When I think about batteries, I think ‘metal’. So that was why a recent story from Europe surprised me so much – the idea of producing batteries from trees. For me, it was yet another reminder of the circular economy revolution that is quietly happening in the bioeconomy. Wooden batteries mean: no mining and no shortage of expensive metals, and thus no harmful practices in extracting raw materials.
Scandinavian companies are paving the way for sustainable energy storage generated from their forests that is far less harmful to the environment than our conventional practices.
Finnish designers Stora Enso have built a production facility costing €10 million that will create renewable bio-based carbon, and now that the pilot facility has started operations, production of its wood-based carbon for batteries, known as Lignode, is being ramped up. Applications include electric vehicles and consumer electronics as well as large-scale energy storage systems.
A Swedish startup called Ligna Energy, which shared the grand prize in Northern Europe’s biggest energy innovation challenge last year, is doing the same thing. “We make batteries from forest materials based on organic electronic polymers and biopolymers, which are used throughout the lifetime of the energy storage and then recycled and burned as biofuel. Thereby we maximize the utilization of materials, enable fossil-free energy production and minimize the overall negative life cycle impact.”
The global battery market is projected to grow tenfold over the next decade as battery producers seek more sustainable materials, and since sustainability is becoming a top priority for the automotive industry, car manufacturers and battery producers are focusing heavily on reducing carbon emissions in electric cars, says Stora Enso.
Today, fossil-based carbon is used in the anodes of rechargeable batteries. By converting lignin separated from wood into carbon-based anode materials, the synthetic and non-renewable graphite material can be replaced.
“With our pilot plant now ramping up operations, Stora Enso is entering a new value chain in supplying more sustainable anode materials for batteries. With Lignode, we can provide a bio-based, cost-competitive and high-performance material to replace the conventionally used graphite. To serve the fast-growing anode materials market, we are now exploring strategic partnerships to accelerate scale-up and commercialisation in Europe,” says Markus Mannström, executive vice-president of Stora Enso’s biomaterials division.
Stora Enso, a leading global provider of renewable solutions in packaging, biomaterials, wooden constructions and paper, believes that everything that is made from fossil-based materials today can be made from a tree tomorrow. It has 23,000 employees, and sales of EUR 8.6 billion in over 50 countries.
In case you are, like me, trying to grasp the nature of ‘wooden batteries’, here is how Ligna Energy’s CEO, Peter Ringstad, and CTO Jakob Nilsson explained it on Swedish television:
“For those who wonder: The batteries do not look like wood and do not feel like wood. But it’s wood – or what’s inside wood in any case. They are made of lignin, a kind of glue that is found in wood and holds together the structure of a tree.
A lignin molecule can in some cases reach all the way from root to top. When the paper industry extracts cellulose, the lignin remains. Normally it’s just burned as biofuel. But we use it and modify it into battery material. There is residual current in lignin, the substance has the ability to charge and discharge electricity. We can do it several thousand times.
At a production facility in Linköping, the batteries are printed on thin plastic film. They are flexible and can be inserted into different types of frames, in sensors for example.
Smart buildings are a typical target market (for wooden batteries), so it may be property owners who need to be able to control energy and climate in their houses. Later on, there’s a possibility for large-scale storage of energy. Then it could be a solar power plant or a grid company that needs to stabilize its frequencies.
While they don’t work as car batteries because car batteries needs high energy density, they would work in charging stations, as an intermediate storage.
A big advantage of the technology is that very little waste is formed. We use waste, leftovers from paper production, so we do not take down any trees ourselves. And so much paper is still being produced that it is not a problem to get hold of lignin. You only need a few percent of the earth’s lignin to cover a very large storage need.”
Stora Enso’s pilot plant for producing lignin-based carbon materials for batteries is now operational. News release Jul. 21, 2021.
Wooden batteries are hitting the market – is this the future of clean energy? Euronews.green, Feb. 10, 2022
Ligna Energy website.