High-Performance Quasi-Solid Thermogalvanic Cells via Crown-Ether-Mediated Ion Migration.

Area of Science:

• Sustainable energy technologies
• Thermoelectric energy conversion
• Materials science

Background:

• Thermogalvanic cells (TGCs) offer promise for harvesting low-grade thermal energy.
• Achieving high output voltage in TGCs remains a significant challenge.
• The Soret effect and counterion roles are often overlooked in TGC optimization.

Purpose of the Study:

• To investigate methods for increasing thermovoltage in quasi-solid TGCs.
• To explore the impact of cationic complexing agents on TGC performance.
• To enhance the Seebeck coefficient by leveraging synergistic effects.

Main Methods:

• Utilized a quasi-solid thermogalvanic cell with K3Fe(CN)6/K4Fe(CN)6 redox couple.
• Introduced 18-crown-6, a cationic selective complexing agent.
• Analyzed the synergistic combination of the Soret and thermogalvanic effects.

Main Results:

• The introduction of 18-crown-6 significantly amplified cation thermodiffusion.
• The Seebeck coefficient of the TGC was boosted from 1.26 mV/K to 2.22 mV/K.
• Demonstrated a promising approach to enhance thermovoltage in TGCs.

Conclusions:

• The synergistic combination of Soret and thermogalvanic effects is key to boosting TGC performance.
• 18-crown-6 effectively enhances thermovoltage by amplifying the Soret effect.
• This study provides a viable strategy for advancing low-grade thermal energy harvesting technologies.