The dirty secret under the hoods of electric cars no one talks about

Yet regulators haven't set out clear guidelines on acceptable carbon emissions over the life cycle of electric cars

Beneath the hoods of millions of the clean electric cars rolling onto the world’s roads in the next few years will be a dirty battery.

Every major carmaker has plans for electric vehicles to cut greenhouse gas emissions, yet their manufacturers are, by and large, making lithium-ion batteries in places with some of the most polluting grids in the world.

By 2021, capacity will exist to build batteries for more than 10 million cars running on 60 kilowatt-hour packs, according to data of Bloomberg NEF. Most supply will come from places like China, Thailand, Germany and Poland that rely on