The clean energy economy, while certainly a step up from an oil-based economy, is not always so clean. Consider all the non-renewable resources required to power it: indium (solar panels), lithium (electric car batteries) and neodymium (wind turbines) are just some of the minerals necessary to fuel a transition away from oil. A truly sustainable economy wouldn’t need any of them. That’s why it we’re glad to hear that scientists are working on a new kind of battery cathode made out of lignin, a waste product in the paper-making process.
Researchers from Poznan University of Technology in Poland and Linköping University in Sweden have figured out how to combine lignin with polypyrrole (a conductive polymer) to create a battery cathode that could one day be used in energy storage. The lignin acts as an insulator, while the polypyrrole holds an electric charge.
The discovery is a potential boon for the renewable energy world. As the researchers explain in the journal Science, "Widespread application of electrical power storage may require more abundant materials than those available in inorganics (which often require rare metals), and at a lower cost. Materials for charge storage are desired from easily accessible and renewable sources. Combining cellulose materials and conjugated polymers for charge storage has … attracted attention."
The technology isn’t quite ready for commercialization—the lignin battery currently drops its charge when not in use, and in any case, it can take decades for a discovery like this to end up on the market. But it can’t come soon enough. Two decades from now, if we have successfully transitioned away from oil, we’ll be starving for solutions that don’t involve hard-to-find resources. Fortunately, we’ll probably never run out of lignin.