Americans consume 76 billion eggs per year, and while some of the eggshell waste is used for fertilizer or dietary supplements, the majority of these eggshells are thrown away. In a study, researchers at Wayne State University in Detroit have developed a method to recycle eggshells, using them as "chemical reactors" to synthesise sulfur-containing nanorods that can be used as battery electrodes.

A team of researchers, led by Dr. Da Deng, assistant professor of chemical engineering and materials science at Wayne State University, has found that baking algae in a furnace with argon gas at temperatures of 700-1000°C could convert it into a material called 'hard carbon'. This hard carbon can be used as high-capacity, low-cost electrodes for Na-ion batteries.