Molten Metal Batteries Yield 20 Times More Current Than Lithium-Ion

[AR-51]

Molten metal may not be what you want in your smartphone battery, but it turns out to work great for larger grid-scale batteries. MIT engineers have created devices that can provide up to 20 times as much current as lithium-ion batteries with the same electrode area, according to New Scientist.

http://www.popsci.com/technology/article/2010-04/molten-metal-batteries-could-store-extra-juice-power-grid

[KarenRei]

Very cool. Er, hot. ;) I see a lot of interesting applications for molten metal and molten salt batteries for grid storage. Maintaining heat isn't an issue there, they tend to have long cycle lifes, and they tend to be made from relatively cheap materials.

This (http://web.mit.edu/newsoffice/2009/liquid-battery.html) older article doesn't list the specific metals, but it otherwise gives a lot of additional info.

Looks like bulk magnesium is under $2 a pound. Bulk antimony appears to be closer to $3 a pound. Pretty cheap if the vats are just bulk raw metals... The middle layer is a magnesium antimony salt; doesn't say specifically which salt (wouldn't be surprised if it was a sulfide, though).

Sounds like a vat "the size of a shipping container" (8'x8'x20': 1280'^3) does 1MW and "several" MWh. We're probably dealing with something like 200 pounds per cubic foot on average. So ~250k pounds. So ~$650k worth of metal for "several" MWh. Sounds like lead-acid prices and energy densities. But I'd imagine much better cycle life and other properties.