An eggshell supercapacitor. Photo by the University of Alberta.
As material technology encounters developmental hurdles along conventional trajectories, scientists are finding innovative solutions in everyday, natural objects. An example may be seen in the electrical double-layer capacitor (EDLC), the typical type of supercapacitor seen in mobile electronic devices. EDLCs have been made of porous carbon, although the material's uneven surface leads to inefficiency.
Although the manipulation of the microstructure of porous carbon has delivered positive results, a recent paper by researchers in Alberta's Mitlin Group of Chemical and Materials Engineering reveals that the carbonization of common eggshells provides a superior platform for the development of supercapacitor electrodes. The scientists credit the stability of oxygen and nitrogen atoms in eggshell—in addition to the ubiquity, recyclability, biodegradability, and low cost of the material—for its success in this new function. Early tests demonstrate high and consistent levels of performance, suggesting that eggshell-powered electronics are not far off in the future.