LG Chem’s battery starts with thin strands of copper wire, which are coated with a nickel-tin (Ni-Sn) alloy to create the anode. These strands are twisted into a yarn, and then wrapped tightly around a 1.5mm-diameter rod. The rod is removed, leaving a strong spring. Next, aluminium wire is wrapped around the spring, and then the whole caboodle is dragged through a slurry of lithium cobalt oxide, which coats the aluminium wire and becomes the cathode. Finally, the anode-cathode spring is wrapped in a protective outer coating, and then an electrolyte is poured down the middle of the hollow spring to create a battery.