The paper you sent you linked me is dated 2007. The work with HPC did not begin being published until 2010. The paper is about the cathode performance. The problems are at the anode, when fully charged,and at too high temperature. Maybe the paper gets to this I haven't had a chance to read it all yet.
I got my information about LFP from the scientist at Dalhousie University, Dr.Jeff Dahn, in a phone conversation IIRC. I can't remember if it is in one of those graphs in the video or not. The upper limit for a FULLY CHARGED LFP cell is 40°C (104°F) - above that it is trouble. He said another chemistry started having trouble at 35°C (95°F). I believe it was the original chemistry and electrolyte LiCoO2.but please don't hold me to that. I apologize, I was being too casual when I started accumulating information on this - and there is a great deal, of which I am still just scratching the surface. I wish there was more definitive published information on this, It is why I was trying to fund a lab with HPC equipment. This bad reaction is also mitigated by good electrolyte chemistry. You can run any Li ion cell with fast cycles at 140°F and it may not deteriorate because there are infinite number of ways to run test cycles that do not mess the cells up. The testing needs to be run in a way to detect the failures so you can compare chemistries based on when the failures start to happen. WIth the old testing it took a very long time to get good results. WIth HPC high precision coulometry you can start getting good information in a few weeks, because HPC can detect the damage at very low levels. Here is a comprehensive list coming out ot Dahns lab. Search it for Aaron Smith and Chris Burns to get the pertinent titles. http://www.dal.ca/diff/dahn/publications.html This is the 1st publication about HPC: 422. A.J. Smith, J.C. Burns, S. Trussler and J.R. Dahn, Precision Measurements of the Coulombic Efficiency of Lithium-ion Batteries and of Electrode Materials for Lithium-ion Batteries, J. Electrochem. Soc. 157, A196-A202 (2010). . Don't look below that one. The video again: https://www.youtube.com/watch?v=pxP0Cu00sZs HPC equipment: http://www.novonix.ca/ On Wed, Apr 1, 2015 at 1:21 PM, paul dove via EV <[email protected]> wrote: > Where do you get your information. > > LiFePO4 if good even at 140F. > > http://ecst.ecsdl.org/content/3/36/3.full.pdf > > > > ________________________________ > From: Michael Ross via EV <[email protected]> > To: Jeff Major <[email protected]>; Electric Vehicle Discussion List < > [email protected]> > Sent: Wednesday, April 1, 2015 11:42 AM > Subject: Re: [EVDL] ENERDEL Battery Experiences > > > Jeff, > > I am not sure why performance at ambient temperatures should make anyone > feel confident about a cell. LFP for instance, starts to have serious > difficulties at 104°F if it is fully charged. That is certainly ambient > here in North Carolina; and that is free air, not boxed up with significant > amperage scooting about. > > I must tell you, I don't have an axe to grind here. I simply want to point > out a better way to go. That is to get better information for all. And > better testing with in the industry. ENERDEL just popped up on my radar > is all. They have an website that is light on good information and I waded > in. I am happy to see that behind the curtain they may have more on the > ball. > > I have been scanning the course work you provided to me, and it is very > nice. When ENERDEL discusses cycle life (around page 279) I can see they > clearly understand the reactivity of the positive electrode at very high > SOC and how temperature makes that much worse for the electrolyte. They > clearly have good information to work with and probably are engaged with > Dalhousie University or the spin off Novonix to get good testing done. I > am duly impressed. > > I still have not figured out what chemistry they have chosen. From what I > have seen so far, they speak assiduously, only in general terms regarding > their own cells. If they are using some inferior chemistry and electrolyte > package it is clearly not because they don't know better, so I bet they are > OK. Provisional blessing on them until I am better educated. > > Thanks for taking the time to address this with me. > > Mike > > > On Wed, Apr 1, 2015 at 10:19 AM, Jeff Major via EV <[email protected]> > wrote: > > > I doubt that EnerDel and its customers have overlooked anything as basic > > as performance and life at ambient temperatures. It appears to me that > > Hoegberg is comparing to some float stand-by application and then > > misinterpreting the presented data. But whatever. They have millions of > > cells in the field and no complaints of which I am aware. > > > > -------------- next part -------------- > > An HTML attachment was scrubbed... > > URL: < > > > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150401/e6911ad9/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) > > > > > > > -- > 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. 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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) 585-6737 Land (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone (919) 631-1451 Cell [email protected] <[email protected]> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150401/c3634750/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)
