Thermocells Driven by Phase Transition of Hydrogel Nanoparticles

Benshuai Guo, Yu Hoshino, Fan Gao, Keisuke Hayashi, Yoshiko Miura, Nobuo Kimizuka, Teppei Yamada

Research output: Contribution to journalArticlepeer-review

46 Citations (Scopus)


Thermoelectric conversion of low temperature, delocalized, and abundant thermal sources is crucial for the development of the Internet of Things (IoT) and/or a carbon-free society. Thermocells are of great interest in thermoelectric conversion of low-temperature heat due to the low cost and flexibility of components. However, significant improvement of the conversion efficiency is required for the practical use of the cells. Here, we report thermo-electrochemical cells driven by volume phase transition (VPT) of hydrogel nanoparticles (NPs). Entropically driven VPT of poly(N-isopropylacrylamide) NPs containing carboxylic acids and amines generates a pH gradient of up to 0.049 and -0.053 pH K-1, respectively, around physiological temperature. The pH gradient triggers the proton-coupled electron transfer (PCET) reactions of quinhydrone on the electrodes, resulting in the highly efficient thermoelectric conversion with a Seebeck coefficient (Se) of -6.7 and +6.1 mV K-1. Thermocells driven by phase transition of hydrogels provide a nontoxic, flexible, and inexpensive charger that harvests carbon-free energy from abundant energy sources such as solar, body and waste heat.

Original languageEnglish
Pages (from-to)17318-17322
Number of pages5
JournalJournal of the American Chemical Society
Issue number41
Publication statusPublished - Oct 14 2020

All Science Journal Classification (ASJC) codes

  • Catalysis
  • General Chemistry
  • Biochemistry
  • Colloid and Surface Chemistry


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