Scientists in Australia have improved a technology that recycles waste heat into useable energy by using ionic liquids containing cobalt redox couples as the electrolytes in thermoelectric cells.
Thermoelectrochemical devices generate power when a temperature gradient exists across a redox couple. The power generated is not yet enough to use as a primary energy source, but thermoelectric cells are useful for harvesting waste energy from energy production.
Aqueous or organic solutions traditionally form the electrolyte in thermoelectrochemical cells. The volatility of water and most organic solvents restrict working temperatures as the solvent can evaporate, reducing the long term stability and power output of the cells. Ionic liquids have extremely low vapour pressures, because of the strong ionic interactions, so do not easily evaporate. Their low thermal conductivity compared to water also helps ionic liquids maintain the temperature gradient across the device.
Interested to know more?
Read the article in EES:
High Seebeck coefficient redox ionic liquid electrolytes for thermal energy harvesting
Theodore J. Abraham, Douglas R. MacFarlane and Jennifer M. Pringle
Energy Environ. Sci., 2013, Advance Article