One of the recurring criticisms of electric vehicles is the carbon footprint of battery manufacturing, which represents a significant increment compared to the vehicle itself.
Indeed, to achieve a positive carbon balance using an electric vehicle (EV), one must travel a certain distance (between 20 to 45,000 kilometers according to various studies – Ademe/Carbone4/TU Eindhoven/IFEU -) with fairly decarbonized electricity to offset this manufacturing increment.
Therefore, the battery is the elephant in the room regarding the environmental virtue of electric vehicles, prompting the question of whether there are solutions to address this challenge.
Looking at the details, most simulations assume batteries are manufactured in the USA or China, using NMC technology with highly carbon-intensive electricity, resulting in an average carbon footprint of 108 kg CO2e/kWh (McKinsey estimation). For a “standard” 60 kWh battery, this would result in a manufacturing carbon footprint of 6.5 tonnes of CO2e.
This analysis is subject to challenge by efforts made by governments and the technical and scientific community.
New high-density technologies inherently require significantly less material mass to store one kilowatt-hour. This is a primary factor in reducing mass and consequently, the carbon footprint.
Some countries (Switzerland, Norway, Sweden, France, etc.) have much more decarbonized electricity (20, 30, 40, 60 gCO2e/kWh respectively) compared to the reference values used in calculations (US 387 gCO2e/kWh, China 530 gCO2e/kWh).
Not all technologies consume the same energy during manufacturing. For instance, producing 1 kWh of LFP battery consumes approximately 37 kWh of electricity, whereas NMC consumes 26 kWh, and solid-state batteries require 3.5 kWh (source: Nature Energies).
Different technologies use different materials, resulting in varying upstream carbon footprints (from production and refining). Batteries with graphite or silicon anodes and lithium-iron-phosphate cathodes are particularly emissive. Solid-state or sodium batteries are particularly interesting for drastically reducing these emissions. Moreover, recent initiatives for new mines in low-carbon countries suggest carbon emissions from ore production could be significantly lower than in the USA or China.
Considering ongoing industrial initiatives, by combining the right technologies, considerably increased power densities, sourcing minerals from low-carbon countries, and manufacturing batteries in low-carbon countries, it’s likely that we can halve the carbon footprint of currently assessed batteries. A target of 50 kg CO2e/kWh is not unrealistic.
This would reduce the carbon footprint of a 60 kWh battery to 3 tonnes of CO2e, bringing carbon neutrality in usage closer to around 10,000 kilometers.
Therefore, it’s crucial to work on and make the right industrial and energy choices.