3 ms·
The difference in their geochemistry is substantial so even if chromium isn't technically that much more abundant, it's significantly easier to mine. The Gibbs
by throwup238 2y ago
The difference in their geochemistry is substantial so even if chromium isn't technically that much more abundant, it's significantly easier to mine.
The Gibbs free energy of formation for chromium oxides and chromite is much more negative than for lithium-bearing minerals so Cr compounds are thermodynamically favored to precipitate out of melts and solutions, forming minerals with high concentrations that then get pushed up by other processes. Li+, with its lone valence electron, just doesn't form strong bonds or highly stable mineral phases in comparison. On top of that the diffusion coefficients for Cr species in magmas and rocks are generally orders of magnitude lower than for Li. Cr gets locked into crystal structures early and stays put, while Li keeps migrating and diffusing in the form of water soluble minerals. There's also a whole biogeochemical cycle for Cr involving microbes that can concentrate it in sediments.
- pfdietz 2y agoChromium is also being looked at for resistive thermal storage, due to the stability properties you mentioned. Doped chromia (Cr2O3) bricks act as both thermal storage elements and resistive heating elements up to 1800 C. https://electrifiedthermal.com/ https://electrifiedthermal.com/ https://dspace.mit.edu/handle/1721.1/130800 https://dspace.mit.edu/handle/1721.1/130800
- brightball 2y agoThis is why I've been interested in the Graphene Aluminum batteries from GMG for so long. They are producing graphene in bulk without having to mine it. Aluminum is already extremely abundant as well. I'm very optimistic because these solve so many battery issues at the same time, heat, rapid charge, sourcing.
- bjconlan 2y agoOh wow this is great technology. (Also surprised that it's driven by the UQ/rio-tinto. Hopefully GMG will learn from the failures of Tritium on the business side of things (as they are from similar stock))
- brightball 2y agoYea, supposedly they are going to use the batteries for industrial and high power applications (like mining equipment) first before even looking at the EV market.
- KennyBlanken 2y agoAnother difference is that chromates are wildly toxic...
- throwup238 2y agoChromates are very rare in natural minerals and they’re mostly an industrial intermediate compound. Chromite is the common mineral converted to metal chromium for incorporation into alloys so the chromates are limited to the factory. Most other Cr bearing minerals contain chromium oxides. Other industrial lithium intermediates are also toxic, as is the concentrated brine it’s often extracted from. Since it’s concentration is so low, most lithium extraction is pretty nasty.
- hamilyon2 2y agoThis is now my favorite hacker news comment