Ten years of research at Linköping University have resulted in a wood-based battery that the company Ligna Energy in the neighboring city of Norrköping is now preparing to bring to the market.
“Our unique use of lignin is that it is the active battery component in the cathode. We use lignin as the main material, instead of lithium or lead, for example,” explains Peter Ringstad, CEO of Ligna Energy.
Here, Ligna Energy differs from lithium-ion manufacturers like Northvolt, who are exploring the possibility of replacing a smaller portion, the graphite-based anodes, with lignin.
“We also see potential with lignin anodes in our batteries and have a budding collaboration with another startup, Bright Day Graphene.”
This involves batteries made mostly from wood raw materials.
“We have tested lignin from many different sources to understand how sensitive we are to variations in the material. Currently, we primarily use a kraft lignin from Stora Enso. But we have also tried lignin from Domsjö and eucalyptus lignin from South America,” Peter Ringstad explains.
Ligna Energy has moved past the testing stage and is well on its way into the market phase.
“We have sold a thousand battery components for IoT applications. Now we are working on scaling up production, where we will manufacture batteries on a roll. We expect to have that, including the supplier network, ready by next autumn.”
The company is currently focusing on smart buildings.
“Our most advanced collaboration is with Epishine, which manufactures indoor solar cells. The combination of a harvester and a battery makes for a very powerful product. But we also have collaborations with other types of harvesters, such as those that extract energy from the ground using microorganisms in the soil to charge batteries.”
Ligna Energy also sees potential for its technology in larger energy storage solutions.
“We see that as the second step for the company, within three to four years. To achieve that, we need to further develop the material technology to achieve an energy density that is competitive in terms of cost per energy unit and cycle. We are aiming for an energy density level similar to lead batteries, which is about one-fifth of today’s lithium batteries.”
Wood-based battery manufacturing also facilitates recycling, a crucial aspect.
“You can essentially dispose of our small battery in any recycling bin without harming the environment. In the worst case, it can be burned as biofuel,” explains Peter Ringstad.
The challenge he currently faces is building sales and production capacity for sensor batteries.
“We don’t see significant technical challenges. For the larger energy storage solutions, it’s more about raising more capital to move forward.”
The main owner of Ligna Energy is the Wallenberg-controlled investment company Ruasset.
