Sumitomo's New Molten Salt Battery

[sanman]

Sumitomo Corp and Kyoto University have jointly come up with a new sodium-based molten salt battery which is claimed to have twice the energy density of Lithium-ion batteries, at only 10% the material cost. They hope to bring it to market in 2015.

http://www.ytwhw.com/2011/0304/New-Sumitomo-Electric-Battery-90-Cheaper-Than-Lithium-Ion-Nikkei.html

Molten salt battery technology has been around for decades, however a key constraint was the requirement of a high operating temperature, of around 300ºC and above. The new battery has a melting point of just 57ºC, and an operating temperature of 80ºC.

This is still considered too high for personal vehicles and electronics, with the best suitability for continuous power applications such as home power and buses. One can imagine how such a battery system could buffer against brown-outs or load-shedding from a deficient electrical grid, or even buffer solar and wind power collection between peak and lean periods. Hopefully Sumitomo and KU will continue their search for even lower operating temperature formulations.

But what if you really did want to use this battery for an electric car? What would you combine it with and how, in order to leverage this battery most effectively for good vehicle performance?

Fortunately, waste heat seems to be the easiest thing for any engine to generate, which is what this battery most needs to achieve its operating temperature. Perhaps vacuum insulation or even aerogel could also keep the battery from losing heat. Would a microturbine be useful for producing both electricity to drive electric motors, as well as heat to sustain battery operation? What would be the best way?

 

[Lok]

Sumitomo Corp and Kyoto University have jointly come up with a new sodium-based molten salt battery which is claimed to have twice the energy density of Lithium-ion batteries, at only 10% the material cost. They hope to bring it to market in 2015.

Any predictions on Wh/kg? As it is the most important value for batteries IMO.

A setup to keep it hot is easy enough, the problem seems to be preheating, which will seriously affect performance. That energy will be lost again and again, at every start-up.

And even with good insulation, much will be lost, as all batteries need to carry electrical current through conductors which are thermal conductors too.

Don't know the layout of the battery but mostly there are very few batteries that work in airtight conditions, most leaking a gas of some sort, that will be a challenge to insulate thermally. Too much insulation and you will need a cooling system, or something that releases heat after working temp is achieved.

While the concept might be light and cheap, there will be added weight and cost from maintaining working conditions.

Let's hope for a better salt in the near future.