A battery based on solvation?

[Moreno]

Some solvation reactions are quite energetic (either endothermic or exothermic). Does it allow us to create an energy storage (similar to battery) in which energy would be generated when metal atoms pass to a solution through an ion-conducting membrane? If yes, how much energy may we expect to obtain and what about reverse-ability?

[John Cuthber]

Coupling the energy into an electrical form would be tricky (though possible).

This energy change is used - in a way- as a heat storage system

https://en.wikipedia.org/wiki/Sodium_sulfate#Thermal_storage

https://en.wikipedia.org/wiki/Thermal_energy_storage

It's possible to set up an electrical cell where the difference between the two electrodes is only the concentration of one material so you could have, for example a cell with dilute copper sulphate on one side and concentrated copper sulphate on the other  (and copper metal electrodes).

If you could use low grade heat and cold to crystallise the salt out of solution you could get some sort of heat powered battery.

I doubt it would be very efficient, but there may be some use for it somewhere.

Edited April 22, 2018 by John Cuthber