TY - JOUR
T1 - High Positive Seebeck Coefficient of Aqueous I-/I3-Thermocells Based on Host-Guest Interactions and LCST Behavior of PEGylated α-Cyclodextrin
AU - Liang, Yimin
AU - Ka-Ho Hui, Joseph
AU - Morikawa, Masa Aki
AU - Inoue, Hirotaka
AU - Yamada, Teppei
AU - Kimizuka, Nobuo
N1 - Funding Information:
This work was partly supported by JST PRESTO (Grant Number JPMJPR141D), Japan, and JSPS KAKENHI (Grant Numbers JP25220805, JP17H03046, JP26708007, JP19H05061, JP20H05676, 20H02714, 20K21176, and JP16H06513) (Coordination Asymmetry), the Ogasawara Foundation for the Promotion of Science & Engineering, Sekisui Chemical Co. Ltd., Hitachi Foundation, and the Asahi Glass Foundation.
Funding Information:
The authors gratefully acknowledge the support of ITC measurement from Dr. Yu Hoshino (Department of Chemical Engineering, Graduate School of Engineering, Kyushu University).
Publisher Copyright:
©
PY - 2021/5/24
Y1 - 2021/5/24
N2 - The high Seebeck coefficient of an I-/I3- thermocell was achieved by introducing host molecule PEGylated α-cyclodextrin (TEG-α-CD), which showed thermally induced phase transition. The host captures I3- at the cold side of the thermocell, which increased Se up to +2.4 mV/K. Notably, the maximum Se value of +4.2 mV/K was observed in the temperature range between 31 and 37 °C, which was achieved as a consequence of the phase transition between a hydrophilic phase to a hydrophobic phase. At the lower temperature side of the thermocell, the host effectively captures the I3- anion. Meanwhile, microphase separation of TEG-α-CD occurred at the higher temperature side, which promoted the dissociation of I3-. This resulted in a large concentration gap of electrochemically active I3- ions in between the electrodes. The power density determined for the thermoelectric cell was doubled in the presence of TEG-α-CD. This result provides a practical means to design n-type thermocells showing positive Se, only from low-molecular-weight compounds.
AB - The high Seebeck coefficient of an I-/I3- thermocell was achieved by introducing host molecule PEGylated α-cyclodextrin (TEG-α-CD), which showed thermally induced phase transition. The host captures I3- at the cold side of the thermocell, which increased Se up to +2.4 mV/K. Notably, the maximum Se value of +4.2 mV/K was observed in the temperature range between 31 and 37 °C, which was achieved as a consequence of the phase transition between a hydrophilic phase to a hydrophobic phase. At the lower temperature side of the thermocell, the host effectively captures the I3- anion. Meanwhile, microphase separation of TEG-α-CD occurred at the higher temperature side, which promoted the dissociation of I3-. This resulted in a large concentration gap of electrochemically active I3- ions in between the electrodes. The power density determined for the thermoelectric cell was doubled in the presence of TEG-α-CD. This result provides a practical means to design n-type thermocells showing positive Se, only from low-molecular-weight compounds.
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U2 - 10.1021/acsaem.1c00844
DO - 10.1021/acsaem.1c00844
M3 - Article
AN - SCOPUS:85106407143
SN - 2574-0962
VL - 4
SP - 5326
EP - 5331
JO - ACS Applied Energy Materials
JF - ACS Applied Energy Materials
IS - 5
ER -