/“A lithium cell has no thermodynamic forcing function to move the ions back to the positive electrode. Stating this in the terms above - neither of the discharged or charge states are more stable than the other.”/
I’m not sure what you mean by this. Jay Whitacre (Materials Science, Carnegie Mellon): The phase change LiFePO4 to FePO4 occurs at 3.4V, redox reaction. During charging all lithium leaves the cathode, now have 3.4V driving Li back to the cathode when the charger is disconnected. - that's from the video I posted a link to after I posted the link to the video by Dahn. If a low enough resistance path for electrons to the cathode is provided, lithium will move back to the cathode to combine with electrons there and form LiFePO4, driven by the 3.4V chemical potential, with no external potential applied as during charging. Maybe by "stable" you mean this won't happen unless a low enough resistance path is provided, such as dendrites through the separator, conducting contamination on the cell packaging surface between electrodes, or an external wire connection. /"A lot of the effort that goes into forming the negative electrode has to do with physically arranging little plates of graphene so that there is a large percentage of the volume in this fortuitous geometry."/ No cells I know of are using graphene for one of the electrodes. People are experimenting with it, but no cells in production. Most use "specially formulated" graphite. Maybe that's what you meant since the carbon atoms bound in hexagons are arranged in sheets in graphite. Graphene is of course one of those single sheets, famously lifted with tape from a pencil mark when first studied, so I guess that is what you mean rather than an actual graphene electrode which would have quite different properties than graphite. -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Bicycle-battery-tp4676242p4676429.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)
