Researchers look at metals bottlenecks for batteries

October 12, 2017 // By Nick Flaherty
US researchers have looked at the global available of the most common metals used in battery production, particularly lithium and cobalt, to see if there are restrictions to volume production.

The dramatic rise in production of electric vehicles, coupled with expected growth in the use of grid-connected battery systems for storing electricity from renewable sources, has raised the question of whether there are enough raw materials to enable significantly increased production of lithium-ion batteries.

The analysis sees no immediate limitations on battery manufacturing due to shortages of the critical metals they require but highlights short-term bottlenecks in the supplies of some metals, particularly lithium and cobalt, that could cause temporary slowdowns in production.

The analysis by professor Elsa Olivetti and doctoral student Xinkai Fu in the Department of Materials Science and Engineering at the Massachusetts Institute of Technology, Gerbrand Ceder at the University of California at Berkeley, and Gabrielle Gaustad at the Rochester Institute of Technology concentrated on five of the most essential ingredients needed to produce today's lithium-ion batteries: lithium, cobalt, manganese, nickel, and carbon in the form of graphite. Other key ingredients, such as copper, aluminum, and some polymers used as membranes, are considered abundant enough that they are not likely to be a limiting factor.

Among those five materials, it was quickly clear that nickel and manganese are used much more widely in other industries; battery production, even if significantly increased, is "not a significant part of the pie," says Olivetti, so nickel and manganese supplies are not likely to be impacted. Ultimately, the most significant materials whose supply chains could become limited are lithium and cobalt.

For those two elements, the team looked at the diversity of the supply options in terms of geographical distribution, production facilities, and other variables. For lithium, there are two main pathways to production: mining and processing of brines. Of those, production from brine can be ramped up to meet demand much more rapidly, within as little as six or eight months, compared to bringing a new underground mine into production. Although there might still be disruptions in the supply of lithium, she says, these are unlikely to seriously disrupt battery production.

Cobalt is a bit more complex. The main source is the Democratic Republic of the Congo, which has a history of violent conflict and corruption. "That's been a challenge," said Olivetti. Cobalt is typically produced as a byproduct of other mining activity. "Often a mine's revenue comes from nickel, and cobalt is a secondary product," she says.

But the main potential cause of delays in obtaining new supplies of the mineral comes from not its inherent geographic distribution, but the actual extraction infrastructure. "The delay is in the ability to open new mines," she says. "With any of these things, the material is out there, but the question is at what price." To guard against possible disruptions in the cobalt supply, she says, researchers "are trying to move to cathode materials [for lithium-ion batteries] that are less cobalt-dependent."

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