The Korea Institute of Materials Science (KIMS, President Lee Jeong-hwan), a government-funded research institute under the Ministry of Science and ICT, has succeeded in demonstrating a fuel cell for an unmanned aerial vehicle that it developed itself, raising expectations that this will accelerate the development of long-range, long-distance unmanned aerial vehicles in the future.

The Korea Institute of Materials Science announced on the 13th that the research team led by Dr. Yang Cheol-nam of the Aerospace Materials Research Center of the Materials Digital Platform Research Headquarters had designed and manufactured a 1kW polymer electrolyte fuel cell, applied it to an unmanned aerial vehicle with a wingspan of 7.2m, and completed an aerial demonstration with a continuous flight time of 11 hours and a flight distance of 770km.

Internal combustion engines used in existing drones are advantageous for long-term flight, but they have many problems, such as noise, vibration, heat detection, air pollution caused by exhaust gas, and low energy efficiency. Recently, electric propulsion methods have become the trend, and lithium batteries, which are secondary batteries, are being used as energy sources for electric motors for drones. On the other hand, due to the low energy density of the battery, this also faces limitations in overcoming the short mission execution time.

To overcome the shortcomings of such engines and lithium batteries, the research team developed a new 1 kW fuel cell power source and applied it to an unmanned aerial vehicle by configuring it with a battery and hybrid power source. Through this, we developed a fuel cell power source for unmanned aerial vehicles capable of long-term flight and mission performance of over 12 hours, and completed airborne demonstrations.

The fuel cell and battery hybrid technology used this time is composed of a combination of 1 kW of fuel cell electrical output and a lithium polymer secondary battery. In order to respond to the rapid electrical output during takeoff and in the air of the drone, it is configured to produce a maximum output of over 4,200 W.

This technology is expected to be used for electric propulsion drones that require long-term flight as it can overcome the low energy density of secondary batteries applied to existing drones, and is therefore suitable for such drones. It is expected to be used for coastal lines, inland waters, environmental monitoring, and industrial infrastructure monitoring.

Currently, the technology for civilian fuel cell-powered drones is being jointly developed by Canada's BPS and FLY H2 Aerospace, which is supported by an African government, to fly 600 km for 9 hours. This achievement has been developed to a level that exceeds this goal.

The domestic market size for fuel cell-powered drone technology is still in its initial stages, with schools and venture companies importing overseas fuel cells and applying them to drones. Most of the development is being carried out at the level of being led by overseas fuel cell system companies, so the degree of freedom in development is low. This technology development is expected to contribute to not only the import substitution effect through localization but also technological independence through collaboration and joint development with domestic fuel cell-powered drone developers.

Yang Cheol-nam, the principal researcher and the head of the project, said, “By applying the developed fuel cell power source and flying for over 11 hours, we believe we have reached a world-class level for civilian use,” and “We will now continue to develop fuel cells capable of 24-hour continuous flight and conduct verification research on their application to unmanned aircraft, with the goal of reaching a level where they can be used for both civilian and military purposes.”

This research was carried out through the 'Development of Fuel Cell Power Sources for Aircraft and Demonstration Technology' project, a basic project of the Korea Institute of Materials Science, with support from the Ministry of Science and ICT.