More sustainable energy storage: lignin based electrodes with glyoxal crosslinking

Lignin is a promising material to be used in sustainable energy storage devices. It may act as active component due to hydroquinone motives or as binder in electrodes. While usually it is blended or modified with unsustainable chemicals, we investigate crosslinking with glyoxal as a new route to more benign electrodes. For combining advantages of high charge (lignin as active material) and electrode stability (lignin as binder), we chose a two-step process in which we first form lignin-carbon composites and subsequently crosslink lignin on the carbon. We discuss crosslinking of the material as well as influences on charge storage. Final electrodes benefit from combined faradaic and non-faradaic charge storage and reach a capacity of 80 mAh/g at a discharge rate of 0.2 A/g