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 an active component due to hydroquinone motifs or as a binder in electrodes. While usually it is blended or modified with unsustainable chemicals, we investigate crosslinking with glyoxal as a new route to obtain more benign electrodes. For combining the advantages of high charge (lignin as an active material) and electrode stability (lignin as a 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 mA h g(-1) at a discharge rate of 0.2 A g(-1) .