A High-Thermal-Insulation and Portable Microreactor for Integrating Widely Used Planar-Type SOFC and Enabling Handheld Power Generation

This paper represents a high-thermal-insulation microreactor that enables the integration of standard planar-type solid oxide fuel cells (SOFCs) for portable power generation. While planar SOFCs offer high efficiency and energy density, their use has been largely limited to stationary applications due to challenges in thermal management and slow start-up times. Our microreactor overcomes these barriers by providing an effective thermal insulation system, allowing SOFCs to operate efficiently in a compact, portable format. We designed a cantileveredstructure using yttria-stabilized zirconia (YSZ) to minimize thermal conduction and combined it with a multilayer insulation (MLI) system to suppress thermal radiation loss. This flexible cantileveredstructure prevents cracking under thermal stress and maintains high temperatures up to 700°C, ensuring reliable operation. Additionally, the MLI system features an inherent safety mechanism: when the insulation structure is damaged by a drilling, the loss of thermal insulation causes a rapid temperature drop, bringing the system below the hydrogen explosion threshold temperature within 5 minutes, thus preventing potential hazards. Our prototype successfully demonstrated handheld power generation using a planar metal-supported SOFC, achieving a rapid start-up time of just 5 minutes and driving a motor. This breakthrough offers a new platform for miniaturized SOFC technology, bridging the gap between stationary and portable energy solutions.