Wednesday, March 28, 2012

Another Super Battery - Liquid Metal or just Hot Air?


Liquid Metal 
Hot Air?

Although I am jaded by, and highly sceptical about, all reports of new super-duper batteries and mega ultra capacitors that all will "revolutionise our lives and save the world",  I was nevertheless taken by the following report and my dim embers of interest were blown into life yet again. Call me a sucker, or a damn fool if you like!

This one is about Prof. Donald Sadoway of MIT who had a Eureka moment in his work on a high capacity battery.  Looking at aluminium electrolysis smelting, where typically 350,000 Amps are passed through the material in a process identical to that which takes place in every electro-chemical battery, he came up with the idea of a Liquid Metal Battery.

Essentally a battery that could handle massive current and operate at very high temperatures, have a very high storage capacity, be made from generally available and inexpensive materials, and not be a danger to the environment. Bit of a tall order?

Prof. Sadoway has been promoting his idea by doing a lot of lecturing and has a very good presentation on TED:

Liquid Metal Battery Inc., the development company formed to take the project to a market level, has accepted investment funding from Bill Gates' venture capital company and from another corporation involved in oil.

Mr. Microsoft Invests

Bill Gates has previously demonstrated concern and interest in clean energy and climate. Last year alone, he put money into five battery-related ventures. The US government agencies have also put quite a few millions into battery research. Slow old business - and no guarantees at the end of it. Not a place to gamble on. On the other hand, if one battery design makes it all the way, it would be Microsoft etc. all over again for the investors.

The photo above shows a cut-away mock-up of a prototype to demonstrate the general layout of a liquid-metal battery cell.

The red layer is the heavy liquid metal cathode at the bottom Antimony in the proto-types. I imagine that gravity must be a factor in these cells, and therefore they need to be in fixed locations.

Yellow is the molten salt electrolyte layer, and the green is the less dense Magnesium anode. The container is surrounded by an insulator material.

Above photo shows one of the lab prototypes, a 16" diameter pizza sized unit packing a capacity of 1Kw hour - not bad!!

Research on the all-liquid battery approach has been going on for about five or six years and Prof. Sadoway said the group has so far met the technical and cost milestones set out by investors.

Prof. Sadoway has also said that the real task in hand is to get (total installed costs) down below $250 a kilowatt-hour, and added that they will have their work cut out for them to reach that goal, but that he was "guardedly optimistic".

Time Scale

This sounds as if the time scale will be years rather than months. Thing is, that long development time-scales, on average, tend to equal little or no end result - we have way too many examples of this fact.  I really do hope that this one is different, and that it gets industrial scale working examples up and running in short time. Good luck guys.


1 comment:

dayzero said...

I've backed a project [on kickstarter dot com] to make a small unit which will retail at [hopefully] $100
that replicates the 'stirling' engine of the, erm, 1800's which is a difference engine.
You stick one end in your burner [or any other heat source], and it chugs out 1kW p/h. 24kW p/d.

But we will, of course, be needing some batteries to store all that extra power.

With this little beauty and solar,
I'm not sure we'll be needing much more. Depends on ones power useage I guess. Ive just started refitting my home with LED lights on a 12v system. Much better than mains power. Works a treat. Dimmer switches arriving form Hong Kong imminently.

Most recent update on the Volo Engine linked here;

All the best!