Monday, December 10, 2018

A battery made of molten metals

New battery may offer low-cost, long-lasting storage for the grid.

A novel rechargeable battery developed at MIT could one day play a critical role in the massive expansion of solar generation needed to mitigate climate change by midcentury. Designed to store energy on the electric grid, the high-capacity battery consists of molten metals that naturally separate to form two electrodes in layers on either side of the molten salt electrolyte between them. Tests with cells made of low-cost, Earth-abundant materials confirm that the liquid battery operates efficiently without losing significant capacity or mechanically degrading — common problems in today’s batteries with solid electrodes. The MIT researchers have already demonstrated a simple, low-cost process for manufacturing prototypes of their battery, and future plans call for field tests on small-scale power grids that include intermittent generating sources such as solar and wind.

Read more:


TSE said...

That's one of them high tech thingies with a lot of propositions placed before you can even afford to buy and own one....

And I can guarantee you - you can't.

How about something simpler and more elegant?

The cheapest way to store moderately high temperature sensible heat (500-700C) is in pebble bed storage. Not many things are cheaper than crushed rock. The cheapest way to contain the pebble bed is with gravity, no tank needed. The cheapest good insulation is volcanic cinder, also contained by gravity. Add in a stainless steel foil layer to separate the cinder from the pebble bed and a cross-linked polyethylene tarp to keep the rain off the cinder, use air as the heat transfer medium and you get storage costs in the range of $2-$3 per net kWhe of storage capacity. The “Holy Grail” of battery storage is $100 per kWh, so the advantage of heat storage is obvious. The more heat storage needed, the more the system efficiency, since scale effects reduce the ratio of surface area to volume as the storage system gets larger. Seasonal storage of heat with low percentage loss is very possible.

I’ll admit that white hot silicon can offer a better thermodynamic efficiency than 600 degree C rock, but just think of the capital costs involved in storing and handling such a material! Sometimes a lower-tech solution can far out perform stuff that needs rocket science to build. Since most of CSP is unchanged since the work of Frank Shuman in 1912, I often wonder what could have happened if we had ever taken the issues of fossil fuel depletion and carbon pollution seriously. But we didn’t, we won’t and now it’s too late.

OrbsCorbs said...

People use pebbles or crushed rock as mulch in plant beds. That just fries the plants.