Synthesis and Characterization of Graphene Applied to Energy Storage: A Statistical and Electrochemical Study of the Effect of High-Energy Milling on the Efficiency of the Material

A supercapacitor is an energy storage device that has a much higher capacitance than conventional capacitors. It operates through electrical double layer mechanisms and electrochemical pseudocapacitance, allowing it to store and release energy quickly. For this task, graphene is an ideal candidate to perform this purpose. In this article, through multifactorial experimental planning, graphite was exfoliated in a ball mill over a period of 2, 4, 8, 12 h of milling. The samples were structurally analyzed by X-ray diffraction, showing the evolution of the crystalline phases present in the material, demonstrating that crystallinity increased 62 times with milling time. Raman spectroscopy analyses confirm the exfoliation of graphite and formation of graphene under the best conditions obtained in multifactorial planning. The electrochemical analysis showed the relation between the structural modification of the material through the milling process and its electrochemical behavior, indicating that the graphene obtained from the graphite milling reaches a specific capacitance of 274.75 F g-1, capacitance 53 times greater than that presented by the manually ground material (5.2 F g-1). This result indicates that high-energy ball milling can be an efficient synthetic route for the application of multilayer graphene as a supercapacitor.