(190d) Rechargeable Magnesium Batteries with Carbon Based Cathode Materials

As the need for alternative energy storage systems grows, more research is being done to find suitable cathode materials for rechargeable magnesium battery systems. Magnesium batteries are being explored as an alternative to lithium-ion batteries because magnesium is more abundant, offers improved safety features, and has a higher volumetric capacity (3833 mAh/cm³ compared to lithium’s 2061 mAh/cm³). Compared to monovalent lithium ions, divalent magnesium ions possess a higher charge density, inducing strong interactions between magnesium ions and negatively charged transition metal oxide cathode materials. Fullerene, a carbon allotrope with covalently bonded carbon atoms forming a spherical cage-like structure, is investigated as a potential alternative cathode material due to its unique ability to distribute charges across multiple molecules. This has the potential to improve energy densities and diffusion rates, enhancing cycling capabilities. The compatibility of fullerene as an active material in rechargeable magnesium batteries is explored using galvanostatic cell cycling and surface microanalysis of cell components. Magnesium batteries with fullerene cathodes experience low initial capacities and have rapid capacity fade caused by material dissolution through the electrolyte. Additionally, the dispersion of C₆₀ in the electrolyte is observed, indicated by reduced capacity loss at higher cycling rates, the detection of soft shorts during cycling, and the presence of C₆₀ in the separator after cycling.