**1.1 Lithium-ion battery (LIB)**

Lithium-ion battery (LIB) is a type of rechargeable battery in which Li ion moves during discharge from the negative electrode (cathode) to the positive electrode (anode) and then during charging Li ions move back from the anode to the cathode. There are four important components: anode, cathode, electrolyte, and separator [3, 4, 7]. Separator has the main role of keeping the electrodes apart, and, to allow the transport of only the charge carriers which in this case are lithium ions [8, 9]. Electrolyte has an important role in the transport as well and is usually made of lithium salts. Whereas, cathodes are made of lithium compounds like lithium cobaltates and lithium phosphates, and anode materials are usually made of 2D materials and their respective compounds. **Figure 2** shows a schematic representation of LIBs. When a source is supplied for charging of LIB, Li ions travel from the cathode through the electrolyte and separator to the anode and are intercalated into the 2D material. After fully charged, the source can be removed and the discharging starts in which the Li ions are desorbed from the anode and are transported back to the cathode [10]. The 2D materials that are preferred are graphene and carbonbased compounds because of their high conductivity and Li storage capability, not only on defect-free sites but defective as well [9, 11].
