Hellscape_Instigator t1_ix2b0hx wrote on November 20, 2022 at 4:52 AM

Weren’t molten sodium batteries already a thing and proven to be really bad convenience-wise. Like, I think the Th!nk City had a molten sodium battery and they later changed to Lithium Ion because if you left the car sitting unplugged for too long (even if it had plenty of range) the battery would solidify and permanently kill itself.

Of course, the main claim of this article was that it’d be useful for grid backups. It makes sense in theory. The battery would only be “unplugged” when it’s being discharged and used, but I still can’t help but feel like a battery that has a time limit alongside a capacity limit is a bad idea, especially in an emergency situation. Also, places with extremely cold climates or bad winters would be even worse off.

Oddyssis t1_ix2g07e wrote on November 20, 2022 at 5:44 AM

Seems like that's a matter of just building the battery so it turns on if it's ever getting too cool to run up some heat. Not efficient for things that might sit inactive for a while but I'm sure it has uses

mludd t1_ix2rcll wrote on November 20, 2022 at 8:10 AM

> Weren’t molten sodium batteries already a thing and proven to be really bad convenience-wise.

Yup, Aging Wheels did a video on the Th!nk City and mentioned this issue. Basically, if you left your Th!nk City unplugged overnight the battery would freeze and stop working until you re-melted the sodium (by charging it).

So usable in warmer climates if you regularly plugged it in but otherwise a bit of a hassle.

AndreLeo t1_ix32j6d wrote on November 20, 2022 at 10:53 AM

Slight correction, it’s less about melting the sodium than melting the salt (the electrolyte) here. Whilst the battery could perfectly handle the electrodes in a solid state, unfortunately most solids conduct ions barely at all - which also is the reason why developing solid state batteries is so hard

Just_wanna_talk t1_ix3ulpk wrote on November 20, 2022 at 3:34 PM

I feel like it would be more practical to use these batteries as part of a renewable energy power grid for storage for night time use and times with low wind. Need giant storage capacity for cheap and it will likely be more feasible than lithium.

Teripid t1_ix2ip3z wrote on November 20, 2022 at 6:16 AM

Right and the cell size is pretty irrelevant since that doesn't impact usage just replacement, etc.

Main use would likely be supporting large scale solar / wind that can suffer outages but this specific usage and tech seems to be really early.

Cold climate likely isn't much more than extra cost for insulation or external structure.

TristesteLivet t1_ix2w3o5 wrote on November 20, 2022 at 9:18 AM

The engineers from Think still think of salt batteries fondly because of how stable it was compared to other battery chemistries. Made it a lot safer if you crashed.