I honestly am not qualified to parse the linguistics of this. I will note that the definitions I used, never talked about electrons in regard to the electrodes; it talks about cation and anions. Not the same thing. THe definitions of cathode and anode are related to cations and anions - electrochemical terms..
In the external circuit electrons are moving, between the electrodes it is ions. Chemically there is a charge imbalance that is created or relieved by electrons at the terminals of the conductors. When there is no imbalance the lithium ions reside in the positive electrodes, intercalated in the the lithium metal oxide (or phosphate with LFP), this is a stable state even when the terminals are connected. If you create an imbalance, in other words a potential difference, at the terminals the ions will be attracted to and intercalate in the graphite negative electrode. This is stable if you do not put a connection between the terminals. At Dalhousie they have been working with lithium cells for decades. Maybe he was talking about with the high precision coulometry they developed - that is fairly new work. Aaron Smith's first paper on the subject was in 2010. On Fri, Feb 27, 2015 at 6:05 PM, tomw via EV <[email protected]> wrote: > That is how I’ve seen them referred to in articles I read. > > In a zinc – copper voltaic cell electrons are produced by oxidation of zinc > at the /anode/ which is considered to be the /negative/ electrode since it > "pushes" electrons into the external circuit. The electrons flow through > the external circuit to the /positive/ copper /cathode/ where they reduce > Cu^+2 ions in solution to copper atoms. Ref: Chemical Principles, > Masterton > & Slowinski. In this case the anode is negative, cathode is positive. > > This is equivalent to the discharge of lithium-based cells since no > external > power is applied between the electrodes. In this case the lithium atoms in > the /graphite/ lose an electron and flow through the electrolyte to the > LiFePO4 electrode, and the electrons flow through the external circuit to > the LiFePO4 electrode. Using the above convention, the /graphite/ would be > considered the /negative/ electrode and /anode/. > > Here is where the confusion enters: > > During *charging* the intercalated lithium atoms in the/ LiFePO4/ cathode > lose an electron and flow through the electrolyte to the graphite and the > electrons flow to the graphite through the external circuit. So by the > above > convention ("pushing" electrons) the LiFePO4 electrode would in this case > be > the negative electrode, the opposite of when discharging. > > Also, in a DC glow discharge the /negative/ electrode is called the > /cathode/. It collects positive ion (cation) current from the plasma and > electron current from the external circuit. The /positive/ electrode is > called the /anode/ and collects electron current from the plasma and > “pushes” electrons into the external circuit. Ref: Gaseous Electronics, > Hirsch & Oskam. Note that external power must be supplied to sustain the > plasma, so this is equivalent to the *charging* half-cycle of a LiFePO4 > cell > where the LiFePO4 electrode acts as the anode pushing electrons into the > external circuit. > > So it depends on whether there is an external power source applied > (charging, in the case of batteries). I think generally the literature > uses > the "discharging" terminology. > > Batteries are definitely consumers of energy since they dissipate energy > during both charge and discharge, so you always get less energy out than > you > put in. > > I thought Dahn said they had just begun studying batteries, but guess I was > wrong. > > > > > -- > View this message in context: > http://electric-vehicle-discussion-list.413529.n4.nabble.com/Cold-Charging-Lithium-Experiences-tp4667675p4673996.html > Sent from the Electric Vehicle Discussion List mailing list archive at > Nabble.com. > _______________________________________________ > 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. 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/20150227/a481c785/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)
