Digging Deep in the Sea: "It is imperative to fully understand the environmental impact of mining resources from the deep ocean and compare it to the environmental impact of mining resources on land.".

• Author: Gallagher, Mary Beth
• Position: Science & Technology - Interview

RESTING ATOP Thomas Peacock's desk is an ordinary-looking brown rock. Roughly the size of a potato, it has been at the center of decades of debate. Known as a polymetallic nodule, it spent 10,000,000 years sitting on the deep seabed, 15,000 feet below sea level. The nodule contains nickel, cobalt, copper, and manganese--four minerals that are essential in energy storage.

"As society moves toward driving more electric vehicles and utilizing renewable energy, there will be an increased demand for these minerals to manufacture the batteries necessary to decarbonize the economy," says Peacock, professor of mechanical engineering and director of the Massachusetts Institute of Technology's Environmental Dynamics Lab (END Lab). He is part of an international team of researchers that has been trying to gain a better understanding the environmental impact of collecting polymetallic nodules, a process known as deep-sea mining.

The minerals found in the nodules, particularly cobalt and nickel, are key components of lithium-ion batteries, which offer the best energy density of any commercially available battery. This high-energy density makes them ideal for use in everything from cell phones to electric vehicles, which require large amounts of energy within a compact space. "Those two elements are expected to see a tremendous growth in demand due to energy storage," says Richard Roth, director of MIT's Materials Systems Laboratory.

While researchers are exploring alternative battery technologies such as sodium-ion and flow batteries that utilize electrochemical cells, these technologies are far from commercialization. "Few people expect any of these lithium-ion alternatives to be available in the next decade," explains Roth. "Waiting for unknown future battery chemistries and technologies could significantly delay widespread adoption of electric vehicles."

Vast amounts of specialty nickel also will be needed to build larger-scale batteries that will be required as societies look to shift from an electric grid powered by fossil fuels to one powered by renewable resources like solar, wind, wave, and thermal. "The collection of nodules from the seabed is being considered as a new means for getting these materials but, before doing so, it is imperative to fully understand the environmental impact of mining resources from the deep ocean and compare it to the environmental impact of mining resources on land," says Peacock.

After receiving seed funding from...