Three-electrode cell calorimeter for electrical double layer capacitors.

Area of Science:

• Electrochemistry
• Materials Science
• Physical Chemistry

Background:

• Understanding heat generation in porous electrodes is crucial for energy storage devices.
• Distinguishing between heat produced during charging (anodic) and discharging (cathodic) cycles offers deeper insights.

Purpose of the Study:

• To develop and calibrate a calorimeter for measuring heat produced by porous capacitive working electrodes.
• To investigate the differences in heat production between cathodic and anodic processes.
• To correlate measured heat with electrical work to determine internal energy changes and understand the electrical double layer.

Main Methods:

• Construction of a calorimeter integrated with a three-electrode electrochemical cell.
• Utilizing a heat flux sensor to detect heat generated by the working electrode.
• Calibration of the heat sensor based on the net electrical work during charging-discharging cycles.
• Measurement of heat production in porous carbon electrodes within an aqueous salt solution.

Main Results:

• The calorimeter successfully detected differences in heat production between cathodic and anodic processes.
• Calibration allowed for the quantification of heat produced relative to electrical work.
• Measurements provided data on the internal energy changes of the working electrode as a function of applied potential.

Conclusions:

• The developed calorimetric method enables the study of energy transformations at the electrode-electrolyte interface.
• Insights into the potential energy and electric potential of ions within micropores were gained.
• This technique offers a pathway to better understand the electrical double layer structure and behavior in porous electrode materials.