Thermoelectric energy conversion based on the Seebeck
effect holds
great potential for effectively mitigating economic and environmental
impacts. In contrast to conventional solid semiconductor thermoelectric
cells, liquid thermogalvanic cells (TGC) have 1 order of magnitude
higher thermopower of approx. 1 mV K–1. However,
very limited redox pairs were reported to generate outstanding thermopowers
for TGCs. Therefore, achieving n–p or p–n conversion
for expanding redox couples is highly promising to resolve the challenge
for TGCs. Herein, the p–n conversion of the I–/I3
– TGC with high thermopowers was
accomplished by employing easily prepared and scalable thermoresponsive
diblock copolymers. By combining the distinct anion–polymer
interaction and the micellization of the diblock copolymer, variable
concentrations of ions invert the redox reactions at hot and cold
sides. As a result, the efficient p–n conversion and enhanced
power conversion efficiency was achieved for the I–/I3
– TGC with the introduction of copolymers.
Building on the different ion–polymer interactions, the strategy
developed in this work is also highly expected to extend to other
electrochemical processes and applications.