Demineralization of a Carbon Material Derived from Palm Kernel Shells as a Process for the Enhancement of the Electrochemical Performance of Lithium–Sulfur Cells

Carbon materials derived from biomass have been widely used in Li-S batteries; however, the mineral matter present in the biomass could impact the properties of the carbons and affect the electrochemical performance. In this study, the removal of mineral matter from palm kernel shells is reported to identify the effect of minerals on the physicochemical properties of the derived activated carbon and correlate them to the electrochemical performance in Li-S batteries. The content of minerals such as silicon, iron, and potassium was decreased by acid washing. The textural and conductive properties of activated carbon were increased by the absence of minerals. Electrochemical results reveal that the demineralized sample used as a sulfur host can increase the capacity for high charge and discharge rates by 23%. Hence, the removal of mineral matter in the biomass is an important step to consider for the application of activated carbons as sulfur hosts in Li-S batteries.