Sustainable battery raw material that grows in the forest
The mobility transition stands and falls with battery technology for electric cars. Graphite is an essential raw material for this. However, this raw material is rare and its extraction has a significant environmental footprint. Battery manufacturers are looking for more sustainable materials for e-mobility solutions in order to reduceCO2 emissions. One such alternative is the use of biobased hard carbon based on wood.
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Lithium-ion batteries are currently the most common and at the same time very resource-intensive drive standard in electric vehicles. This is mainly due to the raw materials required for production. The cathode alone of a battery for a standard mid-range car contains several kilograms of manganese, lithium, cobalt and nickel.
Graphite is also required for the anode, and more than the other raw materials, namely 50 to 100 kg per EV battery. Graphite is therefore the largest component, accounting for up to 50% of the weight of a lithium-ion battery.
"Currently, the data shows a looming mismatch between the world's increased climate change ambitions and the availability of key minerals essential to their realization," says the Director of the International Energy Agency (IEA).
Around 96 percent of the anodes in lithium-ion batteries contain graphite as their main component. This can be mined as natural graphite or produced synthetically. Both materials - natural and synthetic graphite - today come largely from China, which controls over 75 percent of the current market and also processes more than 90 percent of the graphite. They have a significant environmental footprint. Graphite is not very productive and the market is highly competitive. China's dominant market position is increasingly leading to export restrictions as well as considerable supply risks and price fluctuations.
Synthetic production
The production of synthetic graphite requires a carbon source that is usually a by-product of the oil and coal industry. This requires very high temperatures of more than 2,500 degrees Celsius over several days, which is only possible in special electric furnaces. The associated emissions depend very much on the energy mix used.
US and European companies are currently investing in the development of synthetic graphite, which Benchmark Mineral Intelligence estimates could account for almost two-thirds of the EV battery anode market by 2025.
Graphite extraction through carbon capture and utilization, also known as carbon capture and utilization (CCU)
Graphite is not extracted as a primary raw material through mining, which is known to lead to the release of considerable amounts ofCO2, but is obtained from the capture ofCO2. With this technology, 3.7 tons ofCO2 are captured directly from the atmosphere or from industrial emissions for every ton of graphite or carbon nanomaterials produced.
Bio-based graphite from the waste product lignin
Battery manufacturer Northvolt, which laid the foundation stone for its third large battery factory in Germany at the beginning of the year, has entered into a development partnership with the Finnish-Swedish group Stora Enso to develop a lignin-based battery. The joint venture aims to establish a sustainable battery supply chain with anode materials that is based entirely on European raw materials and significantly reduces theCO2 footprint of batteries.
Trees consist of 20 to 30 percent lignin, which acts as a natural and strong binding agent. It is one of the largest renewable sources of carbon, according to Stora Enso in a press release. It is estimated that 50 million tons of lignin are already produced as a waste product in paper manufacturing. The raw material is separated from the pulp from which the paper is made using caustic soda.
"At our pilot plant in Kotka, Finland, we produce lignin-based carbon material as an alternative to fossil-based graphite, which is traditionally used in batteries. This allows us to develop and use bio-based chemical intermediates and by-products from the forest industry in a variety of ways," says Lehtonen. Lauri Lehtonen, SVP Innovations in Biomaterials at Stora Enso.
"With this partnership, we are tapping into a new source of sustainable raw materials and expanding the European battery value chain while developing a more cost-effective battery chemistry," commented Emma Nehrenheim, Chief Environmental Officer at Northvolt.
In addition, Stora Enso 2023 has also entered into a partnership with the electric car manufacturer Polestar with the aim of developing a truly climate-neutral car - Project Polestar 0 - by 2030.
Cover photo ©️Stora Enso
