Recycling Lithium Batteries With Vitamin C
While advances in battery technology have focused on charging and performance, the issue of recycling efficacy has received less research attention. A method using ascorbic acid effectively preserves high-value battery material by efficiently separating it from low-value material.
The electric vehicle (EV) market is growing quickly, and as it expands, so does the hope that a major shift toward green transportation technology will reduce carbon footprints across the globe. But to successfully usher in this clean transportation revolution, engineers are still searching for better methods to recycle the millions of batteries needed for this market. A U.K. research team has pioneered a technique that focuses on the battery cathode, using ascorbic acid as a leaching agent to preserve high-value material from the cathode, including the nickel and cobalt components.
Used lithium-ion battery in the process of being recycled. Image used courtesy of Science
Lithium mining and battery recycling both present environmental challenges, and to maximize this technology, engineers have been stepping in to advance battery recycling methods, which can be expensive and create hazardous waste.
Lithium-ion batteries (Li-ions) have several components. Recycling techniques typically focus on the battery cathode, which contains the most high-value material that can be successfully reused— but only if there is a recycling method that can preserve its value.
The Costs and Challenges of Li-ion Recycling
Li-ions have an impressive life cycle compared to batteries that operate in combustion engines. They can last 10-15 years, depending on climate and charging patterns, while the life cycle of batteries used in combustion engine cars is typically three to five years.
Even though this improvement in longevity is noteworthy, Li-ions will still need to be dealt with from a waste and recycling perspective. And with the rapid growth of the EV market, there is a risk of creating a massive amount of hazardous waste from discarded Li-ions. Over 10 million EVs were sold in 2022, and current market projections estimate a 35% annual growth rate.
As EV sales increase, so does the use of lithium-ion batteries. Image used courtesy of NREL
With those millions of EVs will come many more batteries needing to be recycled. But the two common methods for battery recycling, pyrometallurgy and hydrometallurgy, capture little of the high-value material in the batteries.
Pyrometallurgy involves high-temperature furnaces that burn much of the battery components off so that small amounts of nickel and cobalt can be recovered. Hydrometallurgy, conversely, uses chemical processes to reclaim metals from the batteries after a labor-intensive process of mechanically shredding them.
Both the high labor and costs of these processes, as well as the limitations of how much high-value battery material is recovered, make them less than ideal. In addition to such limitations, recycling infrastructure is not equipped to reclaim lithium, so the current recycling centers lack the tools to handle the upcoming influx of discarded Li-ions.
Using Ascorbic Acid to Preserve Cathode Materials
Three researchers from the University of Birmingham's School of Chemistry have invented a leaching technique that can preserve a significant amount of high-value material from the cathodes of Li-ions.
They have found that ascorbic acid (vitamin C) can successfully leach low-value material out of the cathodes, leaving high-value material intact and ready for direct recycling. Their research was performed on an actual end-of-life EV battery, while many studies use modeling techniques, and their results show that this leaching process can be completed in a matter of minutes.
The efficiency of the process, as well as its capacity to avoid contaminating the nickel-rich layered oxide from the retired battery, make this a promising battery recycling innovation that can reduce Li-ion waste and bypass other costly recycling methods that do not recover significant amounts of high-value material.
The High-Value Impact of Improved Li-ion Recycling
This recycling technique can improve both safety and cost savings. Li-ions not recycled can start fires when discarded in waste management facilities. Widespread disposal is not only risky from a safety angle but also costly, not to mention hazardous to the environment. But with the right advances in recycling techniques, Li-ion recycling can turn into a financial gold mine that simultaneously protects the environment.
Recycling lithium-ion batteries preserves natural resources. Image used courtesy of EPA
The EV battery recycling market was worth 2.3 billion dollars in 2022, and experts estimate that it will keep growing significantly at an annual rate of 27.3%.
This innovative ascorbic acid leaching technique can optimize Li-ion recycling and transform it from a cumbersome liability of the EV market to an exciting value proposition that can reduce costs and negative environmental impacts at the same time.