Can electric cars kick the cobalt habit?
The mineral is a key component of batteries used in electric vehicles, but we may run out within a decade. It would be better to stop using it altogether, says Donna Lu
ELECTRIC cars are getting cheaper and their sales are on the rise, but their future success may depend on ditching a key ingredient: the heavy metal cobalt.
The mineral is used in the lithium-ion batteries that power most electric cars, and demand for it is steadily increasing. A new analysis by Elsa Olivetti at the Massachusetts Institute of Technology and her colleagues has found that there may be cobalt shortages if we don’t start refining and recycling it more efficiently or in greater quantities.
They estimate that global demand for cobalt will rise to between 235,000 and 430,000 tonnes by 2030– an amount that is at least 1.6 times the world’s current capacity to refine the metal, as of 2016 figures (Environmental Science& Technology, doi.org/dm6b).
About half of all cobalt goes to make lithium-ion batteries for electric cars and other consumer electronics. Demand for these batteries is projected to more than quadruple over the next decade.
Cobalt is often produced as a by-product of copper or nickel mining. It is expensive, at around $33,000 per tonne, and also comes with a human cost. Most of the world’s supply –60 per cent – comes from the Democratic Republic of the Congo, where mining has been linked to child labour and deaths.
The new analysis suggests short-term cobalt supply is adequate, but that more mining exploration, such as in the ocean is required. In addition, we will need to ramp up cobalt recycling by recovering it from batteries in redundant electric cars, laptops and mobile phones.
Another option is to shift to batteries that use less cobalt, or none at all. Elon Musk’s car firm Tesla is in talks with battery manufacturer CATL to use entirely cobalt-free batteries in its China-made cars, according to a report last week by Reuters.
Lithium-ion batteries in electric cars commonly use either lithium nickel cobalt aluminium oxide or lithium nickel manganese cobalt oxide for their ability to provide a long lifespan and high energy density – a key factor in how far an electric car can go on a single charge.
For short-range cars made and sold in China, Reuters says Tesla will instead use lithium iron phosphate batteries, which are much cheaper and have less of an environmental impact compared with those needing cobalt. The disadvantage is that they tend to have a lower energy density, reducing how far a car can travel without needing to be charged.
Industry analysts such as Simon Moores at Benchmark Mineral Intelligence in London have suggested that the move is unlikely to be replicated outside China, saying it is driven more by a desire to reduce production costs in China than to phase out cobalt.
Lithium iron phosphate batteries are already widely used by other Chinese firms, including BYD, the world’s biggest electric car manufacturer. If other electric car manufacturers follow internationally, we may be able to reduce our dependence on a dwindling mineral resource.
The New Scientist, 29 February 2020, p.15