ORNL scientist on reducing battery costs
posted on
Sep 23, 2014 10:22AM
Hydrothermal Graphite Deposit Ammenable for Commercial Graphene Applications
Dr. Daniel is the scientist listed on the two studies being carried out in which Zenyatta's is participating and presumably providing Albany graphite material. A couple of things struck me about this very simple and easy to read abstract.
http://www.naefrontiers.org/File.aspx?id=45598
1) there is no mention of materials including graphite as being drivers of cost and therefore targets for cost reduction.
2) the key point in this article is the switch to aqueous process from the use of solvents in making the slurrys used for producing the electrodes including the anode and graphite.
One key property that has been noted for hydrothermal graphite is the crystallinity which gives rise to a number of important properties.
a) low resistivity and conversely high conductivity (ideal for battery use)
b) high density (also desireable for battery use), Albany graphite density = 2.25g/cc which is ideal.
c) particle size (ZENs has a volumetic mean of 18 microns which is basically ideal for battery use). So no need for sphericalization and potatoes. This a major point of misunderstanding I feel. Flake graphite needs to be large so that it can be ground to about 20 microns and then potato shaped. This process results in up to 70% loss. Albany graphite is already the right size and has low resistivity.
d) forming and shaping (the high crystallinity of hydrothermal graphite makes it the easiest to form and shape without binders. Binders reduce the charge density in batteries and it is ideal if they can be reduced or left out)
TP