Well, to be exact .... all Lithium Ion batteries die for one reason. Loss of electrolyte.
Plating is just a way to loose electrolyte. Without moving Li Ions the battery can't work. The Ions that move are in the electrolyte. ________________________________ From: Michael Ross via EV <ev@lists.evdl.org> To: Bill Dube <billd...@killacycle.com>; Electric Vehicle Discussion List <ev@lists.evdl.org> Sent: Wednesday, February 25, 2015 4:14 PM Subject: Re: [EVDL] Cold Charging Lithium Experiences Bill, I think the issue is too fast a charge, for the temperature, and cell composition. Which is to say, for a given cell, we have little information worth paying attention to, that would be informative. I think the whole industry suffers from a lack of understanding due to inadequate testing methods. Then you throw in unwary marketing people, who may paste the same graph, table or specification into a webpage or brochure, imagining that it is simple - the same electrode composition must produce the same performance and limitations. When we say LiFePO4 we are only talking about the anode. We have a graphite cathode, but how it is formed makes a difference. The electrolyte package which we are never privy to is unknown and may as important as all the stuff we know about.. I do recall a brief discussion of this last year on this list where it came up. I quoted a professor here in the NCSU Freedm Center (where they have luminaries like the guy the inverted the IGBT, and have worked there on prototype lithium cells), he told me he didn't know anything about lithium plating. Was he talking about a specific chemistry? I didn't know enough then to question him. I have found literature detailing the process of plating so he either didn't know, wasn't talking, or meant something I wasn't expecting. I have a few papers on this which I will send you. They seem to support the idea that plating happens. Mike On Tue, Feb 24, 2015 at 12:50 AM, Bill Dube via EV <ev@lists.evdl.org> wrote: > Does the data presented apply to Li-Fe-PO4 or only to Li-Ion metal oxide? > I know that they have a distinctly different chemistry than metal oxide > cells, and I know that they have different charging characteristics. It is > likely they have different cold weather charging behavior as well. > > I looked up a few references on the web and you seem to be able to charge > LiFePO4 cells down to -10 C quite normally with no caution mentioned about > going to lower temperatures. An example is Powerstream Batteries < > http://www.powerstream.com/LLLF.htm> show in their specifications charge > down to -40 C. The A123 cells spec sheet show a temperature range of 55 to > -30 C. I don't see any reference to lithium plating out or anything drastic > when I restrict my search to LiFePO4. ( I also ignored blogs and forums. I > just looked up papers and manufacturer specs.) I think that cold weather > effect may be restricted to lithium-ion "metal oxide" cells. > > That reflects my personal experience with a pack of LiFePO4 ThunderSky > cells in freezing Colorado weather with outdoor storage. The vehicle took a > few miles to warm up the pack, and range suffered a bit because of voltage > sag due to cold weather, but that was about the extent of it. > > I think it is important to not group all Li-ion in the same basket. The > LiFePO4 cells share a few of the characteristics with metal-oxide cells, > but are quite distinct in many ways. Also, there are a great variety of > metal oxide li-ion cells, which are distinct from each other. > > Bill Dube' > > snip > -- To invent, you need a good imagination and a pile of junk. Thomas A. Edison <http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html> A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone (919) 631-1451 Cell michael.e.r...@gmail.com <michael.e.r...@gmail.com> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150225/12b3e298/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150225/f84b63d4/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
