Converting eggs to flexible, all-solid supercapacitors

The rapid expansion of electrochemical energy storage market has imposed an impending need for low-cost, sustainable materials for high-performance electrodes, separators, and electrolytes. A rational strategy is to derive the electrochemical materials from renewable biomass. However, how to comprehensively and effectively utilize biomass remains challenging. Here, we report flexible, all-solid supercapacitors constructed with the materials entirely from eggs. Eggshells and white/yolk were used to produce 2D graphene-like carbon for constructing electrodes while egg white/yolk, on the other hand, was found to be a gel-like solid-state electrolyte with competitive ionic conductivity. With eggshell membrane as a superb separator, flexible, all-solid supercapacitors were assembled which exhibited superlative electrochemical performance and mechanical flexibility. The prototypical study inspires a smart approach to comprehensively and effectively use biomass materials for constructing energy storage devices. The eggshell-enabled graphene-like carbon and protein-derived solid-state electrolyte should find extensive applications in various fields.