The Korea Institute of Science and Technology (KIST) has developed a technology that allows electric cars to travel a distance of 800 kilometers on a full battery, the distance of a round trip from Seoul to Busan.
Korean scientists have conducted the world’s first road test of a magnesium-air battery vehicle. A magnesium-air fuel cell uses a magnesium anode and oxygen from air as a cathode. This can run a mid-to-large power system with high energy density demands, such as electric vehicles or emergency power sources.
Successful Road Test
The Korea Institute of Science and Technology announced a team has successfully completed the driving test of a vehicle powered by magnesium-air fuel cells. Dr. Cho Byung-won of the Center for Energy Convergence Research led the team. A magnesium-air battery holds five times more energy than a lithium-ion battery of equal size, and has a shorter recharging time. If a car powered by a magnesium-air battery is to travel at the same level as a conventional gasoline-driven vehicle, it should have a much greater energy density than the current electric vehicle models.
A magnesium-air battery is known to have a high energy density. However, its magnesium anode has low reaction efficiency and its air cathode has slow response speed. That means although a magnesium-air fuel cell is capable of storing much energy, there are limits to how that energy is converted into actual motor power. In order to address this problem, the KIST team employed various substances to change the chemical composition of the magnesium anode and air cathode and improve the reaction efficiency and speed. As a result, KIST’s magnesium-air battery has an energy discharge double that of a conventional battery.
The battery can be recharged in ten minutes by simply replacing a magnesium plate and the salt water electrolyte. Nonetheless, it is too early to say that a magnesium-air battery is ready to be fitted into electric vehicles. There are still many challenges to overcome before it can be fully commercialized. The biggest issue is cost. The fuel cost for the current model of magnesium-air battery car is triple that of a gasoline-driven car. Dr. Cho Byung-won says, although the fuel cost is quite high now, it will come down considerably and full commercialization will be possible once the battery technology and recycling techniques for magnesium hydroxide can be developed.