Advancements In Cerium Oxide Thermal Switches

Researchers at the Research Institute for Electronic Science, Hokkaido University, have developed a thermal switch using cerium oxide, offering improved efficiency and sustainability.

Thermal switches control heat transfer electrically and are crucial for improving thermal management systems. However, electrochemical thermal switches have traditionally suffered from limited performance, hindering their widespread use in sectors like electronics, energy, and waste heat recovery.

A team of researchers at the Research Institute for Electronic Science, Hokkaido University, explored a new approach using cerium oxide (CeO2) thin films as the active material in thermal switches. This method offers a more efficient and sustainable solution. Their findings demonstrate that CeO2-based thermal switches can surpass previous performance benchmarks.

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The novel device demonstrates an on/off thermal conductivity ratio of 5.8 and a thermal conductivity (κ)-switching width of 10.3 W/m·K, setting a new benchmark for electrochemical thermal switches.

In its minimal state (off-state), the thermal conductivity is 2.2 W/m·K; in the oxidized state (on-state), it increases significantly to 12.5 W/m·K. These performance metrics remain stable after 100 cycles of reduction and oxidation, showcasing exceptional durability and reliability for long-term use in practical applications. A key advantage of this technology is cerium oxide, a widely available substance known for its cost-effectiveness and environmental sustainability.

Unlike traditional thermal switches that rely on rare and expensive materials, CeO2 provides an affordable and abundant alternative, lowering costs and reducing the environmental impact of thermal management solutions. This improves the technology’s efficiency, scalability, and potential for use across various industries.

The development of CeO2-based thermal switches marks a significant advancement in thermal management technology, with wide-ranging applications in fields like electronics cooling and renewable energy systems. These switches, used in thermal shutters and advanced displays, effectively regulate infrared heat transfer, improve waste heat recovery, and support energy-efficient systems.

Reference: Ahrong Jeong et al, High-performance solid-state electrochemical thermal switches with earth-abundant cerium oxide, Science Advances (2025). DOI: 10.1126/sciadv.ads6137