IVL The Swedish Environment Institute has, on behalf of the Swedish Transport Administration and the Swedish Energy Agency, investigated the climate impact of lithium-ion batteries from a life-cycle perspective. There are batteries for electric cars that are included in the study. The two authors Lisbeth Dahllöf and Mia Romare have done a metastudy, that is, reviewed and compiled existing studies.
The report shows that battery manufacturing leads to high emissions. For each kilowatt-hour storage capacity in the battery, emissions of 150 to 200 kilograms of carbon dioxide equivalent are generated, already in the factory. The researchers have not studied the individual car brand batteries, just how they were produced or what electrical mix they used. But if we understand the importance of battery size, one example: Two standard electric cars on the market, Nissan Leaf and Tesla Model S, have batteries of approximately 30 kWh and 100 kWh respectively.
As soon as you buy the car, emissions have thus come about approximately 5.3 tonnes and 17.5 tonnes, for batteries of these sizes. The numbers can be difficult to relate to. By way of comparison, a trip for a person returning from Stockholm to New York by air causes emissions of more than 600 kilograms of carbon dioxide, according to the UN organization ICAO's calculation model.
Another conclusion in the study is that about half of the emissions occur in the production of raw material and half in the production of the battery itself in the factory. The mining itself accounts for only a small part of between 10-20 percent.
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The calculation is based on the assumption that the electricity mix used in the battery plant accounts for more than half of fossil power. In Sweden, power generation predominantly consists of fossil-free nuclear and hydropower, as a result of which lower emissions could have been achieved.
The study also results in emissions rising almost linearly with the battery size, even though data in that area is scarcer. This means that a Tesla-size battery contributes more than three times as much as Nissan Leaf's size. It is a result that surprised Mia Romare.
"It should have been less linear because the electronics used do not increase to the same extent. But the battery cells themselves are as influential as the production looks today, she says.
"One conclusion is that you should not drive unnecessarily large batteries," says Mia Romare
The authors emphasize that a large part of the study has been about finding out what data is available and finding out what quality they hold. In many cases they have been forced to find that it is difficult to compare existing studies with each other.
"We have been frustrated, but it is also part of the result," says Lisbeth Dahllöf.
The colleague Mats-Ola Larsson at IVL has calculated how long you need to drive a gasoline or diesel car before it has released as much carbon dioxide as battery manufacturing has caused. The result was 2.7 years for a battery of the same size as Nissan Leaf and 8.2 years for a battery of Tesla size, based on a series of assumptions (see the fact box below).
"It's great for companies and government to embark on ambitious environmental policies and to buy climate-smart cars. But these results show that one should not think of choosing an electric car with a larger battery than necessary, he says, and points out that politicians should also address this in the design of instruments.
An obvious part of life cycle analysis is recycling. The report authors note that what characterizes batteries is the lack of the same as there is no financial incentive to send the batteries for recycling and that the volumes are still small.
Cobalt, nickel and copper are recycled but not the energy required to manufacture the electrodes, says Mia Romare, pointing out that recycling is a resource-saving point rather than a reduction of carbon dioxide emissions.
Peter Kasche from the report publisher The Energy Agency highlights the close relationship between the battery size and emissions as important.
- In some way, one must really make sure that you optimize the batteries. You should not drive around with a lot of kilowatt hours unnecessarily. In some cases, a plug in-hybrid may be the optimum, in other cases a clean battery device.

Then counted IVL

Mats-Ola Larsson has made a number of assumptions when calculating that the emissions from a Nissan Leaf size battery and a Tesla size battery take 2.7 and 8.2 years to "run together" with a regular petrol or diesel car:
The average emission of new Swedish cars in 2016 was 126 grams of carbon dioxide per kilometer. That value has been corrected to 130 because some of the cars classified as electric cars are charge hybrids, which sometimes run on fossil fuels.
At the same time, gasoline and diesel are assumed to have 18 percent renewable fuels, which affect emissions.
The average mileage per year is 1 224 miles according to Traffic Analysis.