Highly Efficient Thermal-Electric Energy Conversion Mechanism Utilizing Phase Transitions in Solid Materials

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H01822
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 29030:Applied condensed matter physics-related
• Research Institution: Tokyo University of Marine Science and Technology
• Principal Investigator: Shibata Takayuki 東京海洋大学, 学術研究院, 助教 (30758264)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 三次電池 / エネルギーハーベスティング / プルシャンブルー類似体 / 相転移 / 放射光X線 / 紫外－可視吸収スペクトル / 赤外吸収スペクトル

Outline of Final Research Achievements

A tertiary battery generates electricity by changing the temperature of the environment surrounding the battery. If a material exhibiting a phase transition is used for the electrode, a large potential change is generated, allowing for the development of a highly efficient tertiary battery. To determine the design guidelines, it was necessary to understand the phase transition behavior of electrode materials. As a result, it was found that the charge-transfer phase transition occurs almost everywhere with respect to the Na concentration in the cobalt-manganese Prussian blue analogue, which exhibits a charge-transfer phase transition just above room temperature. In addition, we proposed theoretical equations for thermal voltage and discharge capacity, which are the performance indexes of tertiary batteries, and found that the experimental results can be reproduced by these equations.

Free Research Field

応用物理学一般

Academic Significance and Societal Importance of the Research Achievements

本研究では、身近な環境の温度変化で熱ー電気エネルギー変換が可能な三次電池の性能向上を目指すため、電極材料の物性評価を行った。また、三次電池の性能を最大限引き出すための方法を検討し、実験結果を理論的に表現することを可能とした。これらの成果は、今後の三次電池開発の指針を与えるもので、学術的意義が高いものと考える。また、これらの成果を受け、実際に三次電池の熱起電力の増大にも成功しており、未利用熱の社会還元への寄与という意味でも、社会的意義も大きいと考える。