How Everything Is Made on Instagram: "Lithium-ion batteries start with two carefully engineered layers: a graphite anode and a lithium-metal-oxide cathode. Each material is mixed into a slurry, spread onto thin foil sheets, and dried until it forms a uniform coating. These sheets are then rolled, cut, and stacked with a porous separator that keeps them from touching while still allowing ions to move freely. Once the layers are assembled, the battery cell is tightly wound or stacked into its fina