Development of material design and tailoring physical properties for carbon nanotube yarns for high-efficiency thermoelectric generator

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H01371
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 21050:Electric and electronic materials-related
• Research Institution: Okayama University
• Principal Investigator: HAYASHI Yasuhiko 岡山大学, 環境生命自然科学学域, 教授 (50314084)
• Co-Investigator(Kenkyū-buntansha): 鈴木 弘朗 岡山大学, 環境生命自然科学学域, 助教 (20880553)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: カーボンナノチューブ / 熱電変換素子 / 炭素ナノ構造制御 / ドーピング技術

Outline of Final Research Achievements

Developed a technology to increase the yield of double-walled carbon nanotubes (DWCNTs), established structural control of residual amorphous carbon in the nano spaces of CNT-spinning yarns by dry spinning, in which long and dense CNT arrays are directly drawn and twisted, and combined CNT-spinning yarn with high-temperature treatment and doping technology in an original method to The n-type is stable at around room temperature. The results have resulted in a lightweight, flexible, and high-efficiency CNT-spun fiber thermoelectric conversion module using low-cost, environmentally-friendly materials with few resource constraints and have demonstrated thermoelectric conversion from the temperature difference between the human body temperature and the outside temperature. We discovered the possibility of replacing conventional inorganic materials such as bismuth-tellurium-based materials.

Free Research Field

ナノ材料・ナノ物性工学

Academic Significance and Societal Importance of the Research Achievements

ビスマス-テルル系をはじめとする無機系材料に代わり，資源の制約の少ない低コストで低環境負荷なフレキシブル・カーボンナノチューブ（CNT）紡績糸により，室温付近のわずかな温度差からの高効率電力変換する技術開発を行った．これまで困難であったCNTの層数制御，CNT紡績糸のナノ空隙に残留するアモルファス炭素の構造制御を確立し，CNT紡績糸熱電変換素子が実現でき学術的意義は大きい．CNT紡績糸熱電変換素子を用いることで，現在未利用で排熱されている膨大な量の200度未満の低温熱から効率的に電力に変換することができ，社会的意義は大きい．本研究の成果は，IoT機器・ウェアラブル機器への応用が期待される．