Carbonized Chicken Eggshell Membranes with 3D Architectures as High-Performance Electrode Materials for Supercapacitors

Supercapacitor electrode materials are synthesized by carbonizing a common livestock biowaste in the form of chicken eggshell membranes. The carbonized eggshell membrane (CESM) is a three‐dimensional macroporous carbon film composed of interwoven connected carbon fibers containing around 10 wt% oxygen and 8 wt% nitrogen. Despite a relatively low surface area of 221 m2 g−1, exceptional specific capacitances of 297 F g−1 and 284 F g−1 are achieved in basic and acidic electrolytes, respectively, in a 3‐electrode system. Furthermore, the electrodes demonstrate excellent cycling stability: only 3% capacitance fading is observed after 10 000 cycles at a current density of 4 A g−1. These very attractive electrochemical properties are discussed in the context of the unique structure and chemistry of the material. High‐performance carbon materials for supercapacitors from eggshells: combining the long‐range 3D macroporous structure of one of the most common daily household waste products with its high content of N and O, the carbonized eggshell membrane shows a high capacitance of 297 F g−1 and less than 3% capacitance fading after 10 000 operation cycles in 1 M KOH.