A research team from UNIST’s School of Energy and Chemical Engineering has developed an advanced electric vehicle (EV) battery technology which is deemed to be more energy-efficient as compared to gasoline-driven engines. With the new technology, battery packs can simply be replaced without the need of charging them. According to the researchers, the new approach will ultimately improve the problems associated with existing EV battery technology such as slow charging. The breakthrough led by Professor Jaephil Cho is detailed in a study paper and featured in Nature Communications, an academic journal. The researcher discussed that the new technology for Aluminum-air Batteries offers high-energy density power sources and outperforms the currently used lithium-ion batteries (LIB) in various terms including cost, safety, energy density, and cycle life. Further, it has little or no risk of catching fire and explosion.
Primary cells such as aluminum-air batteries cannot be recharged through conventional process. Using this concept, the researchers developed a new type of aluminum-air flow battery for electric vehicles which when applied, produces electricity by replacing electrolyte and aluminum plate. Energy density of aluminum has shown to be superior to that of gasoline of the same weight.
Professor Cho explained that aluminum-air flow battery is capable of exhibiting energy density higher than 2,500 Wh/Kg while the energy density of gasoline limits to just 1,700 Wh/Kg. This means, a battery build with a Kg of aluminum will enable an electric car to run about 700 Km, he added.
Metal-air batteries such as aluminum-air batteries have been gaining much attention as next-generation batteries. They produce electricity from the reaction of metal (aluminum) with oxygen in the air and exhibits higher density than the conventional LIBs. In addition, batteries that use aluminum are cheaper, lighter, and have greater capacity as compared to LIBs. Although aluminum-air batteries are considered to have highest energy densities, they are not broadly used due to high cost anode and byproduct removal.
To overcome this issue, the research team created a flow-based aluminum-air battery that can continuously circulate the electrolytes while preventing the side reactions in the cell. For oxygen reduction reaction, they prepared a silver-manganese oxide based catalyst and found that the silver atom migrates into crystal lattice and creates abundant surface dislocations while rearranging the manganese oxide structure.
Owing to improved energy density and longevity, the researchers believe that aluminum-air flow battery (AAFB) system could bring more electric vehicles on the road that are lightweight and has better range.