Effective use of thermal energy for energy conservation and carbon neutrality

60% of the primary energy supply is lost without effective utilization in the form of heat (waste heat). Furthermore, improving the efficiency of thermal management is necessary to achieve energy conservation in various devices, apparatuses, and processes. The development of innovative thermal management materials and thermal energy devices is essential for utilizing these waste heat and improving the efficiency of thermal management. Our team develops all aspects of thermal energy devices, including state-of-the-art materials, devices, and laboratory demonstrations by understanding the heat transfer phenomena from both theoretical and experimental perspectives to promote widely spread of the thermal energy devices. We equip our laboratory with advanced equipment for developing thermal energy devices.

Fundamentals of thermoelectrics: materials, module, and characterization

Thermoelectric technology enables the direct conversion between thermal and electrical energy. Our team focuses on achieving high efficiency in thermoelectric materials through the advanced control of heat and electrical transport with understanding the phenomenon from both theoretical and experimental perspectives. To construct high performance thermoelectric modules, we are developing electrode fabrication technology are developing for improving the thermal and electrical contacts between interfaces and investigating the degradation behavior for stability. Furthermore, we are interested in developing thermoelectric systems by integrating other thermal management technologies, such as thermal energy storage, heat transfer, and heat radiation. We also advance characterization technologies of thermoelectrics by conducting the interlaboratory testing in international framework to support fair thermoelectric market growth.

https://www.aist.go.jp/aist_e/list/latest_research/2013/20130515/20130515.html

https://www.aist.go.jp/aist_e/list/latest_research/2016/20160520/en20160520.html

https://www.aist.go.jp/aist_e/list/latest_research/2019/20191025/en20191025.html

https://www.aist.go.jp/aist_e/list/latest_research/2020/20200831/en20200831.html

https://www.aist.go.jp/aist_e/list/latest_research/2020/20201223/en20201223.html

Expanded applications of thermoelectrics power generation to vehicles, biochar economy, and space exploration

One important challenge is to expand the application of thermoelectrics power generation. For effectively use the large amount of heat wasted from vehicles and industrial processes, we develop advanced thermal management by integrating thermoelectrics with other thermal management technologies. To build a nature-positive economic, we design the thermal management of carbonization furnaces using thermoelectric power generation to increase the productivity of biochar and realize thermoelectric power generation. Furthermore, we develop a semi-permanent power supply system using thermoelectric power generation to expand the area of human activities to unexplored areas such as outer space. In addition, we have supported the establishment of Mottainai Energy Co., Ltd. (AIST startup company).

https://unit.aist.go.jp/ipaspro2023/tmb/en/interview24.html

Phase change materials for long duration energy storage and heat utilization with temperature fluctuation suppression

Phase change materials enable high density thermal energy storage near phase change temperature and repeatable use simply by exchanging heat. Our team focuses on developing waste heat recovery in the industrials with phase change materials, and the long duration energy storage for improving reliability of variable renewable energy. Furthermore, temperatures are stable during heat storage and heat release of phase change materials. We are interested in suppressing temperature fluctuation with phase change materials for innovate heat utilization.

Heat-resistant materials for NH₃-fuel internal combustion engines

Ammonia (NH₃) is promising next-generation carbon-neutral fuel because non-CO₂ emissions during in the combustion. Compared to hydrogen (H₂), which is also promising carbon-neutral fuel, the process for industrial mass production of NH₃ is well established. Moreover, simple liquefaction process of NH₃ allows ease of the storage and transportation. However, there has been little effort to use NH₃ fuel in power generation and internal combustion engines. In particular, there is little data on durability of heat-resistant materials used in internal combustion engines in high temperature and strong reducing atmosphere during NH₃ combustion. Our team evaluate the durability of various heat-resistant materials by exposing them in high-temperature and strong reducing atmosphere in NH₃ flow in the laboratory.

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