Last year was an exciting one for electric vehicles (EVs). General Motors, Renault-Nissan and Tesla unveiled new models at the Paris motor show in October; Jaguar paraded an electric SUV in Los Angeles in November.

The fact that EVs are now expected to make up a growing proportion of vehicles sold by the 2020s could be good news for cutting carbon emissions. But how the batteries that power them are manufactured is a cause of concern to campaigners, who fear that this surge in demand will fuel conflict and aggravate poor conditions for workers in unstable Majority World countries where the rare minerals that go into the lithiumion batteries are mined.

One such vital material is cobalt. Some 60 per cent of global supply is sourced from the Democratic Republic of Congo (DRC), which is suffering a surge in pollution and birth defects as a result of cobalt mining, according to a recent investigation by The Washington Post.

‘It is a major paradox of the digital era that some of the world’s richest, most innovative companies are able to market incredibly sophisticated devices without being required to show where they source raw materials for their components,’ says Emmanuel Umpula, Director of Afrewatch, a DRC-based NGO that works towards the just and sustainable use of natural resources.

Worldwide, cobalt demand from the battery sector has tripled in the past five years and is projected to at least double again by 2020. Demand is increasingly driven by the EV market; a smartphone battery might contain five to ten grams of refined cobalt, while an EV’s can contain up to 15,000 grams.

‘Cobalt supply is tightening, with the world’s primary producer – the DRC – suffering from crumbling infrastructure and massive human rights challenges,’ warns Harrison Mitchell, Director of RCS Global, which advises on and audits mineral supply chains.

A joint report by Afrewatch and Amnesty International recently found that cobalt supplied to EV manufacturers through various intermediaries was at risk of containing supplies from DRC mines that use child labour. Cobalt is not currently listed as a conflict mineral under US and OECD guidelines which require companies to identify the source of minerals in their products. NGOs are pushing for this to change.

‘The abuses in mines remain out of sight and out of mind,’ says Umpula. ‘We found that traders are buying cobalt without asking questions about how and where it was mined.’

Neil Thompson