Control of Liquid-Absorbing Structure to Improve Performance of Transpiration-Type Thermoelectric Power-Generating...

Area of Science:

• Materials Science
• Energy Harvesting
• Nanotechnology

Background:

• Carbon nanotube composite paper (CNTCP) enables thermoelectric power generation.
• CNTCP utilizes capillary action and heat of vaporization for spontaneous temperature differences.
• Previous CNTCP had limitations in controlling generated temperature gradients.

Purpose of the Study:

• To improve transpiration-type thermoelectric power-generating paper (t-TEPGP) by controlling water absorption.
• To investigate the effect of manufacturing processes (hot pressing vs. oven drying) on CNTCP water absorption and thermoelectric performance.
• To enhance the electromotive force (E.M.F.) generated by t-TEPGP.

Main Methods:

• Manufacturing CNTCP with varied water absorption capacities using hot pressing and oven drying techniques.
• Measuring the spontaneous temperature difference generated by the modified CNTCP.
• Quantifying the electromotive force (E.M.F.) produced by the t-TEPGP samples.

Main Results:

• Successfully controlled water absorption by altering the manufacturing process.
• Achieved a maximum temperature difference of 0.6 °C and an E.M.F. of 47 μV from a single sample, approximately double previous results.
• A three-pair sample generated an E.M.F. of 193 μV with a 1.2 °C temperature difference.

Conclusions:

• The developed t-TEPGP demonstrates enhanced thermoelectric performance through controlled water absorption.
• Manufacturing process modifications offer a viable method to tune the performance of CNTCP for energy harvesting.
• This technology presents a promising avenue for sustainable, self-powered devices.