PowerSwitch

Ambri - has anyone heard of this technology?

https://youtu.be/ZRyo0Nr7CrY

Thoughts please.

Very doubtful indeed.

adam2 wrote: ↑15 Aug 2021, 13:14 Very doubtful indeed.

He’s a good salesman, that’s for sure but what do you see as the technology’s main downfall?

https://www.greentechmedia.com/articles ... ery-dreams

They have been around for a decade, failed to hit multiple delivery dates, and are chasing a market sector (small to medium static storage for 4 - 12 hours ) which has just about been sewn up by massive investment in Lithium chemistry.

High temperature (liquid sodium) sealed batteries sounds far too dangerous for domestic installations

Another battery chemistry trying to hit the jackpot.

I did not study the proposal in detail.
The phrase "disruptive investment" in the intro was enough to put me off.

High temperature batteries have been the "next big thing" for many years, but existing types of lead acid batteries and lithium batteries have most of the market.

Batteries involving highly reactive materials are inherently somewhat dangerous and these risks are multiplied by high operating temperatures. Maintaining this high operating in actual working conditions is also a greater challenge than suggested.
If daily cycling keeps the battery hot enough, then that suggests the need for active cooling if cycled several times daily.
Presumably heating would be required if the battery is to be left unused ?
Both active cooling and heating add cost and complexity.

Fair enough. I have to wonder where the energy comes from to maintain such high temperatures, with or without insulation. He’s talking 600/700 degrees.

It’s also one of those ‘too good to be true’ technologies. Cheap abundant materials, life measured in decades, easily recyclable.

The energy to maintain the high internal temperature comes from the fairly small but real losses in cycling the battery.
This sounds attractive but has a number of drawbacks.
Battery size is important, this technology does not scale up or down well. A smaller battery will be prone to getting cooler than desired, and a larger one be vulnerable to overheating.
It also presumes regular cycling, so wont work for standby applications as will cool down unless extra heat is supplied. If frequent cycling is required, then overheating is a risk without cooling.

I would not have such a battery in my home. Large lead acid battery banks make me a little nervous, large lithium batteries make me very nervous, and molten sodium or other reactive materials no way !

From what I can see it uses Antimony as one of the metals. I would guess that is fairly rare so excludes using this battery as grid scale storage. Calcium can be got from limestone at enormous energy cost to extract.

The only way I can see the benefits of a molten 'hot' battery is if it is at large scale and made of cheap, abundant and widely available materials.

Antimony is widely used , not least in lead acid batteries. That said, it is high on the list of elements critical to the global economy and of limited supply. The major mining sources are the usual suspects, China, Russia etc.

https://en.wikipedia.org/wiki/Antimony#Production

There is no free lunch when it comes to energy

Lead–antimony alloys used for the positive grids in lead–acid batteries for cycling service have generally used antimony contents of 4.5wt.% and above.

Compare with moving to a battery where 100% of one electrode is antimony would probably need a lot more antimony mining for grid storage applications.

Antimony melts at 630 C so will need a good container to withstand the heat but as the interviewee says it will not mind being used in hot places.

I would not put any of my own money into this project.

Other types of molten battery with more commonly available materials are...

Sodium-sulfur (or sulphur if you prefer). 80% efficiency and operating temperature of 250 to 350C

Sodium-nickel-chloride. No mention of efficiency and operating temperature over 250C. General Electric were looking at this and called it a Durathon battery but have since stopped for some reason. They were intended for use in mining vehicles (a notoriously secretive part of GE when I worked there).