Scientists finds faster, cleaner way to extract lithium from battery waste

The “white gold” of fresh power, lithium is a key ingredient in batteries giant and small, from these powering telephones and laptops to grid-scale power storage methods.

Although comparatively considerable, the silvery-white metallic might quickly be briefly provide resulting from a posh sourcing panorama impacted by the electrical automobile (EV) growth, net-zero targets and geopolitical components. Valued at over $65 billion in 2023, the lithium-ion battery (LIB) global market is predicted to develop by over 23% within the subsequent eight years, doubtless heightening present challenges in lithium provide.

What’s extra, recovering lithium from spent batteries is environmentally taxing and extremely inefficient ⎯ one thing a workforce of Rice College researchers led by Pulickel Ajayan is working to vary.

Of their latest study printed in Superior Practical Suppliesthe researchers describe a fast, environment friendly and environmentally pleasant methodology for selective lithium restoration utilizing microwave radiation and a readily biodegradable solvent. Findings present the brand new course of can retrieve as a lot as 50% of the lithium in spent LIB cathodes in as little as 30 seconds, overcoming a major bottleneck in LIB recycling expertise.

“We’ve seen a colossal growth in LIB use in recent years, which inevitably raises concerns as to the availability of critical metals like lithium, cobalt and nickel that are used in the cathodes,” stated Sohini Bhattacharyya, one of many two lead authors on the examine and a Rice Academy Postdoctoral Fellow within the Nanomaterials Laboratory run by Ajayan. “It’s therefore really important to recycle spent LIBs to recover these metals.”

Typical recycling strategies typically contain harsh acids, whereas different eco-friendly solvents like deep eutectic solvents (DESs) have struggled with effectivity and financial viability. Furthermore, present recycling strategies recuperate lower than 5% of lithium, largely resulting from contamination and loss through the course of in addition to the power intensive nature of restoration.

“The recovery rate is so low because lithium is usually precipitated last after all other metals, so our goal was to figure out how we can target lithium specifically,” stated Salma Alhashim, a Rice doctoral alumna who’s the examine’s different lead creator.

“Here we used a DES that is a mixture of choline chloride and ethylene glycol, knowing from our previous work that during leaching in this DES, lithium gets surrounded by chloride ions from the choline chloride and is leached out into solution.”

In an effort to leach different metals like cobalt or nickel, each the choline chloride and the ethylene glycol need to be concerned within the course of. Figuring out that of the 2 substances solely choline chloride is nice at absorbing microwaves, the researchers submerged the battery waste materials within the solvent and blasted it with microwave radiation.

“This allowed us to leach lithium selectively over other metals,” Bhattacharyya stated. “Using microwave radiation for this process is akin to how a kitchen microwave heats food quickly. The energy is transferred directly to the molecules, making the reaction occur much faster than conventional heating methods.”

In comparison with typical heating strategies like an oil tub, microwave-assisted heating can obtain related efficiencies virtually 100 occasions quicker. For instance, utilizing the microwave-based course of, the workforce discovered that it took quarter-hour to leach 87% of the lithium versus the 12 hours wanted to acquire the identical restoration charge through oil tub heating.

“This also shows that selectivity towards specific elements can be achieved simply by tuning the DES composition,” Alhashim stated. “Another advantage is solvent stability: Because the oil bath method takes so much longer, the solvent begins to decompose, whereas this does not happen with the short heating cycles of a microwave.”

This breakthrough methodology might dramatically enhance the financial and environmental impact of LIB recycling, offering a sustainable resolution to a rising international difficulty.

“This method not only enhances the recovery rate but also minimizes environmental impact, which makes it a promising step toward deploying DES-based recycling systems at scale for selective metal recovery,” stated Ajayan, the corresponding creator on the examine and Rice’s Benjamin M. and Mary Greenwood Anderson Professor of Engineering and professor and division chair of supplies science and nanoengineering.