Batteries That Perform Normally in the Stratosphere
LG Chem has successfully tested a high-altitude flight of an unmanned aerial vehicle powered by next-generation batteries.
LG Chem announced on Sept. 10 that an EAV-3 drone powered by its newly developed lithium-sulfur batteries successfully flew in the stratosphere.
The EAV-3, developed by the Korea Aerospace Research Institute (KARI), is a small drone that can fly for a long time on solar energy and batteries in the stratosphere, a layer of Earth's atmosphere at an altitude of 12 kilometers or higher. The drone charges itself with solar panels on its wings. It flies on solar cells and batteries during the day and uses batteries charged during the day at night. The EAV-3 has a wingspan of 20 meters. Its fuselage is nine meters long.
LG Chem conducted a flight test for about 13 hours from 8:36 a.m. to 9:47 p.m. at KARI’s Goheung Aviation Center on Aug. 30. LG Chem became the first Korean company to conduct such a test with lithium-sulfur batteries.
In particular, during the flight test, the EAV-3 flew at an altitude of 22 kilometers, the highest altitude for a domestically developed unmanned plane. In addition, it flew for seven of the total 13 hours of flight at an altitude of 12 km to 22 km in the stratosphere where normal aircraft cannot fly, maintaining stable output throughout the flight.
The flight test is quite meaningful as it has confirmed a stable charging and charging performance of lithium-sulfur batteries, which are a next-generation battery model, even in an extreme environment where temperature was minus 70 degrees Celsius and atmospheric pressure was one-25th of the ground level in the stratosphere.
Lithium-sulfur batteries are one of the next-generation batteries that will replace lithium-ion batteries, and are 1.5 times higher in energy density than lithium-ion batteries of the same weight as they use light materials, such as a sulfur carbon complex as the anode material and a lithium metal as the cathode material. They are lighter than lithium-ion batteries and do not contain rare metals, making them more competitive in price.
In addition, competition for development of lithium-sulfur batteries is fierce among countries around the world as they are considered a key component that determines the performance of electric vehicles, long-flight drones and personal aircraft.
LG Chem plans to produce upgraded lithium-sulfur battery prototypes that can power long-term flights for several days. In addition, the company plans to mass-produce lithium-sulfur batteries with energy density more than double that of current lithium-ion batteries after 2025.