The drive to replace polluting petrol and diesel cars with a new breed of electric vehicles has gathered momentum in recent weeks. But there is an unanswered environmental question at the heart of the electric car movement: what on earth to do with their half-tonne lithium-ion batteries when they wear out?
British and French governments last month committed to outlaw the sale of petrol- and diesel-powered cars by 2040, and carmaker Volvo pledged to only sell electric or hybrid vehicles from 2019.
The number of electric cars in the world passed the 2m mark last year and the International Energy Agency estimates there will be 140m electric cars globally by 2030 if countries meet Paris climate agreement targets. This electric vehicle boom could leave 11m tonnes of spent lithium-ion batteries in need of recycling between now and 2030, according to Ajay Kochhar, CEO of Canadian battery recycling startup Li-Cycle.
However, in the EU as few as 5% (pdf) of lithium-ion batteries are recycled. This has an environmental cost. Not only do the batteries carry a risk of giving off toxic gases if damaged, but core ingredients such as lithium and cobalt are finite and extraction can lead to water pollution and depletion among other environmental consequences.