KAERI develops eco-friendly method for recycling EV batteries

A researcher at the Korea Atomic Energy Research Institute in Daejeon collects black powder from wasted EV batteries after mixing it with chlorine gas. Courtesy of Korea Atomic Energy Research Institute

The Korea Atomic Energy Research Institute (KAERI) has developed a new way to recycle used batteries from electric vehicles (EV) which it says salvages more critical components and is environmentally safer than prior methods.

The Daejeon-headquartered research institute said Wednesday its new upcycling technology recovers almost 97 percent of lithium from wasted EV batteries. Anode materials ― which account for more than 40 percent of EV battery manufacturing costs ― that are generated by the new method also demonstrated an extended lifespan by 30 percent. The method also generated less pollution than the conventional way of recycling batteries, the institute added.

To recycle EV batteries, their anodes are separately collected and pulverized into black powder. Prior methods either melted the powder with chemical solutions or heated it to 900 degrees Celsius. Both treatments are used to sort out residual metallic elements like lithium, nickel and cobalt.

KAERI rejected the melting method, which generates highly toxic wastewater, and chose to develop the heating method further. Researchers mixed the black power with chlorine gas to separately extract lithium chloride and black power residue. They said lithium chloride is water-soluble and easy to salvage pure lithium from it.

The researchers then added the lithium-free black powder to lithium and nickel to create upcycled anode materials. The anodes formed using this method have been discovered to have a longer lifespan than those in original batteries.

EV batteries use lithium-ion batteries and consist of anodes, cathodes, electrolytes and current collectors. Anodes contain lithium, nickel and cobalt, and the amount of these elements that is salvaged can determine the quality of recycled batteries.

"The quality of EV batteries is determined by how much lithium anodes contain," said Kim Hyeong-sub, one of the three KAERI researchers who developed the recycling method. "Conventional methods used so far have amalgamated residual lithium following the heating treatment with other metallic components in ways that lowered battery quality and destabilized anodes."

Kim said his team will continue developing the method and transfer the technologies to firms in Korea. He added the new method will become a guideline for recycling wasted EV batteries in an eco-friendly way.