Scientists in South Korea have developed a unique electric vehicle battery that enables drivers to simply have their battery packs replaced instead of charging them, avoiding the slow charging problems drivers have with existing EV battery technology.



Professor Jaephil Cho (left) and his research team in the School of Energy and Chemical Engineering
at the Ulsan National Institute of Science and Technology (UNIST), South Korea. 2018 (Photo courtesy UNIST)




The new aluminum-air flow battery developed in a university lab in South Korea is more energy-efficient than gasoline-powered engines and less fire-prone than the lithium-ion batteries in wide use today.



This new type of battery for EVs outperforms lithium-ion batteries in terms of higher energy density, lower cost, longer cycle life, and higher safety capability.



This breakthrough is led by Professor Jaephil Cho and his research team in the School of Energy and Chemical Engineering at the Ulsan National Institute of Science and Technology, one of the four public universities in South Korea dedicated to research in science and technology.



The findings were published in the journal "Nature Communications" on September 13, 2018.



Aluminium–air batteries are primary cells, which means that they are non-rechargeable in the usual manner.



Once the aluminium anode is consumed by its reaction with atmospheric oxygen at a cathode immersed in a water-based electrolyte to form hydrated aluminium oxide, the battery will no longer produce electricity.



Drivers who need more juice can just switch their used aluminum-air flow battery packs for fresh ones, a time-saving convenience.



The new aluminum-air flow battery provides a lightweight, high-energy density power source with little risk of catching fire or explosion the way lithium-ion batteries are known to do.



Professor Cho said, "With 1kg of aluminum, we can build a battery that enables an electric car to run up to 700km."



The new battery works much like metal-air batteries, as it produces electricity from the reaction of oxygen in the air with aluminium.



Metal-air batteries, especially aluminium-air batteries, have attracted much attention as the next-generation battery due to their energy density, which is higher than that of lithium-ion batteries.



Indeed, batteries that use aluminum, a lightweight metal, are lighter, cheaper, and have a greater capacity than lithium-ion batteries.



While aluminum-air batteries are one of the highest energy densities of all batteries, they are not widely used because of problems with high anode cost and byproduct removal when using traditional electrolytes.



Professor Cho says he has solved this issue by developing a flow-based aluminum-air battery to alleviate the side reactions in the cell, where the electrolytes can be continuously circulated.



Thanks to improved logevity and energy density, the team anticipates that their aluminum-air flow battery system could help bring more EVs on the road with greater range and substantially less weight with zero risk of explosion.



Jaechan Ryu, first author of the study, says the team believes their aluminum-air flow battery system has the potential for "a cost-effective and safe next-generation energy conversion system."



Jaechan Ryu et al., "Seed-mediated atomic-scale reconstruction of silver manganate nanoplates for oxygen reduction towards high-energy aluminum-air flow batteries," Nature Communications, (2018).



By Sunny Lewis

Environment News Service (ENS)

October 15, 2018