Electric vehicles are the future of transport. Electric vehicle sales increase year after year and, in 2019, accounted for 2.6 percent of global car sales. Electric vehicles are an essential change to be made for reducing the number of greenhouse gases and non-renewable resources used by humans, and these vehicles need batteries, which still need special materials. How do manufacturers acquire those materials in a sustainable way?

Extracting lithium from water

Electric batteries are composed of the key element lithium, but with the growing demand for these batteries, the world faces a problem. Researchers at the Pacific Northwest National Laboratory have come up with an innovative solution to this, creating a method to extract lithium and other minerals from wastewater.

The technique works by utilizing magnetic nanoparticles and magnetic fields to bind to specific materials in the water, which are then extracted. “We believe that this thing can be big,” said Jian Liu, a senior research engineer at the lab.

Wastewater left over from industry and brine from geothermal power (renewable energy from heat within the Earth) systems are sources that could be used in this method. Using these sources means the partial cleanup of environmentally harmful waste products.

The U.S. has over 100 geothermal power plants, most of which are small. Entrepreneurs are currently looking to expand their presence to make geothermal energy a larger part of the energy mix and importantly move the country closer to a greener energy system. With the expansion of these plants comes new opportunities for lithium sources.

Is this extraction method beneficial?

The lab predicts that around one trillion gallons of wastewater are produced annually by the U.S. With an average of nine parts per million lithium in this water, 34,000 tons of lithium per year could potentially be recovered. This number is several times higher than the amount the country is currently producing.

This approach to lithium production has the potential for the U.S. to produce more lithium to meet electric battery demand and for the element to be extracted in an eco-friendlier manner. The only downside is the current cost to extract lithium from wastewater when there is a low concentration of the element, however, the team is continuing to look for ways to optimize the process, making it cheaper and extracting more lithium.