Flexible Thermoelectric Polymers and Systems

Library of Congress Cataloging‐in‐Publication Data

Names: Ouyang, Jianyong, author.

Title: Flexible thermoelectric polymers and systems / edited by Jianyong Ouyang, National University of Singapore.

Description: 1st edition. | Hoboken, NJ : Wiley, 2022. | Includes index.

Identifiers: LCCN 2021033949 (print) | LCCN 2021033950 (ebook) | ISBN 9781119550709 (hardback) | ISBN 9781119550723 (ebook) | ISBN 9781119550686 (epdf) | ISBN 9781119550631 (epub)

Subjects: LCSH: Thermoelectric apparatus and appliances–Materials. | Thermoresponsive polymers. | Flexible electronics.

Classification: LCC TK2950 .O987 2022 (print) | LCC TK2950 (ebook) | DDC 621.31/243–dc23

LC record available at https://lccn.loc.gov/2021033949LC ebook record available at https://lccn.loc.gov/2021033950

Cover Design: Wiley

Cover Image: © Ajwad Creative/Getty

Shanshan ChenSchool of Energy & Power Engineering State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing P. R. China

Xinyi ChenKey Laboratory of Textile Science & Technology of Ministry of Education College of Textiles Donghua University Shanghai China

Hanlin ChengDepartment of Materials Science and Engineering National University of Singapore Singapore Singapore

Ming Hui ChuaInstitute of Materials Research and Engineering (IMRE) Agency for Science, Research and Technology (A*STAR) Singapore Singapore

Minzhi DuKey Laboratory of Textile Science & Technology of Ministry of Education College of Textiles Donghua University Shanghai China

Zeng FanSchool of Physics Dalian University of Technology Dalian P. R. China

Xue HanKey Laboratory of Textile Science & Technology of Ministry of Education College of Textiles Donghua University Shanghai China

Lin HuChina‐Australia Institute for Advanced Materials and Manufacturing Jiaxing University Jiaxing P. R. China

Fengxing JiangFlexible Electronics Innovation Institute Jiangxi Science and Technology Normal University Nanchang P. R. China Department of Physics Jiangxi Science and Technology Normal University Nanchang P. R. China

Yuanyuan JingKey Laboratory of Textile Science & Technology of Ministry of Education College of Textiles Donghua University Shanghai China

Meng LiMOE Key Laboratory of Low‐grade Energy Utilization Technologies and Systems CQU‐NUS Renewable Energy Materials & Devices Joint Laboratory School of Energy & Power Engineering Chongqing University Chongqing P. R. China

Zaifang LiChina‐Australia Institute for Advanced Materials and Manufacturing Jiaxing University Jiaxing P. R. China

Peipei LiuDepartment of Physics Jiangxi Science and Technology Normal University Nanchang P. R. China

Congcong LiuFlexible Electronics Innovation Institute Jiangxi Science and Technology Normal University Nanchang P. R. China

Yang LiuMOE Key Laboratory of Low‐grade Energy Utilization Technologies and Systems CQU‐NUS Renewable Energy Materials & Devices Joint Laboratory School of Energy & Power Engineering Chongqing University Chongqing P. R. China

Baoyang LuFlexible Electronics Innovation Institute Jiangxi Science and Technology Normal University Nanchang P. R. China

Chunhong LuKey Laboratory of Textile Science & Technology of Ministry of Education College of Textiles Donghua University Shanghai China

Jianyong OuyangDepartment of Materials Science and Engineering National University of Singapore Singapore Singapore

Lujun PanSchool of Physics Dalian University of Technology Dalian P. R. China

Yue ShuMOE Key Laboratory of Low‐grade Energy Utilization Technologies and Systems CQU‐NUS Renewable Energy Materials & Devices Joint Laboratory School of Energy & Power Engineering Chongqing University Chongqing P. R. China

Kuan SunMOE Key Laboratory of Low‐grade Energy Utilization Technologies and Systems CQU‐NUS Renewable Energy Materials & Devices Joint Laboratory School of Energy & Power Engineering Chongqing University Chongqing P. R. China

Ady SuwardiInstitute of Materials Research and Engineering (IMRE) Agency for Science, Research and Technology (A*STAR) Singapore Singapore

Zhenghong XiongMOE Key Laboratory of Low‐grade Energy Utilization Technologies and Systems CQU‐NUS Renewable Energy Materials & Devices Joint Laboratory School of Energy & Power Engineering Chongqing University Chongqing P. R. China

Jianwei XuInstitute of Materials Research and Engineering (IMRE) Agency for Science, Research and Technology (A*STAR) Singapore Singapore

Jingkun XuFlexible Electronics Innovation Institute Jiangxi Science and Technology Normal University Nanchang P. R. China

Yuanyuan ZhengKey Laboratory of Textile Science & Technology of Ministry of Education College of Textiles, Donghua University Shanghai China

Yujie ZhengSchool of Energy & Power Engineering State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing P. R. China

Fengling ZhangDepartment of Physics Chemistry and Biology Linköping University Linköping, Sweden

Kun ZhangKey Laboratory of Textile Science & Technology of Ministry of Education College of Textiles Donghua University Shanghai China

Yinhua ZhouWuhan National Laboratory for Optoelectronics, and School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan Hubei China

Yongli ZhouMOE Key Laboratory of Low‐grade Energy Utilization Technologies and Systems CQU‐NUS Renewable Energy Materials & Devices Joint Laboratory School of Energy & Power Engineering Chongqing University Chongqing P. R. China

Thermoelectric materials are interesting because they can be used to directly convert heat into electricity. Some conductive materials can exhibit a notable voltage under temperature gradient, that is, the Seebeck effect. The thermovoltage with respect to the temperature is called Seebeck voltage. The Seebeck voltage can be positive or negative depending on the accumulation of the charge carrier(s) at the two ends under temperature gradient. A p ‐type thermoelectric material exhibits a positive Seebeck voltage, while an n ‐type thermoelectric material has a negative Seebeck voltage. High Seebeck coefficient has been observed on semiconductors and semimetals. The value is related to the relative position of the Fermi level from the top of the valence band or the bottom of the conduction band or simply the doping level since a change in the doping level can shift the Fermi level. Apart from the Seebeck coefficient, a high electrical conductivity is also required for efficient thermoelectric conversion. However, a good thermoelectric material should have a low thermal conductivity so that more heat can be utilized for power generation. Thermoelectric materials are used as the active materials of thermoelectric generators. They can be used in thermoelectric cooling systems in terms of the Peltier effect as well.

The conventional thermoelectric materials are inorganic semiconductors or semimetals such as Bi 2Te 3and its derivatives or analogues. These materials can exhibit high Seebeck coefficient and high electrical conductivity, but they also have a problem of high thermal conductivity. Hence, great effort has been made on lowering the thermal conductivity of inorganic thermoelectric materials besides on the improvement in the Seebeck coefficient and/or electrical conductivity. Consider for practical application, inorganic thermoelectric materials are usually brittle, and thus they are not suitable for flexible thermoelectric systems.