In the quest for greater mileage per charge, electric car batteries are getting much bigger. But since battery production is energy consuming and to some extent cancels out climate benefit, it is vital that production becomes more energy efficient and that the use of fossil electricity is minimized, reveals a report that IVL Swedish Environmental Research Institute has carried out, on behalf of the Swedish Energy Agency and the Swedish Transport Administration.

“It’s important to assess the whole picture and to minimize environmental impact in the production stage”, says Lisbeth Dahllöf, researcher at IVL Swedish Environmental Research Institute. Together, with colleague her Mia Romare, she has reviewed the literature on greenhouse gas emissions and energy consumption during the production and recycling of lithium-ion automotive batteries for light vehicles.

According to the authors of the report, the production of lithium-ion batteries for light electric vehicles releases on average 150-200 kilos of carbon dioxide equivalents per kilowatt-hour battery. One of the smallest electric cars on the market, Nissan Leaf, uses batteries of approx. 30 kWh, but many new models have batteries of 60 and 100 kWh. The study finds an electric car with a 100kWh battery has thus emitted 15-20 tons of carbon dioxide even before the vehicle ignition is turned on. This calculation assumes a 50-70 per cent fossil share in the electricity mix.

“For a sustainable future, it is important that the production of electric car batteries is as energy-efficient as possible and made with electricity that is either completely without, or with a very low, carbon emission”, says Mia Romare.