Researchers in Sweden have built a car with a roof and battery made of wood. The roof is a full length solar panel used to recharge the car’s battery. Well, actually, both are made of lignin, one of the main components of the cell walls of most plants growing on dry land. Lignin is the second most abundant natural polymer in the world, cellulose being the most abundant. It is a byproduct of making paper from pulp wood.
What’s so great about lignin? According to Göran Lindbergh, Professor of Chemical Engineering at KTH Royal Institute of Technology in Stockholm, it is light in weight and recyclable. “The lightness of the material is especially important for electric cars because then batteries last longer,” he tells Engineering & Technology Magazine. “Lignin-based carbon fiber is cheaper than ordinary carbon fiber. Otherwise batteries made with lignin are indistinguishable from ordinary batteries.”
There’s a catch, of course. Isn’t there always? The car Lindbergh and his team created is just a model. Not surprisingly, it looks a lot like a production Volvo to the untrained eye, but what else would you expect from a bunch of Swedish researchers? They claim their tiny car is still a major leap forward for environmentally friendly automobiles.
Cars that use lignum based materials would be much lighter in weight that conventional cars. Weight is the enemy of electric cars. Reducing the weight of an electric car has the effect of giving it more range without using a larger battery. More weight means larger, more expensive batteries to lug all that excess poundage around. BMW has spent a fortune developing a carbon fiber chassis for its i3 sedan. If BMW used lignin based carbon fiber, the i3 would cost less to produce and weigh even less than it does.
Even in conventional cars, less weight translates into better fuel economy and lower carbon emissions. In addition, lignin based components can be recycled in a way that traditional carbon fiber cannot — another environmental plus for lignin.
The project began with research into lignin based electrodes for lithium ion batteries. The research has been funded by the Swedish Energy Agency. It is being conducted in cooperated with Swedish research institute Innventia and Swerea, a research group for industrial renewal and sustainable development.
Wood was one of the first materials used to make automobiles. Early cars were little more than modified wagons from the days when horsepower came from real horses. Could the world of transportation go back to using wood to make automobiles once again? Sometimes in the world of innovation, everything old is new again.