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = A developed country is not a place where the poor have cars. It's where the rich use public transportation. -- Gustavo Petro = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
