Biologically derived melanin electrodes in aqueous sodium-ion energy storage devices

Abstract

Significance Here we present important findings related to biologically derived pigments for potential use as battery electrodes. Namely, we report the synthesis, fabrication, and characterization of melanins as materials for use in aqueous sodium-ion batteries. We demonstrate the use of naturally occurring melanins as active electrode materials in charge storage devices. Furthermore, the performance of melanin anodes is comparable to many commonly available synthetic organic electrode materials. The structure–property relationships that govern the storage capacity in melanin materials were also elucidated. These findings suggest that the unique chemistry and nanostructure in natural melanins increase the charge storage capacity compared with synthetic melanin analogues.