Ionic Thermoelectric Effect within the Framework of Thermoelectricity.

Area of Science:

• Thermoelectricity
• Materials Science
• Electrochemistry

Background:

• The fundamental nature of the ionic thermoelectric (i-TE) effect is debated, with existing devices lacking interfacial contributions and no reported experimental evidence of the Peltier effect.
• A key question is whether the Seebeck, Peltier, and Thomson coefficients in i-TE systems satisfy the Kelvin relations.

Purpose of the Study:

• To systematically formulate the three thermoelectric effects in the i-TE context.
• To experimentally observe the ionic Peltier effect and verify the Kelvin relations in i-TE systems.

Main Methods:

• Systematic formulation of thermoelectric effects in i-TE systems.
• Experimental observation of the ionic Peltier effect.
• Development of an electromotive-force-based method for determining thermoelectric coefficients without direct heat-flux measurements.

Main Results:

• Experimental observation of a significant ionic Peltier effect with cooling power exceeding conventional electrolytes by over 2 orders of magnitude.
• Successful experimental verification of the Kelvin relations in i-TE systems using the new method.

Conclusions:

• The ionic thermoelectric (i-TE) effect is confirmed as genuine thermoelectricity.
• The study resolves fundamental questions regarding the i-TE effect and establishes its position within thermoelectricity.