The growth in the number of electric vehicles and energy storage systems relies on lithium-ion batteries. However, their production leaves a noticeable carbon footprint. Researchers from the University of Melbourne, together with colleagues from the Chinese Academy of Sciences and the University of Sheffield, have worked out how to keep this footprint under control. The work was published in the journal One Earth.
The scientists built a model of the entire supply chain - from raw material extraction to battery production and their recycling - for the period from 2024 to 2050. The calculations showed that if nothing changes, demand for batteries for transport and stationary energy storage systems will grow by about 20 times, and greenhouse gas emissions in the supply chain by ten times.
The authors emphasize that "greening" production alone - cleaner battery chemistries, renewable energy at factories and recovery of materials from old batteries - does not solve the problem. These measures are necessary, but they do not offset the coming growth.
An additional reserve is reducing demand itself. This concerns four factors: smaller battery sizes, longer service life, reuse after their resource is exhausted, and the development of shared transport use. The model showed that all of them together significantly reduce the number of new batteries the world will need.
If ambitious measures are combined both in production and on the consumption side, total emissions from the global battery supply chain by 2050 will amount to about 9-12 billion tonnes of CO2-equivalent (carbon dioxide equivalent - a single measure for different greenhouse gases). Without these measures, the figure would reach 19-23 billion tonnes. Thus, emissions can be cut by about half. Of this reduction, about 3.5-4.7 billion tonnes come from production measures, and around 6-7 billion tonnes from lower demand. According to the authors, this is comparable to the annual emissions of an entire large economy, for example the European Union.
Lead author Haiwei Zhou notes that the team wants to improve the model's accuracy by region in the future, since the conditions for extraction, processing and electricity supply vary greatly. In addition, the scientists plan to check whether the same logic of "production versus demand" works in other fast-growing clean energy technologies - wind turbines and solar panels.
The researchers emphasize that battery policy should not be limited to regulating emissions at factories only. It can encourage longer battery service life, adequate size and reuse. The main question, according to the authors, is not only "what is the carbon footprint of each battery?" but also "how much capacity do we really need to get the same service?".
The work is based on modeling and is not proof that the listed measures already work in practice. However, it shows which combinations of solutions can produce the greatest effect.