Trees may help power your next electric car

No, we're not reverting to steam power – lignin just makes great cathodes

A Swedish-Finnish commercial partnership could be the first step toward commercially viable wood-derived batteries for electric vehicles.

Swedish battery maker Northvolt has signed a joint development agreement with Swedish-Finnish paper products company Stora Enso that lays out how the pair will work to develop batteries made with lignin, a resource Stora Enso has access to in abundance.

Lignins are a class of organic polymers derived from the cell walls of plants that grow on dry land, which acts as a binding agent. According to a statements from Northvolt and Stora Enso, trees are composed of 20 to 30 percent lignin, making them one of the "biggest renewable sources of carbon anywhere."

Stora Enso says it has the technology to turn lignin into a hard-carbon material called Lignode, which will be used as the anode material in the new batteries. Anodes are the portion of the battery that releases electrons, as Reg readers may know, while cathodes are the portion of the battery that absorbs them.

One of the key reasons for the partnership, said Johanna Hagelberg, Stora Enso's EVP for Biomaterials, was that it would mean Northvolt's device would be the world's first battery featuring an anode entirely sourced from European raw materials.

"[Lignode] will secure the strategic European supply of anode raw material, serving the sustainable battery needs for applications from mobility to stationary energy storage," Hagelberg said. Trees felled to make Lignode come from sustainably managed forests, the companies said in their joint statement. 

Stora Enso said its Lignode production is based out of its Sunila facility in Finland, which has a production capacity of 50,000 tons/year. Northvolt's role in the partnership will involve battery cell design, production process development, and scaling of the new technology.

Northvolt and Stora Enso didn't say if the batteries would be limited to EVs, and Hagelberg's statement indicates that stationary batteries were also part of the discussion. Still, it's likely that at least some of the production will go to automotive applications, as Volkswagen has invested "hundreds of millions" in Northvolt, Reuters said.

Volkswagen was notably an investor in Northvolt's recent $1.1 billion funding round, and Northvolt said the investment would go toward "developing manufacturing capacity to deliver on $55 billion in orders from key customers, including BMW, Fluence, Scania, Volvo Cars, and Volkswagen Group." 

This is not first co-partnership for both companies. Earlier this year, Northvolt bought a former Stora Enso paper factory in Borlänge, Sweden, which it intends to convert in to a facility for manufacturing battery cells. By the time it's fully operational in 2024, Northvolt said it will employ 1,000 people, utilize 100 percent clean, local energy, and produce more than 100GWh of cathode material annually.

Stora Enso's head of innovation, Mikael Hannus, told Reuters in 2017 that commercial production of lignin-based products was still 5-10 years away, meaning that 2022 was the earliest he predicted for product availability. We've asked Stora Enso if they think this partnership could move production forward faster, but we have yet to hear back. ®