According to a study published in Advanced Energy Materials, a research team at the Korea Institute of Energy Research’s Gwangju Clean Energy Research Center, under Dr. Jung-Je Woo, has successfully created an economical and environmentally responsible method for recycling cathode materials from spent lithium-ion batteries.
Spent cathode material immersed in restorative solution. Image Credit: Korea Institute of Energy Research
Managing spent batteries has emerged as a major worldwide concern following the recent increase in electric cars and mobile devices. ItI is anticipated that over 40 million discarded electric vehicles will be in use by 2040, resulting in a significant rise in waste batteries.
As battery metals present a serious risk of contaminating soil and water, developing cutting-edge recycling methods has become a top concern.
Conventional battery recycling usually entails crushing spent batteries and using chemical procedures to extract important metals like cobalt, nickel, and lithium.
This process necessitates high-concentration chemicals, which produce wastewater and use a lot of energy as high-temperature furnaces are required and contribute significantly to carbon dioxide emissions.
Direct recycling technology has been gaining popularity as a solution to these problems. It recovers and restores original materials without undergoing chemical change.
Direct recycling also has disadvantages. It involves complicated processes and necessitates high temperatures and pressures, which makes it expensive and time-consuming.
To overcome the drawbacks of traditional recycling techniques, the research team has created a revolutionary technology that allows spent cathode materials from lithium-ion batteries to be recycled directly through a straightforward procedure.
This novel method efficiently replenishes lithium ions and returns the cathode to its initial state by submerging the spent cathode in a restoration solution at room temperature and pressure.
The application of galvanic corrosion utilizing a restoration solution is the primary technology.
Galvanic corrosion occurs when two dissimilar materials come into contact under an electrolyte environment, causing one metal to selectively corrode to shield the other. The study team has modified this phenomenon for battery recycling through this sacrificial technique.
Spontaneous corrosion begins when the metal in the spent battery comes into contact with the bromine in the repair solution. During this process, electrons are released from the corroded aluminum and moved to the spent cathode material.
Lithium ions from the restoration solution are introduced into the cathode material to preserve charge neutrality. This lithium-ion recovery causes the cathode material to return to its initial state.
The restoration reaction occurs directly within the cell, significantly improving the recycling process’s efficiency compared to traditional techniques that call for disassembling the spent battery.
Through electrochemical performance testing, the study team confirmed that the repaired cathode had the same capacity as the new materials.
This research introduces a novel approach to restoring spent cathode materials without the need for high-temperature heat treatment or harmful chemicals. The direct recycling of discarded electric vehicle batteries holds great potential for significantly reducing carbon emissions and establishing a circular resource economy.
Dr. Jung-Je Woo, Senior Researcher, Gwangju Clean Energy Research Center, Korea Institute of Energy Research
Journal Reference:
Song, J. et. al. (2024) Reviving Spent NCM Cathodes via Spontaneous Galvanic Corrosion in Ambient Atmospheric Condition. Advanced Energy Materials. doi.org/10.1002/aenm.202402106