A standard Li-ion battery has a cathode (conventionally the positive electrode), anode (conventionally the negative electrode) and a separator dipped in an electrolyte. During the charging cycle, Li ions deintercalate from the cathode and travel through the electrolyte to get intercalated in the anode. During the discharging cycle, the opposite motion of Li-ions takes place (i.e. from anode to cathode) via the electrolyte. Electrons on the other hand travel through the external circuit and thus can be used for driving our desired devices as shown in Figure .