With more and more people buying electric cars and storing energy at home, the search is on for sustainable battery materials that are more widely available. A few years ago, a major paper producer in Finland noticed that demand for paper was starting to decline. The company hired engineers to look into the possibility of using lignin, a polymer found in trees, to produce batteries for electric vehicles. They found that they can extract lignin from waste pulp already being produced and then turn the lignin into a carbon anode material. The resulting carbon structure is irregular, which will help in making a battery that can be charged quickly.