Thread: My battery idea

I had an idea for a new type of battery which recharges off of heat. I was wondering if it was possible. I haven't worked out any specifics yet, though.

A mixture of two chemicals has an endothermic reaction. The reaction produces two ionized chemicals (say salts) which are less stable than the first two chemicals. Metal plates can be used to draw electricity from the salts (actually drawing electrons from the plates, but whatever), causing the salts to recombine into the original two chemicals.

I had the idea while trying to figure out how to turn heat into electricity more efficiently. I realized that endothermic reactions are good at absorbing heat, though they don't release it as electricity.

Do you mean something like this? Donald Sadoway: The missing link to renewable energy | Video on TED.com

Originally Posted by adelady

Do you mean something like this? Donald Sadoway: The missing link to renewable energy | Video on TED.com

This is more about storing large amounts of energy. Also, it requires that you keep it hot in order to work.

I was hoping to make something that can recharge directly from heat, even at room temperature (or just above). It would have many uses, such as cooling (heat pump the air in your house, moving the heat to the battery). You could run the coolant in a nuclear plant near it, and capture energy more efficiently. You may even be able to produce geothermal power with it, as you can pump heat for 20% of the energy in the heat.

Well, there's a quite different idea being tried in a couple of places - distributed storage. In "inefficient" hot water units.

http://climatecrocks.com/2012/12/18/...in-smart-grid/

As for Sadoway's idea needing heating, he specifically states that it needs no external heating or cooling mechanism, the reactions do the work of keeping the electrolyte salt in liquid form all by themselves. My husband expressed some reservations about using magnesium in that configuration but he figures Sadoway and his team have worked that out, seeing as he mentioned using other elements and salts for the process.

Interesting idea. I'm more interested in efficiency in the production of the energy. How efficiently can you store and reclaim the energy in hot water? best I've heard of is a turbine at around 40%. Even then the temerature needs to be above room temp, so it is hard to use waste or radiant heat.

I'm more interested in efficiency in the production of the energy.

For this purpose, I'm pretty sure the best power source would be solar.

(Sigh. I miss my solar hot water system. At least the one in this house is almost 30 years old. When it dies, hopefully without any fuss, we'll have solar hot water again.)

If I could get this working, it should make solar thermal even more efficient. Also, solar is intermittent. A better way of converting heat to electricity could make liquid salt storage even better.

A battery is easy to make. Just take two Voltaire cells together. Battery means 'joining many as if to be one'.

That begs the question of how to make a Voltaire or fuel cell process that takes heat energy at the input, and electrical energy as the output.

Photosynthesis takes light and stores it as chemical energy.
Why won't it also take heat ?

Anyway, the question is definitely belonging to "chemistry" not electrics and electronics.
The most 'chemistry' electrical people do is "C+ O2 = CO2 + heat"