Speaking of Alpha

I was looking at Rechargable Licerion last year. It was 650 Wh/kg power density. I was (and Liceron's rivals were) hoping for one (1) kWh/kg. All of us want off lithium (and off cobalt, also associated). I figure I would do an update, on sodium.

Sodium / natrium is on the same Periodic Table column as lithium - except that it is cheaper. You "mine" sodium from brine or just scoop it off the shorelines of our evaporating lakefronts. Then fry the Na with some volts, vent the Cl (don't breathe it!) and store the metal in, I dunno, argon or something. So why don't we use it? Because it is also more chemically reactive. Apparently that's a problem on the negative-charge anode on the other side of the battery, usually carbon. We wanted something cheap right? Graphite (372 mAh/g) is fine for lithium but not for sodium. I don't suppose I can interest them in potassium...

If I be reading this aright, Shinichi Komaba's laboratory have a harder carbon with more storage at 478 mAh/g. Lithium batteries are up to 1430 Wh/kg as "standard" which I interpret, in their lab. That lab has got sodium at 1600. Not quite diamond. Yet.

They say they're looking into whether this can run in low temperatures, and if the input/output is viable. And if it will last as long as lithium before needing to be replaced. I'd personally worry more about higher temperatures; this Table column melts lower the more you go up in mass. Caesium melts like chocolate in your hand, before burning your hand and exploding.

I'd say longevity is key if we're talking car batteries. Although when it all gets cheap enough that might not matter for industry - just swap out the electrodes when you're done.

Cars might just be using graphene instead. Ryder's "dual carbon" from 2014 has been aimed at satellites and medicine, I guess why I've not heard from them. And, also, NAWA's graphene nanotubes.

There's still that capacitor-cell hybrid - CAPACITOR 1/6: 73 Wh/kg. I am told this competes with nickel-metal hydride. Neither is on par with the alkali batteries. NiMHs allow lower voltage without tinkering; the capacitor, here too, needs more tinkering. But capacitor overall life beats alkali. Also in a hybrid we only care to discharge the volts on startup and acceleration, which would certainly help a sodium battery in (what I expect is) its own shorter-than-lithium lifespan.